< draft-ietf-anima-autonomic-control-plane-28.txt   draft-ietf-anima-autonomic-control-plane-29.txt >
ANIMA WG T. Eckert, Ed. ANIMA WG T. Eckert, Ed.
Internet-Draft Futurewei USA Internet-Draft Futurewei USA
Intended status: Standards Track M. Behringer, Ed. Intended status: Standards Track M. Behringer, Ed.
Expires: January 29, 2021 Expires: March 14, 2021
S. Bjarnason S. Bjarnason
Arbor Networks Arbor Networks
July 28, 2020 September 10, 2020
An Autonomic Control Plane (ACP) An Autonomic Control Plane (ACP)
draft-ietf-anima-autonomic-control-plane-28 draft-ietf-anima-autonomic-control-plane-29
Abstract Abstract
Autonomic functions need a control plane to communicate, which Autonomic functions need a control plane to communicate, which
depends on some addressing and routing. This Autonomic Control Plane depends on some addressing and routing. This Autonomic Control Plane
should ideally be self-managing, and as independent as possible of should ideally be self-managing, and as independent as possible of
configuration. This document defines such a plane and calls it the configuration. This document defines such a plane and calls it the
"Autonomic Control Plane", with the primary use as a control plane "Autonomic Control Plane", with the primary use as a control plane
for autonomic functions. It also serves as a "virtual out-of-band for autonomic functions. It also serves as a "virtual out-of-band
channel" for Operations, Administration and Management (OAM) channel" for Operations, Administration and Management (OAM)
skipping to change at page 1, line 43 skipping to change at page 1, line 43
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 29, 2021. This Internet-Draft will expire on March 14, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents (https://trustee.ietf.org/
(https://trustee.ietf.org/license-info) in effect on the date of license-info) in effect on the date of publication of this document.
publication of this document. Please review these documents Please review these documents carefully, as they describe your rights
carefully, as they describe your rights and restrictions with respect and restrictions with respect to this document. Code Components
to this document. Code Components extracted from this document must extracted from this document must include Simplified BSD License text
include Simplified BSD License text as described in Section 4.e of as described in Section 4.e of the Trust Legal Provisions and are
the Trust Legal Provisions and are provided without warranty as provided without warranty as described in the Simplified BSD License.
described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction (Informative) . . . . . . . . . . . . . . . . . 6 1. Introduction (Informative) . . . . . . . . . . . . . . . . . 6
1.1. Applicability and Scope . . . . . . . . . . . . . . . . . 9 1.1. Applicability and Scope . . . . . . . . . . . . . . . . . 9
2. Acronyms and Terminology (Informative) . . . . . . . . . . . 10 2. Acronyms and Terminology (Informative) . . . . . . . . . . . 10
3. Use Cases for an Autonomic Control Plane (Informative) . . . 17 3. Use Cases for an Autonomic Control Plane (Informative) . . . 16
3.1. An Infrastructure for Autonomic Functions . . . . . . . . 17 3.1. An Infrastructure for Autonomic Functions . . . . . . . . 16
3.2. Secure Bootstrap over a not configured Network . . . . . 17 3.2. Secure Bootstrap over a not configured Network . . . . . 17
3.3. Data-Plane Independent Permanent Reachability . . . . . . 18 3.3. Data-Plane Independent Permanent Reachability . . . . . . 17
4. Requirements (Informative) . . . . . . . . . . . . . . . . . 19 4. Requirements (Informative) . . . . . . . . . . . . . . . . . 19
5. Overview (Informative) . . . . . . . . . . . . . . . . . . . 20 5. Overview (Informative) . . . . . . . . . . . . . . . . . . . 20
6. Self-Creation of an Autonomic Control Plane (ACP) (Normative) 22 6. Self-Creation of an Autonomic Control Plane (ACP)
6.1. ACP Domain, Certificate and Network . . . . . . . . . . . 23 (Normative) . . . . . . . . . . . . . . . . . . . . . . . 21
6.1.1. ACP Certificates . . . . . . . . . . . . . . . . . . 24 6.1. Requirements for use of Transport Layer Security (TLS) . 22
6.1.2. ACP Certificate AcpNodeName . . . . . . . . . . . . . 26 6.2. ACP Domain, Certificate and Network . . . . . . . . . . . 23
6.1.2.1. AcpNodeName ASN.1 Module . . . . . . . . . . . . 29 6.2.1. ACP Certificates . . . . . . . . . . . . . . . . . . 24
6.1.3. ACP domain membership check . . . . . . . . . . . . . 30 6.2.2. ACP Certificate AcpNodeName . . . . . . . . . . . . . 26
6.1.3.1. Realtime clock and Time Validation . . . . . . . 32 6.2.2.1. AcpNodeName ASN.1 Module . . . . . . . . . . . . 29
6.1.4. Trust Anchors (TA) . . . . . . . . . . . . . . . . . 33 6.2.3. ACP domain membership check . . . . . . . . . . . . . 30
6.1.5. Certificate and Trust Anchor Maintenance . . . . . . 34 6.2.3.1. Realtime clock and Time Validation . . . . . . . 32
6.1.5.1. GRASP objective for EST server . . . . . . . . . 35 6.2.4. Trust Anchors (TA) . . . . . . . . . . . . . . . . . 33
6.1.5.2. Renewal . . . . . . . . . . . . . . . . . . . . . 36 6.2.5. Certificate and Trust Anchor Maintenance . . . . . . 34
6.1.5.3. Certificate Revocation Lists (CRLs) . . . . . . . 37 6.2.5.1. GRASP objective for EST server . . . . . . . . . 35
6.1.5.4. Lifetimes . . . . . . . . . . . . . . . . . . . . 37 6.2.5.2. Renewal . . . . . . . . . . . . . . . . . . . . . 37
6.1.5.5. Re-enrollment . . . . . . . . . . . . . . . . . . 38 6.2.5.3. Certificate Revocation Lists (CRLs) . . . . . . . 37
6.1.5.6. Failing Certificates . . . . . . . . . . . . . . 39 6.2.5.4. Lifetimes . . . . . . . . . . . . . . . . . . . . 38
6.2. ACP Adjacency Table . . . . . . . . . . . . . . . . . . . 40 6.2.5.5. Re-enrollment . . . . . . . . . . . . . . . . . . 38
6.3. Neighbor Discovery with DULL GRASP . . . . . . . . . . . 40 6.2.5.6. Failing Certificates . . . . . . . . . . . . . . 40
6.4. Candidate ACP Neighbor Selection . . . . . . . . . . . . 44 6.3. ACP Adjacency Table . . . . . . . . . . . . . . . . . . . 40
6.5. Channel Selection . . . . . . . . . . . . . . . . . . . . 44 6.4. Neighbor Discovery with DULL GRASP . . . . . . . . . . . 41
6.6. Candidate ACP Neighbor verification . . . . . . . . . . . 48 6.5. Candidate ACP Neighbor Selection . . . . . . . . . . . . 45
6.7. Security Association (Secure Channel) protocols . . . . . 48 6.6. Channel Selection . . . . . . . . . . . . . . . . . . . . 45
6.7.1. General considerations . . . . . . . . . . . . . . . 49 6.7. Candidate ACP Neighbor verification . . . . . . . . . . . 49
6.7.2. Common requirements . . . . . . . . . . . . . . . . . 49 6.8. Security Association (Secure Channel) protocols . . . . . 49
6.7.3. ACP via IPsec . . . . . . . . . . . . . . . . . . . . 51 6.8.1. General considerations . . . . . . . . . . . . . . . 50
6.7.3.1. Native IPsec . . . . . . . . . . . . . . . . . . 51 6.8.2. Common requirements . . . . . . . . . . . . . . . . . 51
6.7.3.1.1. RFC8221 (IPsec/ESP) . . . . . . . . . . . . . 51 6.8.3. ACP via IPsec . . . . . . . . . . . . . . . . . . . . 52
6.7.3.1.2. RFC8247 (IKEv2) . . . . . . . . . . . . . . . 53 6.8.3.1. Native IPsec . . . . . . . . . . . . . . . . . . 52
6.8.3.1.1. RFC8221 (IPsec/ESP) . . . . . . . . . . . . . 53
6.7.3.2. IPsec with GRE encapsulation . . . . . . . . . . 54 6.8.3.1.2. RFC8247 (IKEv2) . . . . . . . . . . . . . . . 54
6.7.4. ACP via DTLS . . . . . . . . . . . . . . . . . . . . 55 6.8.3.2. IPsec with GRE encapsulation . . . . . . . . . . 55
6.7.5. ACP Secure Channel Profiles . . . . . . . . . . . . . 56 6.8.4. ACP via DTLS . . . . . . . . . . . . . . . . . . . . 56
6.8. GRASP in the ACP . . . . . . . . . . . . . . . . . . . . 57 6.8.5. ACP Secure Channel Profiles . . . . . . . . . . . . . 58
6.8.1. GRASP as a core service of the ACP . . . . . . . . . 57 6.9. GRASP in the ACP . . . . . . . . . . . . . . . . . . . . 59
6.8.2. ACP as the Security and Transport substrate for GRASP 58 6.9.1. GRASP as a core service of the ACP . . . . . . . . . 59
6.8.2.1. Discussion . . . . . . . . . . . . . . . . . . . 61 6.9.2. ACP as the Security and Transport substrate for
6.9. Context Separation . . . . . . . . . . . . . . . . . . . 62 GRASP . . . . . . . . . . . . . . . . . . . . . . . . 59
6.10. Addressing inside the ACP . . . . . . . . . . . . . . . . 62 6.9.2.1. Discussion . . . . . . . . . . . . . . . . . . . 62
6.10.1. Fundamental Concepts of Autonomic Addressing . . . . 62 6.10. Context Separation . . . . . . . . . . . . . . . . . . . 63
6.10.2. The ACP Addressing Base Scheme . . . . . . . . . . . 64 6.11. Addressing inside the ACP . . . . . . . . . . . . . . . . 63
6.10.3. ACP Zone Addressing Sub-Scheme (ACP-Zone) . . . . . 65 6.11.1. Fundamental Concepts of Autonomic Addressing . . . . 63
6.10.4. ACP Manual Addressing Sub-Scheme (ACP-Manual) . . . 67 6.11.2. The ACP Addressing Base Scheme . . . . . . . . . . . 65
6.10.5. ACP Vlong Addressing Sub-Scheme (ACP-VLong-8/ACP- 6.11.3. ACP Zone Addressing Sub-Scheme (ACP-Zone) . . . . . 67
VLong-16 . . . . . . . . . . . . . . . . . . . . . . 68 6.11.4. ACP Manual Addressing Sub-Scheme (ACP-Manual) . . . 68
6.10.6. Other ACP Addressing Sub-Schemes . . . . . . . . . . 69 6.11.5. ACP Vlong Addressing Sub-Scheme (ACP-VLong-8/
6.10.7. ACP Registrars . . . . . . . . . . . . . . . . . . . 70 ACP-VLong-16 . . . . . . . . . . . . . . . . . . . . 69
6.10.7.1. Use of BRSKI or other Mechanism/Protocols . . . 70 6.11.6. Other ACP Addressing Sub-Schemes . . . . . . . . . . 70
6.10.7.2. Unique Address/Prefix allocation . . . . . . . . 71 6.11.7. ACP Registrars . . . . . . . . . . . . . . . . . . . 71
6.10.7.3. Addressing Sub-Scheme Policies . . . . . . . . . 72 6.11.7.1. Use of BRSKI or other Mechanism/Protocols . . . 71
6.10.7.4. Address/Prefix Persistence . . . . . . . . . . . 73 6.11.7.2. Unique Address/Prefix allocation . . . . . . . . 72
6.10.7.5. Further Details . . . . . . . . . . . . . . . . 73 6.11.7.3. Addressing Sub-Scheme Policies . . . . . . . . . 72
6.11. Routing in the ACP . . . . . . . . . . . . . . . . . . . 73 6.11.7.4. Address/Prefix Persistence . . . . . . . . . . . 74
6.11.1. ACP RPL Profile . . . . . . . . . . . . . . . . . . 74 6.11.7.5. Further Details . . . . . . . . . . . . . . . . 74
6.11.1.1. Overview . . . . . . . . . . . . . . . . . . . . 74 6.12. Routing in the ACP . . . . . . . . . . . . . . . . . . . 74
6.11.1.1.1. Single Instance . . . . . . . . . . . . . . 74 6.12.1. ACP RPL Profile . . . . . . . . . . . . . . . . . . 75
6.11.1.1.2. Reconvergence . . . . . . . . . . . . . . . 75 6.12.1.1. Overview . . . . . . . . . . . . . . . . . . . . 75
6.11.1.2. RPL Instances . . . . . . . . . . . . . . . . . 76 6.12.1.1.1. Single Instance . . . . . . . . . . . . . . 75
6.11.1.3. Storing vs. Non-Storing Mode . . . . . . . . . . 76 6.12.1.1.2. Reconvergence . . . . . . . . . . . . . . . 76
6.11.1.4. DAO Policy . . . . . . . . . . . . . . . . . . . 76 6.12.1.2. RPL Instances . . . . . . . . . . . . . . . . . 77
6.11.1.5. Path Metric . . . . . . . . . . . . . . . . . . 76 6.12.1.3. Storing vs. Non-Storing Mode . . . . . . . . . . 77
6.11.1.6. Objective Function . . . . . . . . . . . . . . . 76 6.12.1.4. DAO Policy . . . . . . . . . . . . . . . . . . . 77
6.11.1.7. DODAG Repair . . . . . . . . . . . . . . . . . . 76 6.12.1.5. Path Metric . . . . . . . . . . . . . . . . . . 77
6.11.1.8. Multicast . . . . . . . . . . . . . . . . . . . 77 6.12.1.6. Objective Function . . . . . . . . . . . . . . . 77
6.11.1.9. Security . . . . . . . . . . . . . . . . . . . . 77 6.12.1.7. DODAG Repair . . . . . . . . . . . . . . . . . . 77
6.11.1.10. P2P communications . . . . . . . . . . . . . . . 77 6.12.1.8. Multicast . . . . . . . . . . . . . . . . . . . 78
6.11.1.11. IPv6 address configuration . . . . . . . . . . . 77 6.12.1.9. Security . . . . . . . . . . . . . . . . . . . . 78
6.11.1.12. Administrative parameters . . . . . . . . . . . 78 6.12.1.10. P2P communications . . . . . . . . . . . . . . . 78
6.11.1.13. RPL Packet Information . . . . . . . . . . . . . 78 6.12.1.11. IPv6 address configuration . . . . . . . . . . . 78
6.11.1.14. Unknown Destinations . . . . . . . . . . . . . . 78 6.12.1.12. Administrative parameters . . . . . . . . . . . 79
6.12. General ACP Considerations . . . . . . . . . . . . . . . 79 6.12.1.13. RPL Packet Information . . . . . . . . . . . . . 79
6.12.1. Performance . . . . . . . . . . . . . . . . . . . . 79 6.12.1.14. Unknown Destinations . . . . . . . . . . . . . . 79
6.12.2. Addressing of Secure Channels . . . . . . . . . . . 79 6.13. General ACP Considerations . . . . . . . . . . . . . . . 80
6.12.3. MTU . . . . . . . . . . . . . . . . . . . . . . . . 80 6.13.1. Performance . . . . . . . . . . . . . . . . . . . . 80
6.12.4. Multiple links between nodes . . . . . . . . . . . . 80 6.13.2. Addressing of Secure Channels . . . . . . . . . . . 80
6.12.5. ACP interfaces . . . . . . . . . . . . . . . . . . . 80 6.13.3. MTU . . . . . . . . . . . . . . . . . . . . . . . . 81
6.12.5.1. ACP loopback interfaces . . . . . . . . . . . . 80 6.13.4. Multiple links between nodes . . . . . . . . . . . . 81
6.12.5.2. ACP virtual interfaces . . . . . . . . . . . . . 83 6.13.5. ACP interfaces . . . . . . . . . . . . . . . . . . . 82
6.12.5.2.1. ACP point-to-point virtual interfaces . . . 83 6.13.5.1. ACP loopback interfaces . . . . . . . . . . . . 82
6.12.5.2.2. ACP multi-access virtual interfaces . . . . 83 6.13.5.2. ACP virtual interfaces . . . . . . . . . . . . . 84
7. ACP support on L2 switches/ports (Normative) . . . . . . . . 85 6.13.5.2.1. ACP point-to-point virtual interfaces . . . 84
7.1. Why (Benefits of ACP on L2 switches) . . . . . . . . . . 86 6.13.5.2.2. ACP multi-access virtual interfaces . . . . 84
7.2. How (per L2 port DULL GRASP) . . . . . . . . . . . . . . 87 7. ACP support on L2 switches/ports (Normative) . . . . . . . . 87
8. Support for Non-ACP Components (Normative) . . . . . . . . . 88 7.1. Why (Benefits of ACP on L2 switches) . . . . . . . . . . 87
8.1. ACP Connect . . . . . . . . . . . . . . . . . . . . . . . 88 7.2. How (per L2 port DULL GRASP) . . . . . . . . . . . . . . 88
8.1.1. Non-ACP Controller / NMS system . . . . . . . . . . . 88 8. Support for Non-ACP Components (Normative) . . . . . . . . . 89
8.1.2. Software Components . . . . . . . . . . . . . . . . . 91 8.1. ACP Connect . . . . . . . . . . . . . . . . . . . . . . . 89
8.1.3. Auto Configuration . . . . . . . . . . . . . . . . . 92 8.1.1. Non-ACP Controller / NMS system . . . . . . . . . . . 90
8.1.4. Combined ACP/Data-Plane Interface (VRF Select) . . . 93 8.1.2. Software Components . . . . . . . . . . . . . . . . . 92
8.1.5. Use of GRASP . . . . . . . . . . . . . . . . . . . . 94 8.1.3. Auto Configuration . . . . . . . . . . . . . . . . . 93
8.2. Connecting ACP islands over Non-ACP L3 networks (Remote 8.1.4. Combined ACP/Data-Plane Interface (VRF Select) . . . 94
ACP neighbors) . . . . . . . . . . . . . . . . . . . . . 95 8.1.5. Use of GRASP . . . . . . . . . . . . . . . . . . . . 96
8.2.1. Configured Remote ACP neighbor . . . . . . . . . . . 95 8.2. Connecting ACP islands over Non-ACP L3 networks (Remote ACP
8.2.2. Tunneled Remote ACP Neighbor . . . . . . . . . . . . 96 neighbors) . . . . . . . . . . . . . . . . . . . . . . . 97
8.2.3. Summary . . . . . . . . . . . . . . . . . . . . . . . 97 8.2.1. Configured Remote ACP neighbor . . . . . . . . . . . 97
9. ACP Operations (Informative) . . . . . . . . . . . . . . . . 97 8.2.2. Tunneled Remote ACP Neighbor . . . . . . . . . . . . 98
9.1. ACP (and BRSKI) Diagnostics . . . . . . . . . . . . . . . 98 8.2.3. Summary . . . . . . . . . . . . . . . . . . . . . . . 98
9.1.1. Secure Channel Peer diagnostics . . . . . . . . . . . 102 9. ACP Operations (Informative) . . . . . . . . . . . . . . . . 99
9.2. ACP Registrars . . . . . . . . . . . . . . . . . . . . . 103 9.1. ACP (and BRSKI) Diagnostics . . . . . . . . . . . . . . . 99
9.2.1. Registrar interactions . . . . . . . . . . . . . . . 103 9.1.1. Secure Channel Peer diagnostics . . . . . . . . . . . 103
9.2.2. Registrar Parameter . . . . . . . . . . . . . . . . . 104 9.2. ACP Registrars . . . . . . . . . . . . . . . . . . . . . 104
9.2.3. Certificate renewal and limitations . . . . . . . . . 105 9.2.1. Registrar interactions . . . . . . . . . . . . . . . 104
9.2.4. ACP Registrars with sub-CA . . . . . . . . . . . . . 106 9.2.2. Registrar Parameter . . . . . . . . . . . . . . . . . 105
9.2.5. Centralized Policy Control . . . . . . . . . . . . . 106 9.2.3. Certificate renewal and limitations . . . . . . . . . 106
9.3. Enabling and disabling ACP/ANI . . . . . . . . . . . . . 107 9.2.4. ACP Registrars with sub-CA . . . . . . . . . . . . . 107
9.3.1. Filtering for non-ACP/ANI packets . . . . . . . . . . 107 9.2.5. Centralized Policy Control . . . . . . . . . . . . . 107
9.3.2. Admin Down State . . . . . . . . . . . . . . . . . . 108 9.3. Enabling and disabling ACP/ANI . . . . . . . . . . . . . 108
9.3.2.1. Security . . . . . . . . . . . . . . . . . . . . 109 9.3.1. Filtering for non-ACP/ANI packets . . . . . . . . . . 108
9.3.2.2. Fast state propagation and Diagnostics . . . . . 109 9.3.2. Admin Down State . . . . . . . . . . . . . . . . . . 109
9.3.2.3. Low Level Link Diagnostics . . . . . . . . . . . 110 9.3.2.1. Security . . . . . . . . . . . . . . . . . . . . 110
9.3.2.4. Power Consumption Issues . . . . . . . . . . . . 111 9.3.2.2. Fast state propagation and Diagnostics . . . . . 110
9.3.3. Interface level ACP/ANI enable . . . . . . . . . . . 111 9.3.2.3. Low Level Link Diagnostics . . . . . . . . . . . 111
9.3.4. Which interfaces to auto-enable? . . . . . . . . . . 111 9.3.2.4. Power Consumption Issues . . . . . . . . . . . . 112
9.3.5. Node Level ACP/ANI enable . . . . . . . . . . . . . . 113 9.3.3. Interface level ACP/ANI enable . . . . . . . . . . . 112
9.3.5.1. Brownfield nodes . . . . . . . . . . . . . . . . 113 9.3.4. Which interfaces to auto-enable? . . . . . . . . . . 112
9.3.5.2. Greenfield nodes . . . . . . . . . . . . . . . . 114 9.3.5. Node Level ACP/ANI enable . . . . . . . . . . . . . . 114
9.3.6. Undoing ANI/ACP enable . . . . . . . . . . . . . . . 114 9.3.5.1. Brownfield nodes . . . . . . . . . . . . . . . . 114
9.3.7. Summary . . . . . . . . . . . . . . . . . . . . . . . 115 9.3.5.2. Greenfield nodes . . . . . . . . . . . . . . . . 115
9.4. Partial or Incremental adoption . . . . . . . . . . . . . 115 9.3.6. Undoing ANI/ACP enable . . . . . . . . . . . . . . . 116
9.5. Configuration and the ACP (summary) . . . . . . . . . . . 116 9.3.7. Summary . . . . . . . . . . . . . . . . . . . . . . . 116
10. Summary: Benefits (Informative) . . . . . . . . . . . . . . . 117 9.4. Partial or Incremental adoption . . . . . . . . . . . . . 117
10.1. Self-Healing Properties . . . . . . . . . . . . . . . . 118 9.5. Configuration and the ACP (summary) . . . . . . . . . . . 118
10.2. Self-Protection Properties . . . . . . . . . . . . . . . 119 10. Summary: Benefits (Informative) . . . . . . . . . . . . . . . 119
10.2.1. From the outside . . . . . . . . . . . . . . . . . . 119 10.1. Self-Healing Properties . . . . . . . . . . . . . . . . 119
10.2.2. From the inside . . . . . . . . . . . . . . . . . . 120 10.2. Self-Protection Properties . . . . . . . . . . . . . . . 121
10.3. The Administrator View . . . . . . . . . . . . . . . . . 121 10.2.1. From the outside . . . . . . . . . . . . . . . . . . 121
10.2.2. From the inside . . . . . . . . . . . . . . . . . . 122
11. Security Considerations . . . . . . . . . . . . . . . . . . . 122 10.3. The Administrator View . . . . . . . . . . . . . . . . . 123
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 125 11. Security Considerations . . . . . . . . . . . . . . . . . . . 124
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 125 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 129
14. Change log [RFC Editor: Please remove] . . . . . . . . . . . 126 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 130
14.1. Summary of changes since entering IESG review . . . . . 126 14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 130
14.1.1. Reviews (while in IESG review status) / status . . . 126 15. Change log [RFC Editor: Please remove] . . . . . . . . . . . 131
14.1.2. BRSKI / ACP registrar related enhancements . . . . . 127 15.1. Summary of changes since entering IESG review . . . . . 131
14.1.3. Normative enhancements since start of IESG review . 127 15.1.1. Reviews (while in IESG review status) / status . . . 131
14.1.4. Explanatory enhancements since start of IESG review 128 15.1.2. BRSKI / ACP registrar related enhancements . . . . . 132
14.2. draft-ietf-anima-autonomic-control-plane-28 . . . . . . 129 15.1.3. Normative enhancements since start of IESG review . 132
14.3. draft-ietf-anima-autonomic-control-plane-27 . . . . . . 130 15.1.4. Explanatory enhancements since start of IESG
14.4. draft-ietf-anima-autonomic-control-plane-26 . . . . . . 130 review . . . . . . . . . . . . . . . . . . . . . . . 133
14.5. draft-ietf-anima-autonomic-control-plane-25 . . . . . . 131 15.2. draft-ietf-anima-autonomic-control-plane-29 . . . . . . 134
14.6. draft-ietf-anima-autonomic-control-plane-24 . . . . . . 135 15.3. draft-ietf-anima-autonomic-control-plane-28 . . . . . . 137
14.7. draft-ietf-anima-autonomic-control-plane-23 . . . . . . 135 15.4. draft-ietf-anima-autonomic-control-plane-27 . . . . . . 138
14.8. draft-ietf-anima-autonomic-control-plane-22 . . . . . . 136 15.5. draft-ietf-anima-autonomic-control-plane-26 . . . . . . 138
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 138 15.6. draft-ietf-anima-autonomic-control-plane-25 . . . . . . 139
15.1. Normative References . . . . . . . . . . . . . . . . . . 138 15.7. draft-ietf-anima-autonomic-control-plane-24 . . . . . . 143
15.2. Informative References . . . . . . . . . . . . . . . . . 142 15.8. draft-ietf-anima-autonomic-control-plane-23 . . . . . . 143
15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 149 15.9. draft-ietf-anima-autonomic-control-plane-22 . . . . . . 145
Appendix A. Background and Futures (Informative) . . . . . . . . 150 16. Normative References . . . . . . . . . . . . . . . . . . . . 147
A.1. ACP Address Space Schemes . . . . . . . . . . . . . . . . 150 17. Informative References . . . . . . . . . . . . . . . . . . . 150
A.2. BRSKI Bootstrap (ANI) . . . . . . . . . . . . . . . . . . 150 Appendix A. Background and Futures (Informative) . . . . . . . . 158
A.3. ACP Neighbor discovery protocol selection . . . . . . . . 152 A.1. ACP Address Space Schemes . . . . . . . . . . . . . . . . 158
A.3.1. LLDP . . . . . . . . . . . . . . . . . . . . . . . . 152 A.2. BRSKI Bootstrap (ANI) . . . . . . . . . . . . . . . . . . 159
A.3.2. mDNS and L2 support . . . . . . . . . . . . . . . . . 152 A.3. ACP Neighbor discovery protocol selection . . . . . . . . 160
A.3.3. Why DULL GRASP . . . . . . . . . . . . . . . . . . . 152 A.3.1. LLDP . . . . . . . . . . . . . . . . . . . . . . . . 160
A.4. Choice of routing protocol (RPL) . . . . . . . . . . . . 153 A.3.2. mDNS and L2 support . . . . . . . . . . . . . . . . . 161
A.5. ACP Information Distribution and multicast . . . . . . . 154 A.3.3. Why DULL GRASP . . . . . . . . . . . . . . . . . . . 161
A.6. Extending ACP channel negotiation (via GRASP) . . . . . . 155 A.4. Choice of routing protocol (RPL) . . . . . . . . . . . . 161
A.7. CAs, domains and routing subdomains . . . . . . . . . . . 157 A.5. ACP Information Distribution and multicast . . . . . . . 163
A.8. Intent for the ACP . . . . . . . . . . . . . . . . . . . 158 A.6. Extending ACP channel negotiation (via GRASP) . . . . . . 164
A.9. Adopting ACP concepts for other environments . . . . . . 159 A.7. CAs, domains and routing subdomains . . . . . . . . . . . 166
A.10. Further (future) options . . . . . . . . . . . . . . . . 161 A.8. Intent for the ACP . . . . . . . . . . . . . . . . . . . 167
A.10.1. Auto-aggregation of routes . . . . . . . . . . . . . 161 A.9. Adopting ACP concepts for other environments . . . . . . 168
A.10.2. More options for avoiding IPv6 Data-Plane dependency 161 A.10. Further (future) options . . . . . . . . . . . . . . . . 170
A.10.3. ACP APIs and operational models (YANG) . . . . . . . 162 A.10.1. Auto-aggregation of routes . . . . . . . . . . . . . 170
A.10.4. RPL enhancements . . . . . . . . . . . . . . . . . . 162 A.10.2. More options for avoiding IPv6 Data-Plane
A.10.5. Role assignments . . . . . . . . . . . . . . . . . . 163 dependencies . . . . . . . . . . . . . . . . . . . . 170
A.10.6. Autonomic L3 transit . . . . . . . . . . . . . . . . 163 A.10.3. ACP APIs and operational models (YANG) . . . . . . . 171
A.10.7. Diagnostics . . . . . . . . . . . . . . . . . . . . 164 A.10.4. RPL enhancements . . . . . . . . . . . . . . . . . . 171
A.10.8. Avoiding and dealing with compromised ACP nodes . . 164 A.10.5. Role assignments . . . . . . . . . . . . . . . . . . 172
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 165 A.10.6. Autonomic L3 transit . . . . . . . . . . . . . . . . 172
A.10.7. Diagnostics . . . . . . . . . . . . . . . . . . . . 172
A.10.8. Avoiding and dealing with compromised ACP nodes . . 173
A.10.9. Detecting ACP secure channel downgrade attacks . . . 174
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 175
1. Introduction (Informative) 1. Introduction (Informative)
Autonomic Networking is a concept of self-management: Autonomic Autonomic Networking is a concept of self-management: Autonomic
functions self-configure, and negotiate parameters and settings functions self-configure, and negotiate parameters and settings
across the network. [RFC7575] defines the fundamental ideas and across the network. [RFC7575] defines the fundamental ideas and
design goals of Autonomic Networking. A gap analysis of Autonomic design goals of Autonomic Networking. A gap analysis of Autonomic
Networking is given in [RFC7576]. The reference architecture for Networking is given in [RFC7576]. The reference architecture for
Autonomic Networking in the IETF is specified in the document Autonomic Networking in the IETF is specified in the document
[I-D.ietf-anima-reference-model]. [I-D.ietf-anima-reference-model].
skipping to change at page 6, line 50 skipping to change at page 6, line 50
In increasingly automated networks either centralized management In increasingly automated networks either centralized management
systems or distributed autonomic service agents in the network systems or distributed autonomic service agents in the network
require a control plane which is independent of the configuration of require a control plane which is independent of the configuration of
the network they manage, to avoid impacting their own operations the network they manage, to avoid impacting their own operations
through the configuration actions they take. through the configuration actions they take.
This document describes a modular design for a self-forming, self- This document describes a modular design for a self-forming, self-
managing and self-protecting ACP, which is a virtual out-of-band managing and self-protecting ACP, which is a virtual out-of-band
network designed to be as independent as possible of configuration, network designed to be as independent as possible of configuration,
addressing and routing and similar self-dependency problems in addressing and routing to avoid the self-dependency problems of
current IP networks, but which is still operating in-band on the same current IP networks while still operating in-band on the same
physical network that it is controlling and managing. The ACP design physical network that it is controlling and managing. The ACP design
is therefore intended to combine as good as possible the resilience is therefore intended to combine as well as possible the resilience
of out-of-band management networks with the low-cost of traditional of out-of-band management networks with the low-cost of traditional
IP in-band network management. The details how this is achieved are IP in-band network management. The details how this is achieved are
described in Section 6. described in Section 6.
In a fully autonomic network node without legacy control or In a fully autonomic network node without legacy control or
management functions/protocols, the Data-Plane would be for example management functions/protocols, the Data-Plane would be for example
just a forwarding plane for "Data" IPv6 packets, aka: packets that just a forwarding plane for "Data" IPv6 packets, aka: packets other
are not forwarded by the ACP itself such as control or management than the control and management plane packets that are forwarded by
plane packets. In such networks/nodes, there would be no non- the ACP itself. In such networks/nodes, there would be no non-
autonomous control or non-autonomous management plane. autonomous control or non-autonomous management plane.
Routing protocols for example would be built inside the ACP as so- Routing protocols for example would be built inside the ACP as so-
called autonomous functions via autonomous service agents, leveraging called autonomous functions via autonomous service agents, leveraging
the ACPs functions instead of implementing them seperately for each the ACP's functions instead of implementing them seperately for each
protocol: discovery, automatically established authenticated and protocol: discovery, automatically established authenticated and
encrypted local and distant peer connectivity for control and encrypted local and distant peer connectivity for control and
management traffic and common control/management protocol session and management traffic, and common control/management protocol session
presentation functions. and presentation functions.
When ACP functionality is added to nodes that have non-autonomous When ACP functionality is added to nodes that have non-autonomous
management plane and/or control plane functions (henceforth called management plane and/or control plane functions (henceforth called
non-autonomous nodes), the ACP instead is best abstracted as a non-autonomous nodes), the ACP instead is best abstracted as a
special Virtual Routing and Forwarding (VRF) instance (or virtual special Virtual Routing and Forwarding (VRF) instance (or virtual
router) and the complete pre-existing non-autonomous management and/ router) and the complete pre-existing non-autonomous management and/
or control plane is considered to be part of the Data-Plane to avoid or control plane is considered to be part of the Data-Plane to avoid
introduction of more complex, new terminology only for this case. introduction of more complex, new terminology only for this case.
Like the forwarding plane for "Data" packets, the non-autonomous Like the forwarding plane for "Data" packets, the non-autonomous
skipping to change at page 8, line 11 skipping to change at page 8, line 11
Signaling Protocol (GRASP - [I-D.ietf-anima-grasp]) runs securely Signaling Protocol (GRASP - [I-D.ietf-anima-grasp]) runs securely
inside the ACP and depends on the ACP as its "security and inside the ACP and depends on the ACP as its "security and
transport substrate". transport substrate".
2. A controller or network management system can use it to securely 2. A controller or network management system can use it to securely
bootstrap network devices in remote locations, even if the (Data- bootstrap network devices in remote locations, even if the (Data-
Plane) network in between is not yet configured; no Data-Plane Plane) network in between is not yet configured; no Data-Plane
dependent bootstrap configuration is required. An example of dependent bootstrap configuration is required. An example of
such a secure bootstrap process is described in such a secure bootstrap process is described in
[I-D.ietf-anima-bootstrapping-keyinfra]. [I-D.ietf-anima-bootstrapping-keyinfra].
3. An operator can use it to access remote devices using protocols 3. An operator can use it to access remote devices using protocols
such as Secure SHell (SSH) or Network Configuration Protocol such as Secure SHell (SSH) or Network Configuration Protocol
(NETCONF) running across the ACP, even if the network is (NETCONF) running across the ACP, even if the network is
misconfigured or not configured. misconfigured or not configured.
This document describes these purposes as use cases for the ACP in This document describes these purposes as use cases for the ACP in
Section 3, it defines the requirements in Section 4. Section 5 gives Section 3, it defines the requirements in Section 4. Section 5 gives
an overview how the ACP is constructed. an overview of how the ACP is constructed.
The normative part of this document starts with Section 6, where the The normative part of this document starts with Section 6, where the
ACP is specified. Section 7 explains how to support ACP on L2 ACP is specified. Section 7 explains how to support ACP on L2
switches (normative). Section 8 explains how non-ACP nodes and switches (normative). Section 8 explains how non-ACP nodes and
networks can be integrated (normative). networks can be integrated (normative).
The remaining sections are non-normative: Section 10 reviews benefits The remaining sections are non-normative: Section 10 reviews benefits
of the ACP (after all the details have been defined), Section 9 of the ACP (after all the details have been defined), Section 9
provides operational recommendations, Appendix A provides additional provides operational recommendations, Appendix A provides additional
explanations and describes additional details or future standard or explanations and describes additional details or future standard or
propriety extensions that were considered not to be appropriate for proprietary extensions that were considered not to be appropriate for
standardization in this document but were considered important to standardization in this document but were considered important to
document. There are no dependencies against Appendix A to build a document. There are no dependencies against Appendix A to build a
complete working and interoperable ACP according to this document. complete working and interoperable ACP according to this document.
The ACP provides secure IPv6 connectivity, therefore it can be used The ACP provides secure IPv6 connectivity, therefore it can be used
not only as the secure connectivity for self-management as required not only as the secure connectivity for self-management as required
for the ACP in [RFC7575], but it can also be used as the secure for the ACP in [RFC7575], but it can also be used as the secure
connectivity for traditional (centralized) management. The ACP can connectivity for traditional (centralized) management. The ACP can
be implemented and operated without any other components of autonomic be implemented and operated without any other components of autonomic
networks, except for the GRASP protocol. ACP relies on per-link DULL networks, except for the GRASP protocol. ACP relies on per-link DULL
GRASP (see Section 6.3) to autodiscover ACP neighbors, and includes GRASP (see Section 6.4) to autodiscover ACP neighbors, and includes
the ACP GRASP instance to provide service discovery for clients of the ACP GRASP instance to provide service discovery for clients of
the ACP (see Section 6.8) including for its own maintenance of ACP the ACP (see Section 6.9) including for its own maintenance of ACP
certificates. certificates.
The document "Using Autonomic Control Plane for Stable Connectivity The document "Using Autonomic Control Plane for Stable Connectivity
of Network OAM" [RFC8368] describes how the ACP alone can be used to of Network OAM" [RFC8368] describes how the ACP alone can be used to
provide secure and stable connectivity for autonomic and non- provide secure and stable connectivity for autonomic and non-
autonomic OAM applications, specifically for the case of current non- autonomic OAM applications, specifically for the case of current non-
autonomic networks/nodes. That document also explains how existing autonomic networks/nodes. That document also explains how existing
management solutions can leverage the ACP in parallel with management solutions can leverage the ACP in parallel with
traditional management models, when to use the ACP and how to traditional management models, when to use the ACP and how to
integrate with potentially IPv4 only OAM backends. integrate with potentially IPv4 only OAM backends.
skipping to change at page 9, line 29 skipping to change at page 9, line 27
1.1. Applicability and Scope 1.1. Applicability and Scope
Please see the following Terminology section (Section 2) for Please see the following Terminology section (Section 2) for
explanations of terms used in this section. explanations of terms used in this section.
The design of the ACP as defined in this document is considered to be The design of the ACP as defined in this document is considered to be
applicable to all types of "professionally managed" networks: Service applicable to all types of "professionally managed" networks: Service
Provider, Local Area Network (LAN), Metro(politan networks), Wide Provider, Local Area Network (LAN), Metro(politan networks), Wide
Area Network (WAN), Enterprise Information Technology (IT) and Area Network (WAN), Enterprise Information Technology (IT) and
->"Operational Technology" () (OT) networks. The ACP can operate ->"Operational Technology" (OT) networks. The ACP can operate
equally on layer 3 equipment and on layer 2 equipment such as bridges equally on layer 3 equipment and on layer 2 equipment such as bridges
(see Section 7). The hop-by-hop authentication, integrity-protection (see Section 7). The hop-by-hop authentication, integrity-protection
and confidentiality mechanism used by the ACP is defined to be and confidentiality mechanism used by the ACP is defined to be
negotiable, therefore it can be extended to environments with negotiable, therefore it can be extended to environments with
different protocol preferences. The minimum implementation different protocol preferences. The minimum implementation
requirements in this document attempt to achieve maximum requirements in this document attempt to achieve maximum
interoperability by requiring support for multiple options depending interoperability by requiring support for multiple options depending
on the type of device: IPsec, see [RFC4301], and datagram Transport on the type of device: IPsec, see [RFC4301], and Datagram Transport
Layer Security (DTLS) version 1.2, see [RFC6347]). Layer Security (DTLS, see Section 6.8.4).
The implementation footprint of the ACP consists of Public Key The implementation footprint of the ACP consists of Public Key
Infrastructure (PKI) code for the ACP certificate, the GRASP Infrastructure (PKI) code for the ACP certificate including
protocol, UDP, TCP and TLS 1.2 ([RFC5246], for security and "Enrollment over Secure Transport (EST, see [RFC7030]), the GRASP
reliability of GRASP), the ACP secure channel protocol used (such as protocol, UDP, TCP and Transport Layer Security (TLS, see
IPsec or DTLS), and an instance of IPv6 packet forwarding and routing Section 6.1), for security and reliability of GRASP and for EST, the
via the Routing Protocol for Low-power and Lossy Networks (RPL), see ACP secure channel protocol used (such as IPsec or DTLS), and an
[RFC6550], that is separate from routing and forwarding for the Data- instance of IPv6 packet forwarding and routing via the Routing
Plane (user traffic). Protocol for Low-power and Lossy Networks (RPL), see [RFC6550], that
is separate from routing and forwarding for the Data-Plane (user
traffic).
The ACP uses only IPv6 to avoid complexity of dual-stack ACP The ACP uses only IPv6 to avoid complexity of dual-stack ACP
operations (IPv6/IPv4). Nevertheless, it can without any changes be operations (IPv6/IPv4). Nevertheless, it can without any changes be
integrated into even otherwise IPv4-only network devices. The Data- integrated into even otherwise IPv4-only network devices. The Data-
Plane itself would not need to change, it could continue to be IPv4 Plane itself would not need to change and it could continue to be
only. For such IPv4 only devices, the IPv6 protocol itself would be IPv4 only. For such IPv4-only devices, the IPv6 protocol itself
additional implementation footprint only used for the ACP. would be additional implementation footprint that is only required
for the ACP.
The protocol choices of the ACP are primarily based on wide use and The protocol choices of the ACP are primarily based on wide use and
support in networks and devices, well understood security properties support in networks and devices, well understood security properties
and required scalability. The ACP design is an attempt to produce and required scalability. The ACP design is an attempt to produce
the lowest risk combination of existing technologies and protocols to the lowest risk combination of existing technologies and protocols to
build a widely applicable operational network management solution. build a widely applicable operational network management solution.
RPL was chosen because it requires a smaller routing table footprint RPL was chosen because it requires a smaller routing table footprint
in large networks compared to other routing protocols with an in large networks compared to other routing protocols with an
autonomically configured single area. The deployment experience of autonomically configured single area. The deployment experience of
skipping to change at page 10, line 28 skipping to change at page 10, line 28
wide deployment experience with RPL. The profile chosen for RPL in wide deployment experience with RPL. The profile chosen for RPL in
the ACP does not leverage any RPL specific forwarding plane features the ACP does not leverage any RPL specific forwarding plane features
(IPv6 extension headers), making its implementation a pure control (IPv6 extension headers), making its implementation a pure control
plane software requirement. plane software requirement.
GRASP is the only completely novel protocol used in the ACP, and this GRASP is the only completely novel protocol used in the ACP, and this
choice was necessary because there is no existing suitable protocol choice was necessary because there is no existing suitable protocol
to provide the necessary functions to the ACP, so GRASP was developed to provide the necessary functions to the ACP, so GRASP was developed
to fill that gap. to fill that gap.
The ACP design can be applicable to (cpu, memory) constrained devices The ACP design can be applicable to devices constrained with respect
and (bitrate, reliability) constrained networks, but this document to cpu and memory, and to networks constrained with respect to
does not attempt to define the most constrained type of devices or bitrate and reliability, but this document does not attempt to define
networks to which the ACP is applicable. RPL and DTLS for ACP secure the most constrained type of devices or networks to which the ACP is
channels are two protocol choices already making ACP more applicable applicable. RPL and DTLS for ACP secure channels are two protocol
to constrained environments. Support for constrained devices in this choices already making ACP more applicable to constrained
specification is opportunistic, but not complete, because the environments. Support for constrained devices in this specification
reliable transport for GRASP (see Section 6.8.2) only specifies TCP/ is opportunistic, but not complete, because the reliable transport
TLS). See Appendix A.9 for discussions about how future standards or for GRASP (see Section 6.9.2) only specifies TCP/TLS. See
Appendix A.9 for discussions about how future standards or
proprietary extensions/variations of the ACP could better meet proprietary extensions/variations of the ACP could better meet
different expectations from those on which the current design is different expectations from those on which the current design is
based including supporting constrained devices better. based including supporting constrained devices better.
2. Acronyms and Terminology (Informative) 2. Acronyms and Terminology (Informative)
[RFC Editor: Please add ACP, BRSKI, GRASP, MASA to https://www.rfc- [RFC Editor: Please add ACP, BRSKI, GRASP, MASA to https://www.rfc-
editor.org/materials/abbrev.expansion.txt.] editor.org/materials/abbrev.expansion.txt.]
[RFC Editor: WG/IETF/IESG review of the terms below asked for [RFC Editor: What is the recommended way to reference a hanging text,
references between these terms when they refer to each other. The e.g.: to a definition in the list of definitions ? Up to -28, this
only option I could find for RFC/XML to point to a hanging text document was using XMLv2 and the only option I could find for RFC/XML
acronym definition that also displays the actual term is the to point to a hanging text was format="title" , which leads to
format="title" version, which leads to references such as '->"ACP references such as '->"ACP certificate" ()', aka: redundant empty
certificate" ()'. I found no reasonable way to eliminate the parenthsis. Many reviewer where concerned about this. I created a
trailing '()' generated by this type of cross references. Can you ticket to ask for an xml2rfc enhancement to avoid this in the future:
please take care of removing these artefacts during editing (after https://trac.tools.ietf.org/tools/xml2rfc/trac/ticket/347. When i
conversion to nroff ?). I also created a ticket to ask for an changed to XMLv3 in version -29, i could get rid of the unnecessary
xml2rfc enhancement to avoid this in the future: () by using format="none", but that format is declared to be
https://trac.tools.ietf.org/tools/xml2rfc/trac/ticket/347.] deprecated in XMLv3. So i am not aware of any working AND "non-
deprecated" option.]
[RFC Editor: Question: Is it possible to change the first occurrences [RFC Editor: Question: Is it possible to change the first occurrences
of [RFCxxxx] references to "rfcxxx title" [RFCxxxx]? the XML2RFC of [RFCxxxx] references to "rfcxxx title" [RFCxxxx]? the XML2RFC
format does not seem to offer such a format, but I did not want to format does not seem to offer such a format, but I did not want to
duplicate 50 first references - one reference for title mentioning duplicate 50 first references - one reference for title mentioning
and one for RFC number.] and one for RFC number.]
This document serves both as a normative specification for how ACP This document serves both as a normative specification for how ACP
nodes have to behave as well as describing requirements, benefits, nodes have to behave as well as describing requirements, benefits,
architecture and operational aspects to explain the context. architecture and operational aspects to explain the context.
Normative sections are labelled "(Normative)" and use Normative sections are labelled "(Normative)" and use BCP 14
[RFC2119]/[RFC8174] keywords. Other sections are labelled keywords. Other sections are labelled "(Informative)" and do not use
"(Informative)" and do not use those normative keywords. those normative keywords.
In the rest of the document we will refer to systems using the ACP as In the rest of the document we will refer to systems using the ACP as
"nodes". Typically such a node is a physical (network equipment) "nodes". Typically such a node is a physical (network equipment)
device, but it can equally be some virtualized system. Therefore, we device, but it can equally be some virtualized system. Therefore, we
do not refer to them as devices unless the context specifically calls do not refer to them as devices unless the context specifically calls
for a physical system. for a physical system.
This document introduces or uses the following terms (sorted This document introduces or uses the following terms (sorted
alphabetically). Terms introduced are explained on first use, so alphabetically). Terms introduced are explained on first use, so
this list is for reference only. this list is for reference only.
skipping to change at page 11, line 41 skipping to change at page 11, line 43
this list is for reference only. this list is for reference only.
ACP: "Autonomic Control Plane". The Autonomic Function as defined ACP: "Autonomic Control Plane". The Autonomic Function as defined
in this document. It provides secure zero-touch (automated) in this document. It provides secure zero-touch (automated)
transitive (network wide) IPv6 connectivity for all nodes in the transitive (network wide) IPv6 connectivity for all nodes in the
same ACP domain as well as a GRASP instance running across this same ACP domain as well as a GRASP instance running across this
ACP IPv6 connectivity. The ACP is primarily meant to be used as a ACP IPv6 connectivity. The ACP is primarily meant to be used as a
component of the ANI to enable Autonomic Networks but it can component of the ANI to enable Autonomic Networks but it can
equally be used in simple ANI networks (with no other Autonomic equally be used in simple ANI networks (with no other Autonomic
Functions) or completely by itself. Functions) or completely by itself.
ACP address: An IPv6 address assigned to the ACP node. It is stored ACP address: An IPv6 address assigned to the ACP node. It is stored
in the acp-node-name of the ->"ACP certificate" (). in the acp-node-name of the ->"ACP certificate".
ACP address range/set: The ACP address may imply a range or set of ACP address range/set: The ACP address may imply a range or set of
addresses that the node can assign for different purposes. This addresses that the node can assign for different purposes. This
address range/set is derived by the node from the format of the address range/set is derived by the node from the format of the
ACP address called the "addressing sub-scheme". ACP address called the "addressing sub-scheme".
ACP connect interface: An interface on an ACP node providing access ACP connect interface: An interface on an ACP node providing access
to the ACP for non ACP capable nodes without using an ACP secure to the ACP for non ACP capable nodes without using an ACP secure
channel. See Section 8.1.1. channel. See Section 8.1.1.
ACP domain: The ACP domain is the set of nodes with ->"ACP ACP domain: The ACP domain is the set of nodes with ->"ACP
certificates" that allow them to authenticate each other as certificates" that allow them to authenticate each other as
members of the ACP domain. See also Section 6.1.3. members of the ACP domain. See also Section 6.2.3.
ACP (ANI/AN) certificate: A [RFC5280] certificate (LDevID) carrying
ACP (ANI/AN) Domain Certificate: A [RFC5280] certificate (LDevID) the acp-node-name which is used by the ACP to learn its address in
carrying the acp-node-name which is used by the ACP to learn its the ACP and to derive and cryptographically assert its membership
address in the ACP and to derive and cryptographically assert its in the ACP domain.
membership in the ACP domain.
ACP acp-node-name field: An information field in the ACP certificate ACP acp-node-name field: An information field in the ACP certificate
in which the ACP relevant information is encoded: the ACP domain in which the ACP relevant information is encoded: the ACP domain
name, the ACP IPv6 address of the node and optional additional name, the ACP IPv6 address of the node and optional additional
role attributes about the node. role attributes about the node.
ACP Loopback interface: The Loopback interface in the ACP Virtual ACP Loopback interface: The Loopback interface in the ACP Virtual
Routing and Forwarding (VRF) that has the ACP address assigned to Routing and Forwarding (VRF) that has the ACP address assigned to
it. See Section 6.12.5.1. it. See Section 6.13.5.1.
ACP network: The ACP network constitutes all the nodes that have ACP network: The ACP network constitutes all the nodes that have
access to the ACP. It is the set of active and transitively access to the ACP. It is the set of active and transitively
connected nodes of an ACP domain plus all nodes that get access to connected nodes of an ACP domain plus all nodes that get access to
the ACP of that domain via ACP edge nodes. the ACP of that domain via ACP edge nodes.
ACP (ULA) prefix(es): The /48 IPv6 address prefixes used across the ACP (ULA) prefix(es): The /48 IPv6 address prefixes used across the
ACP. In the normal/simple case, the ACP has one ULA prefix, see ACP. In the normal/simple case, the ACP has one ULA prefix, see
Section 6.10. The ACP routing table may include multiple ULA Section 6.11. The ACP routing table may include multiple ULA
prefixes if the "rsub" option is used to create addresses from prefixes if the "rsub" option is used to create addresses from
more than one ULA prefix. See Section 6.1.2. The ACP may also more than one ULA prefix. See Section 6.2.2. The ACP may also
include non-ULA prefixes if those are configured on ACP connect include non-ULA prefixes if those are configured on ACP connect
interfaces. See Section 8.1.1. interfaces. See Section 8.1.1.
ACP secure channel: A channel authenticated via ->"ACP certificates" ACP secure channel: A channel authenticated via ->"ACP certificates"
() providing integrity protection and confidentiality through providing integrity protection and confidentiality through
encryption. These are established between (normally) adjacent ACP encryption. These are established between (normally) adjacent ACP
nodes to carry traffic of the ACP VRF securely and isolated from nodes to carry traffic of the ACP VRF securely and isolated from
Data-Plane traffic in-band over the same link/path as the Data- Data-Plane traffic in-band over the same link/path as the Data-
Plane. Plane.
ACP secure channel protocol: The protocol used to build an ACP ACP secure channel protocol: The protocol used to build an ACP
secure channel, e.g., Internet Key Exchange Protocol version 2 secure channel, e.g., Internet Key Exchange Protocol version 2
(IKEv2) with IPsec or Datagram Transport Layer Security (DTLS). (IKEv2) with IPsec or Datagram Transport Layer Security (DTLS).
ACP virtual interface: An interface in the ACP VRF mapped to one or ACP virtual interface: An interface in the ACP VRF mapped to one or
more ACP secure channels. See Section 6.12.5. more ACP secure channels. See Section 6.13.5.
AN "Autonomic Network": A network according to
AN "Autonomic Network": A network according to
[I-D.ietf-anima-reference-model]. Its main components are ANI, [I-D.ietf-anima-reference-model]. Its main components are ANI,
Autonomic Functions and Intent. Autonomic Functions and Intent.
(AN) Domain Name: An FQDN (Fully Qualified Domain Name) in the acp- (AN) Domain Name: An FQDN (Fully Qualified Domain Name) in the acp-
node-name of the Domain Certificate. See Section 6.1.2. node-name of the Domain Certificate. See Section 6.2.2.
ANI (nodes/network): "Autonomic Network Infrastructure". The ANI is ANI (nodes/network): "Autonomic Network Infrastructure". The ANI is
the infrastructure to enable Autonomic Networks. It includes ACP, the infrastructure to enable Autonomic Networks. It includes ACP,
BRSKI and GRASP. Every Autonomic Network includes the ANI, but BRSKI and GRASP. Every Autonomic Network includes the ANI, but
not every ANI network needs to include autonomic functions beyond not every ANI network needs to include autonomic functions beyond
the ANI (nor Intent). An ANI network without further autonomic the ANI (nor Intent). An ANI network without further autonomic
functions can for example support secure zero-touch (automated) functions can for example support secure zero-touch (automated)
bootstrap and stable connectivity for SDN networks - see bootstrap and stable connectivity for SDN networks - see
[RFC8368]. [RFC8368].
ANIMA: "Autonomic Networking Integrated Model and Approach". ACP, ANIMA: "Autonomic Networking Integrated Model and Approach". ACP,
BRSKI and GRASP are specifications of the IETF ANIMA working BRSKI and GRASP are specifications of the IETF ANIMA working
group. group.
ASA: "Autonomic Service Agent". Autonomic software modules running ASA: "Autonomic Service Agent". Autonomic software modules running
on an ANI device. The components making up the ANI (BRSKI, ACP, on an ANI device. The components making up the ANI (BRSKI, ACP,
GRASP) are also described as ASAs. GRASP) are also described as ASAs.
Autonomic Function: A function/service in an Autonomic Network (AN) Autonomic Function: A function/service in an Autonomic Network (AN)
composed of one or more ASA across one or more ANI nodes. composed of one or more ASA across one or more ANI nodes.
BRSKI: "Bootstrapping Remote Secure Key Infrastructures" BRSKI: "Bootstrapping Remote Secure Key Infrastructures"
([I-D.ietf-anima-bootstrapping-keyinfra]. A protocol extending ([I-D.ietf-anima-bootstrapping-keyinfra]. A protocol extending
EST to enable secure zero-touch bootstrap in conjunction with ACP. EST to enable secure zero-touch bootstrap in conjunction with ACP.
ANI nodes use ACP, BRSKI and GRASP. ANI nodes use ACP, BRSKI and GRASP.
CA: "Certification Authority". An entity that issues digital CA: "Certification Authority". An entity that issues digital
certificates. A CA uses its private key to sign the certificates certificates. A CA uses its private key to sign the certificates
it issues, relying parties use the public key in the CA it issues. Relying parties use the public key in the CA
certificate to validate the signature. This signing certificate certificate to validate the signature.
can be considered to be an identifier of the CA, so the term CA is
also loosely used to refer to the certificate used by the CA for
signing.
CRL: "Certificate Revocation List". A list of revoked certificates. CRL: "Certificate Revocation List". A list of revoked certificates.
Required to revoke certificates before their lifetime expires. Required to revoke certificates before their lifetime expires.
Data-Plane: The counterpoint to the ACP VRF in an ACP node: Data-Plane: The counterpoint to the ACP VRF in an ACP node:
forwarding of user traffic and in non-autonomous nodes/networks forwarding of user traffic and in non-autonomous nodes/networks
also any non-autonomous control and/or management plane functions. also any non-autonomous control and/or management plane functions.
In a fully Autonomic Network node, the Data-Plane is managed In a fully Autonomic Network node, the Data-Plane is managed
autonomically via Autonomic Functions and Intent. See Section 1 autonomically via Autonomic Functions and Intent. See Section 1
for more detailed explanations. for more detailed explanations.
device: A physical system, or physical node. device: A physical system, or physical node.
Enrollment: The process through which a node authenticates itself to Enrollment: The process through which a node authenticates itself to
a network with an initial identity, which is often called IDevID a network with an initial identity, which is often called IDevID
certificate, and acquires from the network a network specific certificate, and acquires from the network a network specific
identity, which is often called LDevID certificate, and identity, which is often called LDevID certificate, and
certificates of one or more Trust Anchor(s). In the ACP, the certificates of one or more Trust Anchor(s). In the ACP, the
LDevID certificate is called the ACP certificate. LDevID certificate is called the ACP certificate.
EST: "Enrollment over Secure Transport" ([RFC7030]). IETF standard- EST: "Enrollment over Secure Transport" ([RFC7030]). IETF standard-
track protocol for enrollment of a node with an LDevID track protocol for enrollment of a node with an LDevID
certificate. BRSKI is based on EST. certificate. BRSKI is based on EST.
GRASP: "Generic Autonomic Signaling Protocol". An extensible GRASP: "Generic Autonomic Signaling Protocol". An extensible
signaling protocol required by the ACP for ACP neighbor discovery. signaling protocol required by the ACP for ACP neighbor discovery.
The ACP also provides the "security and transport substrate" for The ACP also provides the "security and transport substrate" for
the "ACP instance of GRASP". This instance of GRASP runs across the "ACP instance of GRASP". This instance of GRASP runs across
the ACP secure channels to support BRSKI and other NOC/OAM or the ACP secure channels to support BRSKI and other NOC/OAM or
Autonomic Functions. See [I-D.ietf-anima-grasp]. Autonomic Functions. See [I-D.ietf-anima-grasp].
IDevID: An "Initial Device IDentity" X.509 certificate installed by IDevID: An "Initial Device IDentity" X.509 certificate installed by
the vendor on new equipment. Contains information that the vendor on new equipment. Contains information that
establishes the identity of the node in the context of its vendor/ establishes the identity of the node in the context of its vendor/
manufacturer such as device model/type and serial number. See manufacturer such as device model/type and serial number. See
[AR8021]. The IDevID certificate cannot be used as a node [AR8021]. The IDevID certificate cannot be used as a node
identifier for the ACP because they are not provisioned by the identifier for the ACP because they are not provisioned by the
owner of the network, so they can not directly indicate an ACP owner of the network, so they can not directly indicate an ACP
domain they belong to. domain they belong to.
in-band (management/signaling): In-band management traffic and/or in-band (management/signaling): In-band management traffic and/or
control plane signaling uses the same network resources such as control plane signaling uses the same network resources such as
routers/switches and network links that it manages/controls. In- routers/switches and network links that it manages/controls. In-
band is the standard management and signaling mechanism in IP band is the standard management and signaling mechanism in IP
networks. Compared to ->"out-of-band" () it requires no networks. Compared to ->"out-of-band" it requires no additional
additional physical resources, but introduces potentially circular physical resources, but introduces potentially circular
dependencies for its correct operations. See ->"introduction" dependencies for its correct operations. See ->"introduction".
(Introduction (Informative)).
Intent: Policy language of an autonomic network according to Intent: Policy language of an autonomic network according to
[I-D.ietf-anima-reference-model]. [I-D.ietf-anima-reference-model].
Loopback interface: See ->"ACP Loopback interface".
Loopback interface: See ->"ACP Loopback interface" ().
LDevID: A "Local Device IDentity" is an X.509 certificate installed LDevID: A "Local Device IDentity" is an X.509 certificate installed
during "enrollment". The Domain Certificate used by the ACP is an during "enrollment". The Domain Certificate used by the ACP is an
LDevID certificate. See [AR8021]. LDevID certificate. See [AR8021].
Management: Used in this document as another word for ->"OAM".
Management: Used in this document as another word for ->"OAM" ().
MASA (service): "Manufacturer Authorized Signing Authority". A MASA (service): "Manufacturer Authorized Signing Authority". A
vendor/manufacturer or delegated cloud service on the Internet vendor/manufacturer or delegated cloud service on the Internet
used as part of the BRSKI protocol. used as part of the BRSKI protocol.
MIC: "Manufacturer Installed Certificate". This is another word to MIC: "Manufacturer Installed Certificate". This is another word to
describe an IDevID in referenced materials. This term is not used describe an IDevID in referenced materials. This term is not used
in this document. in this document.
native interface: Interfaces existing on a node without native interface: Interfaces existing on a node without
configuration of the already running node. On physical nodes configuration of the already running node. On physical nodes
these are usually physical interfaces. On virtual nodes their these are usually physical interfaces; on virtual nodes their
equivalent. equivalent.
NOC: Network Operations Center. NOC: Network Operations Center.
node: A system supporting the ACP according to this document. Can node: A system supporting the ACP according to this document. Can
be virtual or physical. Physical nodes are called devices. be virtual or physical. Physical nodes are called devices.
Node-ID: The identifier of an ACP node inside that ACP. It is the Node-ID: The identifier of an ACP node inside that ACP. It is the
last 64 (see Section 6.10.3) or 78-bits (see Section 6.10.5) of last 64 (see Section 6.11.3) or 78-bits (see Section 6.11.5) of
the ACP address. the ACP address.
OAM: Operations, Administration and Management. Includes Network OAM: Operations, Administration and Management. Includes Network
Monitoring. Monitoring.
Operational Technology (OT): https://en.wikipedia.org/wiki/
Operational Technology (OT): "https://en.wikipedia.org/wiki/ Operational_Technology: "The hardware and software dedicated to
Operational_Technology" [1]: "The hardware and software dedicated detecting or causing changes in physical processes through direct
to detecting or causing changes in physical processes through monitoring and/or control of physical devices such as valves,
direct monitoring and/or control of physical devices such as pumps, etc.". OT networks are today in most cases well separated
valves, pumps, etc.". OT networks are today in most cases well from Information Technology (IT) networks.
separated from Information Technology (IT) networks.
out-of-band (management) network: An out-of-band network is a out-of-band (management) network: An out-of-band network is a
secondary network used to manage a primary network. The equipment secondary network used to manage a primary network. The equipment
of the primary network is connected to the out-of-band network via of the primary network is connected to the out-of-band network via
dedicated management ports on the primary network equipment. dedicated management ports on the primary network equipment.
Serial (console) management ports were historically most common, Serial (console) management ports were historically most common,
higher end network equipment now also has ethernet ports dedicated higher end network equipment now also has ethernet ports dedicated
only for management. An out-of-band network provides management only for management. An out-of-band network provides management
access to the primary network independent of the configuration access to the primary network independent of the configuration
state of the primary network. See ->"introduction" state of the primary network. See ->"Introduction"
(Introduction (Informative))
(virtual) out-of-band network: The ACP can be called a virtual out- (virtual) out-of-band network: The ACP can be called a virtual out-
of-band network for management and control because it attempts to of-band network for management and control because it attempts to
provide the benefits of a (physical) ->"out-of-band network" () provide the benefits of a (physical) ->"out-of-band network" even
even though it is physically carried ->"in-band" (). See though it is physically carried ->"in-band". See
->"introduction" (Introduction (Informative)). ->"introduction".
root CA: "root Certification Authority". A ->"CA" for which the
root CA: "root Certification Authority". A ->"CA" () for which the
root CA Key update procedures of [RFC7030], Section 4.4 can be root CA Key update procedures of [RFC7030], Section 4.4 can be
applied. applied.
RPL: "IPv6 Routing Protocol for Low-Power and Lossy Networks". The RPL: "IPv6 Routing Protocol for Low-Power and Lossy Networks". The
routing protocol used in the ACP. See [RFC6550]. routing protocol used in the ACP. See [RFC6550].
(ACP/ANI/BRSKI) Registrar: An ACP registrar is an entity (software (ACP/ANI/BRSKI) Registrar: An ACP registrar is an entity (software
and/or person) that is orchestrating the enrollment of ACP nodes and/or person) that is orchestrating the enrollment of ACP nodes
with the ACP certificate. ANI nodes use BRSKI, so ANI registrars with the ACP certificate. ANI nodes use BRSKI, so ANI registrars
are also called BRSKI registrars. For non-ANI ACP nodes, the are also called BRSKI registrars. For non-ANI ACP nodes, the
registrar mechanisms are undefined by this document. See registrar mechanisms are undefined by this document. See
Section 6.10.7. Renewal and other maintenance (such as Section 6.11.7. Renewal and other maintenance (such as
revocation) of ACP certificates may be performed by other entities revocation) of ACP certificates may be performed by other entities
than registrars. EST must be supported for ACP certificate than registrars. EST must be supported for ACP certificate
renewal (see Section 6.1.5). BRSKI is an extension of EST, so renewal (see Section 6.2.5). BRSKI is an extension of EST, so
ANI/BRSKI registrars can easily support ACP domain certificate ANI/BRSKI registrars can easily support ACP domain certificate
renewal in addition to initial enrollment. renewal in addition to initial enrollment.
RPI: "RPL Packet Information". Network extension headers for use RPI: "RPL Packet Information". Network extension headers for use
with the ->"RPL" () routing protocols. Not used with RPL in the with the ->"RPL" routing protocols. Not used with RPL in the ACP.
ACP. See Section 6.11.1.13. See Section 6.12.1.13.
RPL: "Routing Protocol for Low-Power and Lossy Networks". The RPL: "Routing Protocol for Low-Power and Lossy Networks". The
routing protocol used in the ACP. See Section 6.11. routing protocol used in the ACP. See Section 6.12.
sUDI: "secured Unique Device Identifier". This is another word to sUDI: "secured Unique Device Identifier". This is another word to
describe an IDevID in referenced material. This term is not used describe an IDevID in referenced material. This term is not used
in this document. in this document.
TA: "Trust Anchor". A Trust Anchor is an entity that is trusted for TA: "Trust Anchor". A Trust Anchor is an entity that is trusted for
the purpose of certificate validation. Trust Anchor Information the purpose of certificate validation. Trust Anchor Information
such as self-signed certificate(s) of the Trust Anchor is such as self-signed certificate(s) of the Trust Anchor is
configured into the ACP node as part of Enrollment. See configured into the ACP node as part of Enrollment. See
[RFC5280], Section 6.1.1. [RFC5280], Section 6.1.1.
UDI: "Unique Device Identifier". In the context of this document UDI: "Unique Device Identifier". In the context of this document
unsecured identity information of a node typically consisting of unsecured identity information of a node typically consisting of
at least device model/type and serial number, often in a vendor at least device model/type and serial number, often in a vendor
specific format. See sUDI and LDevID. specific format. See sUDI and LDevID.
ULA: (Global ID prefix) A "Unique Local Address" (ULA) is an IPv6 ULA: (Global ID prefix) A "Unique Local Address" (ULA) is an IPv6
address in the block fc00::/7, defined in [RFC4193]. It is the address in the block fc00::/7, defined in [RFC4193]. It is often
approximate IPv6 counterpart of the IPv4 private address thought of as the approximate IPv6 counterpart of the IPv4 private
([RFC1918]). The ULA Global ID prefix are the first 48-bits of a address ([RFC1918]). There are important differences though that
ULA address. In this document it is abbreviated as "ULA prefix". are beneficial for and exploited by the ACP, such as the ULA
Global ID prefix, which are the first 48-bits of a ULA address.
In this document it is abbreviated as "ULA prefix".
(ACP) VRF: The ACP is modeled in this document as a "Virtual Routing (ACP) VRF: The ACP is modeled in this document as a "Virtual Routing
and Forwarding" instance (VRF). This means that it is based on a and Forwarding" instance (VRF). This means that it is based on a
"virtual router" consisting of a separate IPv6 forwarding table to "virtual router" consisting of a separate IPv6 forwarding table to
which the ACP virtual interfaces are attached and an associated which the ACP virtual interfaces are attached and an associated
IPv6 routing table separate from the Data-Plane. Unlike the VRFs IPv6 routing table separate from the Data-Plane. Unlike the VRFs
on MPLS/VPN-PE ([RFC4364]) or LISP XTR ([RFC6830]), the ACP VRF on MPLS/VPN-PE ([RFC4364]) or LISP XTR ([RFC6830]), the ACP VRF
does not have any special "core facing" functionality or routing/ does not have any special "core facing" functionality or routing/
mapping protocols shared across multiple VRFs. In vendor products mapping protocols shared across multiple VRFs. In vendor products
a VRF such as the ACP-VRF may also be referred to as a so called a VRF such as the ACP-VRF may also be referred to as a so called
VRF-lite. VRF-lite.
skipping to change at page 17, line 21 skipping to change at page 16, line 20
(ACP) VRF: The ACP is modeled in this document as a "Virtual Routing (ACP) VRF: The ACP is modeled in this document as a "Virtual Routing
and Forwarding" instance (VRF). This means that it is based on a and Forwarding" instance (VRF). This means that it is based on a
"virtual router" consisting of a separate IPv6 forwarding table to "virtual router" consisting of a separate IPv6 forwarding table to
which the ACP virtual interfaces are attached and an associated which the ACP virtual interfaces are attached and an associated
IPv6 routing table separate from the Data-Plane. Unlike the VRFs IPv6 routing table separate from the Data-Plane. Unlike the VRFs
on MPLS/VPN-PE ([RFC4364]) or LISP XTR ([RFC6830]), the ACP VRF on MPLS/VPN-PE ([RFC4364]) or LISP XTR ([RFC6830]), the ACP VRF
does not have any special "core facing" functionality or routing/ does not have any special "core facing" functionality or routing/
mapping protocols shared across multiple VRFs. In vendor products mapping protocols shared across multiple VRFs. In vendor products
a VRF such as the ACP-VRF may also be referred to as a so called a VRF such as the ACP-VRF may also be referred to as a so called
VRF-lite. VRF-lite.
(ACP) Zone: An ACP zone is a set of ACP nodes using the same zone (ACP) Zone: An ACP zone is a set of ACP nodes using the same zone
field value in their ACP address according to Section 6.10.3. field value in their ACP address according to Section 6.11.3.
Zones are a mechanism to support structured addressing of ACP Zones are a mechanism to support structured addressing of ACP
addresses within the same /48-bit ULA prefix. addresses within the same /48-bit ULA prefix.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119],[RFC8174] when, and only when, they appear in all 14 [RFC2119],[RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Use Cases for an Autonomic Control Plane (Informative) 3. Use Cases for an Autonomic Control Plane (Informative)
skipping to change at page 19, line 15 skipping to change at page 18, line 29
or mask changes, routing changes, or security policies. Today such or mask changes, routing changes, or security policies. Today such
changes require precise hop-by-hop planning. changes require precise hop-by-hop planning.
Note that specific control plane functions for the Data-Plane often Note that specific control plane functions for the Data-Plane often
want to depend on forwarding of their packets via the Data-Plane: want to depend on forwarding of their packets via the Data-Plane:
Aliveness and routing protocol signaling packets across the Data- Aliveness and routing protocol signaling packets across the Data-
Plane to verify reachability across the Data-Plane, using IPv4 Plane to verify reachability across the Data-Plane, using IPv4
signaling packets for IPv4 routing vs. IPv6 signaling packets for signaling packets for IPv4 routing vs. IPv6 signaling packets for
IPv6 routing. IPv6 routing.
Assuming appropriate implementation (see Section 6.12.2 for more Assuming appropriate implementation (see Section 6.13.2 for more
details), the ACP provides reachability that is independent of the details), the ACP provides reachability that is independent of the
Data-Plane. This allows the control plane and OAM plane to operate Data-Plane. This allows the control plane and OAM plane to operate
more robustly: more robustly:
o For management plane protocols, the ACP provides the functionality * For management plane protocols, the ACP provides the functionality
of a Virtual out-of-band (VooB) channel, by providing connectivity of a Virtual out-of-band (VooB) channel, by providing connectivity
to all nodes regardless of their Data-Plane configuration, routing to all nodes regardless of their Data-Plane configuration, routing
and forwarding tables. and forwarding tables.
* For control plane protocols, the ACP allows their operation even
o For control plane protocols, the ACP allows their operation even
when the Data-Plane is temporarily faulty, or during transitional when the Data-Plane is temporarily faulty, or during transitional
events, such as routing changes, which may affect the control events, such as routing changes, which may affect the control
plane at least temporarily. This is specifically important for plane at least temporarily. This is specifically important for
autonomic service agents, which could affect Data-Plane autonomic service agents, which could affect Data-Plane
connectivity. connectivity.
The document "Using Autonomic Control Plane for Stable Connectivity The document "Using Autonomic Control Plane for Stable Connectivity
of Network OAM" [RFC8368] explains this use case for the ACP in of Network OAM" [RFC8368] explains this use case for the ACP in
significantly more detail and explains how the ACP can be used in significantly more detail and explains how the ACP can be used in
practical network operations. practical network operations.
skipping to change at page 19, line 48 skipping to change at page 19, line 16
The following requirements were identified for the design of the ACP The following requirements were identified for the design of the ACP
based on the above use-cases (Section 3). These requirements are based on the above use-cases (Section 3). These requirements are
informative. The ACP as specified in the normative parts of this informative. The ACP as specified in the normative parts of this
document is meeting or exceeding these use-case requirements: document is meeting or exceeding these use-case requirements:
ACP1: The ACP should provide robust connectivity: As far as ACP1: The ACP should provide robust connectivity: As far as
possible, it should be independent of configured addressing, possible, it should be independent of configured addressing,
configuration and routing. Requirements 2 and 3 build on this configuration and routing. Requirements 2 and 3 build on this
requirement, but also have value on their own. requirement, but also have value on their own.
ACP2: The ACP must have a separate address space from the Data- ACP2: The ACP must have a separate address space from the Data-
Plane. Reason: traceability, debug-ability, separation from Plane. Reason: traceability, debug-ability, separation from
Data-Plane, infrastructure security (filtering based on known Data-Plane, infrastructure security (filtering based on known
address space). address space).
ACP3: The ACP must use autonomically managed address space. Reason: ACP3: The ACP must use autonomically managed address space. Reason:
easy bootstrap and setup ("autonomic"); robustness (admin easy bootstrap and setup ("autonomic"); robustness (admin
cannot break network easily). This document uses Unique Local cannot break network easily). This document uses Unique Local
Addresses (ULA) for this purpose, see [RFC4193]. Addresses (ULA) for this purpose, see [RFC4193].
ACP4: The ACP must be generic, that is it must be usable by all the ACP4: The ACP must be generic, that is it must be usable by all the
functions and protocols of the ANI. Clients of the ACP must functions and protocols of the ANI. Clients of the ACP must
not be tied to a particular application or transport protocol. not be tied to a particular application or transport protocol.
ACP5: The ACP must provide security: Messages coming through the ACP ACP5: The ACP must provide security: Messages coming through the ACP
must be authenticated to be from a trusted node, and should must be authenticated to be from a trusted node, and it is
(very strong should) be encrypted. very strongly > recommended that they be encrypted.
Explanation for ACP4: In a fully autonomic network (AN), newly Explanation for ACP4: In a fully autonomic network (AN), newly
written ASA could potentially all communicate exclusively via GRASP written ASAs could potentially all communicate exclusively via GRASP
with each other, and if that was assumed to be the only requirement with each other, and if that was assumed to be the only requirement
against the ACP, it would not need to provide IPv6 layer connectivity against the ACP, it would not need to provide IPv6 layer connectivity
between nodes, but only GRASP connectivity. Nevertheless, because between nodes, but only GRASP connectivity. Nevertheless, because
ACP also intends to support non-AN networks, it is crucial to support ACP also intends to support non-AN networks, it is crucial to support
IPv6 layer connectivity across the ACP to support any transport and IPv6 layer connectivity across the ACP to support any transport and
application layer protocols. application layer protocols.
The ACP operates hop-by-hop, because this interaction can be built on The ACP operates hop-by-hop, because this interaction can be built on
IPv6 link local addressing, which is autonomic, and has no dependency IPv6 link local addressing, which is autonomic, and has no dependency
on configuration (requirement 1). It may be necessary to have ACP on configuration (requirement 1). It may be necessary to have ACP
connectivity across non-ACP nodes, for example to link ACP nodes over connectivity across non-ACP nodes, for example to link ACP nodes over
the general Internet. This is possible, but introduces a dependency the general Internet. This is possible, but introduces a dependency
against stable/resilient routing over the non-ACP hops (see against stable/resilient routing over the non-ACP hops (see
Section 8.2). Section 8.2).
5. Overview (Informative) 5. Overview (Informative)
When a node has an ACP certificate (see Section 6.1.1) and is enabled When a node has an ACP certificate (see Section 6.2.1) and is enabled
to bring up the ACP (see Section 9.3.5), it will create its ACP to bring up the ACP (see Section 9.3.5), it will create its ACP
without any configuration as follows. For details, see Section 6 and without any configuration as follows. For details, see Section 6 and
further sections: further sections:
1. The node creates a VRF instance, or a similar virtual context for 1. The node creates a VRF instance, or a similar virtual context for
the ACP. the ACP.
2. The node assigns its ULA IPv6 address (prefix) (see Section 6.11
2. The node assigns its ULA IPv6 address (prefix) (see Section 6.10 which is learned from the acp-node-name (see Section 6.2.2) of
which is learned from the acp-node-name (see Section 6.1.2) of its ACP certificate (see Section 6.2.1) to an ACP loopback
its ACP certificate (see Section 6.1.1) to an ACP loopback interface (see Section 6.11) and connects this interface into the
interface (see Section 6.10) and connects this interface into the
ACP VRF. ACP VRF.
3. The node establishes a list of candidate peer adjacencies and 3. The node establishes a list of candidate peer adjacencies and
candidate channel types to try for the adjacency. This is candidate channel types to try for the adjacency. This is
automatic for all candidate link-local adjacencies, see automatic for all candidate link-local adjacencies, see
Section 6.3 across all native interfaces (see Section 9.3.4). If Section 6.4 across all native interfaces (see Section 9.3.4). If
a candidate peer is discovered via multiple interfaces, this will a candidate peer is discovered via multiple interfaces, this will
result in one adjacency per interface. If the ACP node has result in one adjacency per interface. If the ACP node has
multiple interfaces connecting to the same subnet across which it multiple interfaces connecting to the same subnet across which it
is also operating as an L2 switch in the Data-Plane, it employs is also operating as an L2 switch in the Data-Plane, it employs
methods for ACP with L2 switching, see Section 7. methods for ACP with L2 switching, see Section 7.
4. For each entry in the candidate adjacency list, the node 4. For each entry in the candidate adjacency list, the node
negotiates a secure tunnel using the candidate channel types. negotiates a secure tunnel using the candidate channel types.
See Section 6.5. See Section 6.6.
5. The node authenticates the peer node during secure channel setup 5. The node authenticates the peer node during secure channel setup
and authorizes it to become part of the ACP according to and authorizes it to become part of the ACP according to
Section 6.1.3. Section 6.2.3.
6. Unsuccessful authentication of a candidate peer results in
6. Each successfully established secure channel is mapped into an throttled connection retries for as long as the candidate peer is
discoverable. See Section 6.7.
7. Each successfully established secure channel is mapped into an
ACP virtual interface, which is placed into the ACP VRF. See ACP virtual interface, which is placed into the ACP VRF. See
Section 6.12.5.2. Section 6.13.5.2.
8. Each node runs a lightweight routing protocol, see Section 6.12,
7. Each node runs a lightweight routing protocol, see Section 6.11,
to announce reachability of the ACP loopback address (or prefix) to announce reachability of the ACP loopback address (or prefix)
across the ACP. across the ACP.
9. This completes the creation of the ACP with hop-by-hop secure
8. This completes the creation of the ACP with hop-by-hop secure
tunnels, auto-addressing and auto-routing. The node is now an tunnels, auto-addressing and auto-routing. The node is now an
ACP node with a running ACP. ACP node with a running ACP.
Note: Note:
o None of the above operations (except the following explicit * None of the above operations (except the following explicit
configured ones) are reflected in the configuration of the node. configured ones) are reflected in the configuration of the node.
* Non-ACP NMS ("Network Management Systems") or SDN controllers have
o Non-ACP NMS ("Network Management Systems") or SDN controllers have
to be explicitly configured for connection into the ACP. to be explicitly configured for connection into the ACP.
o Additional candidate peer adjacencies for ACP connections across * Additional candidate peer adjacencies for ACP connections across
non-ACP Layer-3 clouds requires explicit configuration. See non-ACP Layer-3 clouds requires explicit configuration. See
Section 8.2. Section 8.2.
The following figure illustrates the ACP. The following figure illustrates the ACP.
ACP node 1 ACP node 2 ACP node 1 ACP node 2
................... ................... ................... ...................
secure . . secure . . secure secure . . secure . . secure
channel: +-----------+ : channel : +-----------+ : channel channel: +-----------+ : channel : +-----------+ : channel
..--------| ACP VRF |---------------------| ACP VRF |---------.. ..--------| ACP VRF |---------------------| ACP VRF |---------..
skipping to change at page 22, line 37 skipping to change at page 21, line 43
routing problems. routing problems.
6. Self-Creation of an Autonomic Control Plane (ACP) (Normative) 6. Self-Creation of an Autonomic Control Plane (ACP) (Normative)
This section specifies the components and steps to set up an ACP. This section specifies the components and steps to set up an ACP.
The ACP is automatically "self-creating", which makes it The ACP is automatically "self-creating", which makes it
"indestructible" against most changes to the Data-Plane, including "indestructible" against most changes to the Data-Plane, including
misconfigurations of routing, addressing, NAT, firewall or any other misconfigurations of routing, addressing, NAT, firewall or any other
traffic policy filters that inadvertently or otherwise unavoidably traffic policy filters that inadvertently or otherwise unavoidably
would also impact the management plane traffic, such as the actual would also impact the management plane traffic, such as the actual
operator CLI session or controller NetConf session through which the operator CLI session or controller NETCONF session through which the
configuration changes to the Data-Plane are executed. configuration changes to the Data-Plane are executed.
Physical misconfiguration of wiring between ACP nodes will also not Physical misconfiguration of wiring between ACP nodes will also not
break the ACP: As long as there is a transitive physical path between break the ACP: As long as there is a transitive physical path between
ACP nodes, the ACP should be able to recover given that it ACP nodes, the ACP should be able to recover given that it
automatically operates across all interfaces of the ACP nodes and automatically operates across all interfaces of the ACP nodes and
automatically determines paths between them. automatically determines paths between them.
Attacks against the network via incorrect routing or addressing Attacks against the network via incorrect routing or addressing
information for the Data-Plane will not impact the ACP. Even information for the Data-Plane will not impact the ACP. Even
impaired ACP nodes will have a significantly reduced attack surface impaired ACP nodes will have a significantly reduced attack surface
against malicious misconfiguration because only very limited ACP or against malicious misconfiguration because only very limited ACP or
interface up/down configuration can affect the ACP, and pending on interface up/down configuration can affect the ACP, and pending on
their specific designs these type of attacks could also be their specific designs these type of attacks could also be
eliminated. See more in Section 9.3 and Section 11. eliminated. See more in Section 9.3 and Section 11.
An ACP node can be a router, switch, controller, NMS host, or any An ACP node can be a router, switch, controller, NMS host, or any
other IPv6 capable node. Initially, it MUST have its ACP other IPv6 capable node. Initially, it MUST have its ACP
certificate, as well as an (empty) ACP Adjacency Table (described in certificate, as well as an (empty) ACP Adjacency Table (described in
Section 6.2). It then can start to discover ACP neighbors and build Section 6.3). It then can start to discover ACP neighbors and build
the ACP. This is described step by step in the following sections: the ACP. This is described step by step in the following sections:
6.1. ACP Domain, Certificate and Network 6.1. Requirements for use of Transport Layer Security (TLS)
The following requirements apply to TLS required or used by ACP
components. Applicable ACP components include ACP certificate
maintenance via EST, see Section 6.2.5, TLS connections for
Certificate Revocation List (CRL) Distribution Point (CRLDP) or
Online Certificate Status Protocol (OCSP) responder (if used, see
Section 6.2.3) and ACP GRASP (see Section 6.9.2). On ANI nodes these
requirements also apply to BRSKI.
TLS MUST comply with [RFC7525] except that TLS 1.2 ([RFC5246]) is
REQUIRED and that older versions of TLS MUST NOT be used. TLS 1.3
([RFC8446]) SHOULD be supported. The choice for TLS 1.2 as the
lowest common denominator for the ACP is based on current expected
most likely availability across the wide range of candidate ACP node
types, potentially with non-agile operating system TCP/IP stacks.
TLS MUST offer TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 and
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 and MUST NOT offer options
with less than 256 bit symmetric key strength or hash strength of
less than SHA384. When TLS 1.3 is supported, TLS_AES_256_GCM_SHA384
MUST be offered and TLS_CHACHA20_POLY1305_SHA256 MAY be offered.
TLS MUST also include the "Supported Elliptic Curves" extension, it
MUST support the NIST P-256 (secp256r1(22)) and P-384 (secp384r1(24))
curves [RFC4492]. In addition, TLS clients SHOULD send an
ec_point_formats extension with a single element, "uncompressed".
6.2. ACP Domain, Certificate and Network
The ACP relies on group security. An ACP domain is a group of nodes The ACP relies on group security. An ACP domain is a group of nodes
that trust each other to participate in ACP operations such as that trust each other to participate in ACP operations such as
creating ACP secure channels in an autonomous peer-to-peer fashion creating ACP secure channels in an autonomous peer-to-peer fashion
between ACP domain members via protocols such as IPsec. To between ACP domain members via protocols such as IPsec. To
authenticate and authorize another ACP member node with access to the authenticate and authorize another ACP member node with access to the
ACP Domain, each ACP member requires keying material: An ACP node ACP Domain, each ACP member requires keying material: An ACP node
MUST have a Local Device IDentity (LDevID) certificate, henceforth MUST have a Local Device IDentity (LDevID) certificate, henceforth
called the ACP certificate and information about one or more Trust called the ACP certificate and information about one or more Trust
Anchor (TA) as required for the ACP domain membership check Anchor (TA) as required for the ACP domain membership check
(Section 6.1.3). (Section 6.2.3).
Manual keying via shared secrets is not usable for an ACP domain Manual keying via shared secrets is not usable for an ACP domain
because it would require a single shared secret across all current because it would require a single shared secret across all current
and future ACP domain members to meet the expectation of autonomous, and future ACP domain members to meet the expectation of autonomous,
peer-to-peer establishment of ACP secure channels between any ACP peer-to-peer establishment of ACP secure channels between any ACP
domain members. Such a single shared secret would be an inacceptable domain members. Such a single shared secret would be an inacceptable
security weakness. Asymmetric keying material (public keys) without security weakness. Asymmetric keying material (public keys) without
certificates does not provide the mechanisms to authenticate ACP certificates does not provide the mechanisms to authenticate ACP
domain membership in an autonomous, peer-to-peer fashion for current domain membership in an autonomous, peer-to-peer fashion for current
and future ACP domain members. and future ACP domain members.
The LDevID certificate is called the ACP certificate, the TA is the The LDevID certificate is called the ACP certificate. The TA is the
Certification Authority (CA) root certificate of the ACP domain. Certification Authority (CA) root certificate of the ACP domain.
The ACP does not mandate specific mechanisms by which this keying The ACP does not mandate specific mechanisms by which this keying
material is provisioned into the ACP node. It only requires the material is provisioned into the ACP node. It only requires the
certificate to comply with Section 6.1.1, specifically to have the certificate to comply with Section 6.2.1, specifically to have the
acp-node-name as specified in Section 6.1.2 in its domain certificate acp-node-name as specified in Section 6.2.2 in its domain certificate
as well as those of candidate ACP peers. See Appendix A.2 for more as well as those of candidate ACP peers. See Appendix A.2 for more
information about enrollment or provisioning options. information about enrollment or provisioning options.
This document uses the term ACP in many places where the Autonomic This document uses the term ACP in many places where the Autonomic
Networking reference documents [RFC7575] and Networking reference documents [RFC7575] and
[I-D.ietf-anima-reference-model] use the word autonomic. This is [I-D.ietf-anima-reference-model] use the word autonomic. This is
done because those reference documents consider (only) fully done because those reference documents consider (only) fully
autonomic networks and nodes, but support of ACP does not require autonomic networks and nodes, but support of ACP does not require
support for other components of autonomic networks except for relying support for other components of autonomic networks except for relying
on GRASP and providing security and transport for GRASP. Therefore on GRASP and providing security and transport for GRASP. Therefore
skipping to change at page 24, line 16 skipping to change at page 24, line 10
autonomic nodes. ACP nodes do not need to be fully autonomic, but autonomic nodes. ACP nodes do not need to be fully autonomic, but
when they are, then the ACP domain is an autonomic domain. Likewise, when they are, then the ACP domain is an autonomic domain. Likewise,
[I-D.ietf-anima-reference-model] defines the term "Domain [I-D.ietf-anima-reference-model] defines the term "Domain
Certificate" as the certificate used in an autonomic domain. The ACP Certificate" as the certificate used in an autonomic domain. The ACP
certificate is that domain certificate when ACP nodes are (fully) certificate is that domain certificate when ACP nodes are (fully)
autonomic nodes. Finally, this document uses the term ACP network to autonomic nodes. Finally, this document uses the term ACP network to
refer to the network created by active ACP nodes in an ACP domain. refer to the network created by active ACP nodes in an ACP domain.
The ACP network itself can extend beyond ACP nodes through the The ACP network itself can extend beyond ACP nodes through the
mechanisms described in Section 8.1. mechanisms described in Section 8.1.
6.1.1. ACP Certificates 6.2.1. ACP Certificates
ACP certificates MUST be [RFC5280] compliant X.509 v3 ([X.509]) ACP certificates MUST be [RFC5280] compliant X.509 v3 ([X.509])
certificates. certificates.
ACP nodes MUST support handling ACP certificates, TA certificates and ACP nodes MUST support handling ACP certificates, TA certificates and
certificate chain certificates (henceforth just called certificates certificate chain certificates (henceforth just called certificates
in this section) with RSA public keys and certificates with Elliptic in this section) with RSA public keys and certificates with Elliptic
Curve (ECC) public keys. Curve (ECC) public keys.
ACP nodes MUST NOT support certificates with RSA public keys of less ACP nodes MUST NOT support certificates with RSA public keys of less
than 2048 bit modulus or curves with group order of less than 256 than 2048 bit modulus or curves with group order of less than 256
bit. They MUST support certificates with RSA public keys with 2048 bit. They MUST support certificates with RSA public keys with 2048
bit modulus and MAY support longer RSA keys. They MUST support bit modulus and MAY support longer RSA keys. They MUST support
certificates with ECC public keys using NIST P-256 curves and SHOULD certificates with ECC public keys using NIST P-256 curves and SHOULD
support P-384 and P-521 curves. support P-384 and P-521 curves.
ACP nodes MUST support SHA-256 and SHOULD support SHA-384, SHA-512 ACP nodes MUST NOT support certificates with RSA public keys whose
signatures for certificates with RSA key and the same RSA signatures modulus is less than 2048 bits, or certificates whose ECC public keys
plus ECDSA signatures for certificates with ECC key. are in groups whose order is less than 256 bits. RSA signing
certificates with 2048-bit public keys MUST be supported, and such
certificates with longer public keys MAY be supported. ECDSA
certificates using the NIST P-256 curve MUST be supported, and such
certificates using the P-384 and P-521 curves SHOULD be supported.
ACP nodes MUST support RSA certificates that are signed by RSA
signatures over the SHA-256 digest of the contents, and SHOULD
additionally support SHA-384 and SHA-512 digests in such signatures.
The same requirements for certificate signatures apply to ECDSA
certificates, and additionally, ACP nodes MUST support ECDSA
signatures on ECDSA certificates.
The ACP certificate SHOULD use an RSA key and an RSA signature when The ACP certificate SHOULD use an RSA key and an RSA signature when
the ACP certificate is intended to be used not only for ACP the ACP certificate is intended to be used not only for ACP
authentication but also for other purposes. The ACP certificate MAY authentication but also for other purposes. The ACP certificate MAY
use an ECC key and an ECDSA signature if the ACP certificate is only use an ECC key and an ECDSA signature if the ACP certificate is only
used for ACP and ANI authentication and authorization. used for ACP and ANI authentication and authorization.
Any secure channel protocols used for the ACP as specified in this Any secure channel protocols used for the ACP as specified in this
document or extensions of this document MUST therefore support document or extensions of this document MUST therefore support
authentication (e.g.:signing) starting with these type of authentication (e.g.:signing) starting with these type of
skipping to change at page 25, line 4 skipping to change at page 25, line 10
Any secure channel protocols used for the ACP as specified in this Any secure channel protocols used for the ACP as specified in this
document or extensions of this document MUST therefore support document or extensions of this document MUST therefore support
authentication (e.g.:signing) starting with these type of authentication (e.g.:signing) starting with these type of
certificates. See [RFC4492] for more information. certificates. See [RFC4492] for more information.
The reason for these choices are as follows: As of 2020, RSA is still The reason for these choices are as follows: As of 2020, RSA is still
more widely used than ECC, therefore the MUST for RSA. ECC offers more widely used than ECC, therefore the MUST for RSA. ECC offers
equivalent security at (logarithmically) shorter key lengths (see equivalent security at (logarithmically) shorter key lengths (see
[RFC4492]). This can be beneficial especially in the presence of [RFC4492]). This can be beneficial especially in the presence of
constrained bandwidth or constrained nodes in an ACP/ANI network. constrained bandwidth or constrained nodes in an ACP/ANI network.
Some ACP functions such as GRASP peer-2-peer across the ACP require Some ACP functions such as GRASP peer-2-peer across the ACP require
end-to-end/any-to-any authentication/authorization, therefore ECC can end-to-end/any-to-any authentication/authorization, therefore ECC can
only reliably be used in the ACP when it MUST be supported on all ACP only reliably be used in the ACP when it MUST be supported on all ACP
nodes. RSA signatures are mandatory to be supported also for ECC nodes. RSA signatures are mandatory to be supported also for ECC
certificates because CAs themselves may not support ECC yet. certificates because CAs themselves may not support ECC yet.
The ACP certificate SHOULD be used for any authentication between The ACP certificate SHOULD be used for any authentication between
nodes with ACP domain certificates (ACP nodes and NOC nodes) where nodes with ACP domain certificates (ACP nodes and NOC nodes) where a
the required authorization condition is ACP domain membership, such required authorization condition is ACP domain membership, such as
as ACP node to NOC/OAM end-to-end security and ASA to ASA end-to-end ACP node to NOC/OAM end-to-end security and ASA to ASA end-to-end
security. Section 6.1.3 defines this "ACP domain membership check". security. Section 6.2.3 defines this "ACP domain membership check".
The uses of this check that are standardized in this document are for The uses of this check that are standardized in this document are for
the establishment of hop-by-hop ACP secure channels (Section 6.6) and the establishment of hop-by-hop ACP secure channels (Section 6.7) and
for ACP GRASP (Section 6.8.2) end-to-end via TLS 1.2 ([RFC5246]). for ACP GRASP (Section 6.9.2) end-to-end via TLS.
The ACP domain membership check requires a minimum amount of elements The ACP domain membership check requires a minimum amount of elements
in a certificate as described in Section 6.1.3. The identity of a in a certificate as described in Section 6.2.3. The identity of a
node in the ACP is carried via the acp-node-name as defined in node in the ACP is carried via the acp-node-name as defined in
Section 6.1.2. Section 6.2.2.
In support of ECDH key establishment, ACP certificates with ECC keys In support of ECDH key establishment, ACP certificates with ECC keys
MUST indicate to be Elliptic Curve Diffie-Hellman capable (ECDH) if MUST indicate to be Elliptic Curve Diffie-Hellman capable (ECDH): If
X.509 v3 keyUsage and extendedKeyUsage are included in the the X.509v3 keyUsage extension is present, the keyAgreement bit MUST
certificate. be set.
Any other field of the ACP certificate is to be populated as required Any other fields of the ACP certificate are to be populated as
by [RFC5280] or desired by the operator of the ACP domain ACP required by [RFC5280]: As long as they are compliant with [RFC5280],
registrars/CA and required by other purposes that the ACP certificate any other field of an ACP certificate can be set as desired by the
is intended to be used for. operator of the ACP domain through appropriate ACP registrar/ACP CA
procedures. For example, other fields may be required for other
purposes that the ACP certificate is intended to be used for (such as
elements of a SubjectName).
For further certificate details, ACP certificates may follow the For further certificate details, ACP certificates may follow the
recommendations from [CABFORUM]. recommendations from [CABFORUM].
For diagnostic and other operational purposes, it is beneficial to For diagnostic and other operational purposes, it is beneficial to
copy the device identifying fields of the node's IDevID certificate copy the device identifying fields of the node's IDevID certificate
into the ACP certificate, such as the "serialNumber" (see into the ACP certificate, such as the [X.520], section 6.2.9
[I-D.ietf-anima-bootstrapping-keyinfra] section 2.3.1). This can be "serialNumber" attribute in the subjects field distinguished name
done for example if it would be acceptable for the devices encoding. Note that this is not the certificate serial number. See
also [I-D.ietf-anima-bootstrapping-keyinfra] section 2.3.1. This can
be done for example if it would be acceptable for the device's
"serialNumber" to be signalled via the Link Layer Discovery Protocol "serialNumber" to be signalled via the Link Layer Discovery Protocol
(LLDP, [LLDP]) because like LLDP signalled information, the ACP (LLDP, [LLDP]) because like LLDP signalled information, the ACP
certificate information can be retrieved by neighboring nodes without certificate information can be retrieved by neighboring nodes without
further authentication and be used either for beneficial diagnostics further authentication and be used either for beneficial diagnostics
or for malicious attacks. Retrieval of the ACP certificate is or for malicious attacks. Retrieval of the ACP certificate is
possible via a (failing) attempt to set up an ACP secure channel, and possible via a (failing) attempt to set up an ACP secure channel, and
the "serialNumber" contains usually device type information that may the "serialNumber" usually contains device type information that may
help to faster determine working exploits/attacks against the device. help to faster determine working exploits/attacks against the device.
Note that there is no intention to constrain authorization within the Note that there is no intention to constrain authorization within the
ACP or autonomic networks using the ACP to just the ACP domain ACP or autonomic networks using the ACP to just the ACP domain
membership check as defined in this document. It can be extended or membership check as defined in this document. It can be extended or
modified with future requirements. Such future authorizations can modified with additional requirements. Such future authorizations
use and require additional elements in certificates or policies or can use and require additional elements in certificates or policies
even additional certificates. For an example, see Appendix A.10.5. or even additional certificates. See the additional check agagainst
the id-kp-cmcRA [RFC6402] extended key usage attribute
(Section 6.2.5) and for possible future extensions, see
Appendix A.10.5.
6.1.2. ACP Certificate AcpNodeName 6.2.2. ACP Certificate AcpNodeName
acp-node-name = local-part "@" acp-domain-name acp-node-name = local-part "@" acp-domain-name
local-part = [ acp-address ] [ "+" rsub extensions ] local-part = [ acp-address ] [ "+" rsub extensions ]
HEXLC = DIGIT / "a" / "b" / "c" / "d" / "e" / "f" acp-address = 32HEXDIG | "0" ; HEXDIG as of RFC5234 section B.1
; DIGIT as of RFC5234 section B.1
acp-address = 32HEXLC | "0"
rsub = [ <subdomain> ] ; <subdomain> as of RFC1034, section 3.5 rsub = [ <subdomain> ] ; <subdomain> as of RFC1034, section 3.5
acp-domain-name = ; <domain> ; as of RFC 1034, section 3.5 acp-domain-name = ; <domain> ; as of RFC 1034, section 3.5
extensions = *( "+" extension ) extensions = *( "+" extension )
extension = ; future standard definition. extension = 1*etext ; future standard definition.
; Must fit RFC5322 simple dot-atom format. etext = ALPHA / DIGIT / ; Printable US-ASCII
"!" / "#" / "$" / "%" / "&" / "'" /
"*" / "-" / "/" / "=" / "?" / "^" /
"_" / "`" / "{" / "|" / "}" / "~"
routing-subdomain = [ rsub "." ] acp-domain-name routing-subdomain = [ rsub "." ] acp-domain-name
Example: Example:
given an ACP address of fd89:b714:f3db:0:200:0:6400:0000 given an ACP address of fd89:b714:f3db:0:200:0:6400:0000
and an ACP domain-name of acp.example.com and an ACP domain-name of acp.example.com
and an rsub extenstion of area51.research and an rsub extenstion of area51.research
then this results in: then this results in:
acp-node-name = fd89b714F3db00000200000064000000 acp-node-name = fd89b714f3db00000200000064000000
+area51.research@acp.example.com +area51.research@acp.example.com
acp-domain-name = acp.example.com acp-domain-name = acp.example.com
routing-subdomain = area51.research.acp.example.com routing-subdomain = area51.research.acp.example.com
Figure 2: ACP Node Name ABNF Figure 2: ACP Node Name ABNF
acp-node-name in above Figure 2 is the ABNF ([RFC5234]) definition of acp-node-name in above Figure 2 is the ABNF ([RFC5234]) definition of
the ACP Node Name. An ACP certificate MUST carry this information. the ACP Node Name. An ACP certificate MUST carry this information.
It MUST be encoded as a subjectAltName / otherName / AcpNodeName as It MUST be encoded as a subjectAltName / otherName / AcpNodeName as
described in Section 6.1.2.1. described in Section 6.2.2.1.
Nodes complying with this specification MUST be able to receive their Nodes complying with this specification MUST be able to receive their
ACP address through the domain certificate, in which case their own ACP address through the domain certificate, in which case their own
ACP certificate MUST have a 32HEXLC "acp-address" field. Nodes ACP certificate MUST have a 32HEXDIG acp-address field. Acp-address
complying with this specification MUST also be able to authenticate is case insensitive because ABNF HEXDIG is. It is recommended to
nodes as ACP domain members or ACP secure channel peers when they encode acp-address with lower case letters. Nodes complying with
have a 0-value acp-address field and as ACP domain members (but not this specification MUST also be able to authenticate nodes as ACP
as ACP secure channel peers) when they have an empty acp-address domain members or ACP secure channel peers when they have a 0-value
field. See Section 6.1.3. acp-address field and as ACP domain members (but not as ACP secure
channel peers) when the acp-address field is omitted from their
AcpNodeName. See Section 6.2.3.
acp-domain-name is used to indicate the ACP Domain across which ACP acp-domain-name is used to indicate the ACP Domain across which ACP
nodes authenticate and authorize each other, for example to build ACP nodes authenticate and authorize each other, for example to build ACP
secure channels to each other, see Section 6.1.3. acp-domain-name secure channels to each other, see Section 6.2.3. acp-domain-name
SHOULD be the FQDN of an Internet domain owned by the network SHOULD be the FQDN of an Internet domain owned by the network
administration of the ACP and ideally reserved to only be used for administration of the ACP and ideally reserved to only be used for
the ACP. In this specification it serves to be a name for the ACP the ACP. In this specification it serves to be a name for the ACP
that ideally is globally unique. When acp-domain-name is a globally that ideally is globally unique. When acp-domain-name is a globally
unique name, collision of ACP addresses across different ACP domains unique name, collision of ACP addresses across different ACP domains
can only happen due to ULA hash collisions (see Section 6.10.2). can only happen due to ULA hash collisions (see Section 6.11.2).
Using different acp-domain-names, operators can distinguish multiple Using different acp-domain-names, operators can distinguish multiple
ACP even when using the same TA. ACP even when using the same TA.
To keep the encoding simple, there is no consideration for To keep the encoding simple, there is no consideration for
internationalized acp-domain-names. The acp-node-name is not internationalized acp-domain-names. The acp-node-name is not
intended for end user consumption, and there is no protection against intended for end user consumption. There is no protection against an
someone not owning a domain name to simply choose it. Instead, it operator to pick any domain name for an ACP whether or not the
serves as a hash seed for the ULA and for diagnostics to the operator can claim to own the domain name. Instead, the domain name
only serves as a hash seed for the ULA and for diagnostics to the
operator. Therefore, any operator owning only an internationalized operator. Therefore, any operator owning only an internationalized
domain name should be able to pick an equivalently unique 7-bit ASCII domain name should be able to pick an equivalently unique 7-bit ASCII
acp-domain-name string representing the internationalized domain acp-domain-name string representing the internationalized domain
name. name.
"routing-subdomain" is a string that can be constructed from the acp- "routing-subdomain" is a string that can be constructed from the acp-
node-name, and it is used in the hash-creation of the ULA (see node-name, and it is used in the hash-creation of the ULA (see
below). The presence of the "rsub" component allows a single ACP below). The presence of the "rsub" component allows a single ACP
domain to employ multiple /48 ULA prefixes. See Appendix A.7 for domain to employ multiple /48 ULA prefixes. See Appendix A.7 for
example use-cases. example use-cases.
skipping to change at page 27, line 41 skipping to change at page 28, line 9
example use-cases. example use-cases.
The optional "extensions" field is used for future standardized The optional "extensions" field is used for future standardized
extensions to this specification. It MUST be ignored if present and extensions to this specification. It MUST be ignored if present and
not understood. not understood.
The following points explain and justify the encoding choices The following points explain and justify the encoding choices
described: described:
1. Formatting notes: 1. Formatting notes:
1.1 "rsub" needs to be in the "local-part": If the format just 1.1 "rsub" needs to be in the "local-part": If the format just
had routing-subdomain as the domain part of the acp-node- had routing-subdomain as the domain part of the acp-node-
name, rsub and acp-domain-name could not be separated from name, rsub and acp-domain-name could not be separated from
each other to determine in the ACP domain membership check each other to determine in the ACP domain membership check
which part is the acp-domain-name and which is solely for which part is the acp-domain-name and which is solely for
creating a different ULA prefix. creating a different ULA prefix.
1.2 If both "acp-address" and "rsub" are omitted from
1.2 If "acp-address" is empty, and "rsub" is empty too, the AcpNodeName, the "local-part" will have the format
"local-part" will have the format ":++extension(s)". The "++extension(s)". The two plus characters are necessary so
two plus characters are necessary so the node can the node can unambiguously parse that both "acp-address" and
unambiguously parse that both "acp-address" and "rsub" are "rsub" are omitted.
empty.
2. The encoding of the ACP domain name and ACP address as described 2. The encoding of the ACP domain name and ACP address as described
in this section is used for the following reasons: in this section is used for the following reasons:
2.1 The acp-node-name is the identifier of a node's ACP. It 2.1 The acp-node-name is the identifier of a node's ACP. It
includes the necessary components to identify a nodes ACP includes the necessary components to identify a node's ACP
both from within the ACP as well as from the outside of the both from within the ACP as well as from the outside of the
ACP. ACP.
2.2 For manual and/or automated diagnostics and backend 2.2 For manual and/or automated diagnostics and backend
management of devices and ACPs, it is necessary to have an management of devices and ACPs, it is necessary to have an
easily human readable and software parsed standard, single easily human readable and software parsed standard, single
string representation of the information in the acp-node- string representation of the information in the acp-node-
name. For example, inventory or other backend systems can name. For example, inventory or other backend systems can
always identify an entity by one unique string field but not always identify an entity by one unique string field but not
by a combination of multiple fields, which would be by a combination of multiple fields, which would be
necessary if there was no single string representation. necessary if there was no single string representation.
2.3 If the encoding was not that of such a string, it would be 2.3 If the encoding was not that of such a string, it would be
necessary to define a second standard encoding to provide necessary to define a second standard encoding to provide
this format (standard string encoding) for operator this format (standard string encoding) for operator
consumption. consumption.
2.4 Addresses of the form <local>@<domain> have become the
2.4 Addresses of the form <local><@domain> have become the
preferred format for identifiers of entities in many preferred format for identifiers of entities in many
systems, including the majority of user identification in systems, including the majority of user identification in
web or mobile applications such as multi-domain single-sign- web or mobile applications such as multi-domain single-sign-
on systems. on systems.
3. Compatibilities: 3. Compatibilities:
3.1 It should be possible to use the ACP certificate as an 3.1 It should be possible to use the ACP certificate as an
LDevID certificate on the system for other uses beside the LDevID certificate on the system for other uses beside the
ACP. Therefore, the information element required for the ACP. Therefore, the information element required for the
ACP should be encoded so that it minimizes the possibility ACP should be encoded so that it minimizes the possibility
of creating incompatibilities with such other uses. The of creating incompatibilities with such other uses. The
subjectName is for example often used as an entity attributes of the subject field for example are often used
identifier in non-ACP uses of a the ACP certificate. in non-ACP applications and should therefore not be occupied
by new ACP values.
3.2 The element should not require additional ASN.1 en/decoding, 3.2 The element should not require additional ASN.1 en/decoding,
because libraries to access certificate information because libraries to access certificate information
especially for embedded devices may not support extended especially for embedded devices may not support extended
ASN.1 decoding beyond predefined, mandatory fields. ASN.1 decoding beyond predefined, mandatory fields.
subjectAltName / otherName is already used with a single subjectAltName / otherName is already used with a single
string parameter for several otherNames (see [RFC3920], string parameter for several otherNames (see [RFC3920],
[RFC7585], [RFC4985], [RFC8398]). [RFC7585], [RFC4985], [RFC8398]).
3.3 The element required for the ACP should minimize the risk of 3.3 The element required for the ACP should minimize the risk of
being misinterpreted by other uses of the LDevID being misinterpreted by other uses of the LDevID
certificate. It also must not be misinterpreted to actually certificate. It also must not be misinterpreted to actually
be an email address, hence the use of the otherName / be an email address, hence the use of the otherName /
rfc822Name option in the certificate would be inappropriate. rfc822Name option in the certificate would be inappropriate.
See section 4.2.1.6 of [RFC5280] for details on the subjectAltName See section 4.2.1.6 of [RFC5280] for details on the subjectAltName
field. field.
6.1.2.1. AcpNodeName ASN.1 Module 6.2.2.1. AcpNodeName ASN.1 Module
The following ASN.1 module normatively specifies the AcpNodeName The following ASN.1 module normatively specifies the AcpNodeName
structure. This specification uses the ASN.1 definitions from structure. This specification uses the ASN.1 definitions from
[RFC5912] with the 2002 ASN.1 notation used in that document. [RFC5912] with the 2002 ASN.1 notation used in that document.
[RFC5912] updates normative documents using older ASN.1 notation. [RFC5912] updates normative documents using older ASN.1 notation.
ANIMA-ACP-2020 ANIMA-ACP-2020
{ iso(1) identified-organization(3) dod(6) { iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) id-mod(0) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-anima-acpnodename-2020(IANA1) } id-mod-anima-acpnodename-2020(IANA1) }
DEFINITIONS IMPLICIT TAGS ::= DEFINITIONS IMPLICIT TAGS ::=
BEGIN BEGIN
IMPORTS IMPORTS
OTHER-NAME OTHER-NAME
FROM PKIX1Implicit-2009 FROM PKIX1Implicit-2009
{ iso(1) identified-organization(3) dod(6) internet(1) security(5) { iso(1) identified-organization(3) dod(6) internet(1)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-implicit-02(59) } security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-implicit-02(59) }
id-pkix id-pkix
FROM PKIX1Explicit-2009 FROM PKIX1Explicit-2009
{ iso(1) identified-organization(3) dod(6) internet(1) security(5) { iso(1) identified-organization(3) dod(6) internet(1)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-explicit-02(51) } ; security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-explicit-02(51) } ;
id-on OBJECT IDENTIFIER ::= { id-pkix 8 } id-on OBJECT IDENTIFIER ::= { id-pkix 8 }
AcpNodeNameOtherNames OTHER-NAME ::= { on-AcpNodeName, ... } AcpNodeNameOtherNames OTHER-NAME ::= { on-AcpNodeName, ... }
on-AcpNodeName OTHER-NAME ::= { on-AcpNodeName OTHER-NAME ::= {
AcpNodeName IDENTIFIED BY id-on-AcpNodeName AcpNodeName IDENTIFIED BY id-on-AcpNodeName
} }
id-on-AcpNodeName OBJECT IDENTIFIER ::= { id-on IANA2 } id-on-AcpNodeName OBJECT IDENTIFIER ::= { id-on IANA2 }
AcpNodeName ::= IA5String (SIZE (1..MAX)) AcpNodeName ::= IA5String (SIZE (1..MAX))
-- AcpNodeName as specified in this document carries the -- AcpNodeName as specified in this document carries the
-- acp-node-name as specified in the ABNF in Section 6.1.2 -- acp-node-name as specified in the ABNF in Section 6.1.2
END END
6.1.3. ACP domain membership check Figure 3
6.2.3. ACP domain membership check
The following points constitute the ACP domain membership check of a The following points constitute the ACP domain membership check of a
candidate peer via its certificate: candidate peer via its certificate:
1: The peer has proved ownership of the private key associated with 1: The peer has proved ownership of the private key associated with
the certificate's public key. This check is performed by the the certificate's public key. This check is performed by the
security association protocol used, for example [RFC7296], section security association protocol used, for example [RFC7296], section
2.15. 2.15.
2: The peer's certificate passes certificate path validation as 2: The peer's certificate passes certificate path validation as
defined in [RFC5280], section 6 against one of the TA associated defined in [RFC5280], section 6 against one of the TA associated
with the ACP node's ACP certificate (see Section 6.1.4 below). with the ACP node's ACP certificate (see Section 6.2.4 below).
This includes verification of the validity (lifetime) of the This includes verification of the validity (lifetime) of the
certificates in the path. certificates in the path.
3: If the peer's certificate indicates a Certificate Revocation List
3: If the node certificate indicates a Certificate Revocation List
(CRL) Distribution Point (CRLDP) ([RFC5280], section 4.2.1.13) or (CRL) Distribution Point (CRLDP) ([RFC5280], section 4.2.1.13) or
Online Certificate Status Protocol (OCSP) responder ([RFC5280], Online Certificate Status Protocol (OCSP) responder ([RFC5280],
section 4.2.2.1), then the peer's certificate MUST be valid section 4.2.2.1), then the peer's certificate MUST be valid
according to those mechanisms when they are available: An OCSP according to those mechanisms when they are available: An OCSP
check for the peer's certificate across the ACP must succeed or check for the peer's certificate across the ACP must succeed or
the peer certificate must not be listed in the CRL retrieved from the peer certificate must not be listed in the CRL retrieved from
the CRLDP. These mechanisms are not available when the node has the CRLDP. These mechanisms are not available when the ACP node
no ACP or non-ACP connectivity to retrieve a current CRL or access has no ACP or non-ACP connectivity to retrieve a current CRL or
an OCSP responder and the security association protocol itself has access an OCSP responder and the security association protocol
also no way to communicate CRL or OCSP check. itself has also no way to communicate CRL or OCSP check.
Retries to learn revocation via OCSP/CRL SHOULD be made using the
Retries to learn revocation via OCSP/CRL SHOULD be made using same backoff as described in Section 6.7. If and when the ACP
the same backoff as described in Section 6.6. If and when the ACP
node then learns that an ACP peer's certificate is invalid for node then learns that an ACP peer's certificate is invalid for
which rule 3 had to be skipped during ACP secure channel which rule 3 had to be skipped during ACP secure channel
establishment, then the ACP secure channel to that peer MUST be establishment, then the ACP secure channel to that peer MUST be
closed even if this peer is the only connectivity to access CRL/ closed even if this peer is the only connectivity to access CRL/
OCSP. This applies (of course) to all ACP secure channels to this OCSP. This applies (of course) to all ACP secure channels to this
peer if there are multiple. The ACP secure channel connection peer if there are multiple. The ACP secure channel connection
MUST be retried periodically to support the case that the neighbor MUST be retried periodically to support the case that the neighbor
acquires a new, valid certificate. acquires a new, valid certificate.
4: The peer's certificate has a syntactically valid acp-node-name
4: The peer's certificate has a syntactically valid acp-node-name
field and the acp-domain-name in that peer's acp-node-name is the field and the acp-domain-name in that peer's acp-node-name is the
same as in this ACP node's certificate (lowercase normalized). same as in this ACP node's certificate (lowercase normalized).
When checking a candidate peer's certificate for the purpose of When checking a candidate peer's certificate for the purpose of
establishing an ACP secure channel, one additional check is establishing an ACP secure channel, one additional check is
performed: performed:
5: The candidate peer certificate's acp-node-name has a non-empty 5: The acp-address field of the candidate peer certificate's
acp-address field (either 32HEXLC or 0, according to Figure 2). AcpNodeName is not omitted but either 32HEXDIG or 0, according to
Figure 2.
Technically, ACP secure channels can only be built with nodes that Technically, ACP secure channels can only be built with nodes that
have an acp-address. Rule 5 ensures that this is taken into account have an acp-address. Rule 5 ensures that this is taken into account
during ACP domain membership check. during ACP domain membership check.
Nodes with an empty acp-address field can only use their ACP domain Nodes with an omitted acp-address field can only use their ACP domain
certificate for non-ACP-secure channel authentication purposes. This certificate for non-ACP-secure channel authentication purposes. This
includes for example NMS type nodes permitted to communicate into the includes for example NMS type nodes permitted to communicate into the
ACP via ACP connect (Section 8.1) ACP via ACP connect (Section 8.1)
The special value 0 in an ACP certificates acp-address field is used The special value 0 in an ACP certificates acp-address field is used
for nodes that can and should determine their ACP address through for nodes that can and should determine their ACP address through
other mechanisms than learning it through the acp-address field in other mechanisms than learning it through the acp-address field in
their ACP certificate. These ACP nodes are permitted to establish their ACP certificate. These ACP nodes are permitted to establish
ACP secure channels. Mechanisms for those nodes to determine their ACP secure channels. Mechanisms for those nodes to determine their
ACP address are outside the scope of this specification, but this ACP address are outside the scope of this specification, but this
option is defined here so that any ACP nodes can build ACP secure option is defined here so that any ACP nodes can build ACP secure
channels to them according to Rule 5. channels to them according to Rule 5.
The optional rsub field of the AcpNodeName is not relevant to the ACP
domain membership check because it only serves to structure routing
and addressing within an ACP but not to segment mutual
authentication/authorization (hence the name "routing subdomain").
In summary: In summary:
Steps 1...4 constitute standard certificate validity verification * Steps 1...4 constitute standard certificate validity verification
and private key authentication as defined by [RFC5280] and and private key authentication as defined by [RFC5280] and
security association protocols (such as Internet Key Exchange security association protocols (such as Internet Key Exchange
Protocol version 2 IKEv2 [RFC7296] when leveraging certificates. Protocol version 2 IKEv2 [RFC7296] when leveraging certificates.
* Steps 1...4 do not include verification of any pre-existing form
Steps 1...4 do not include verification of any pre-existing form
of non-public-key-only based identity elements of a certificate of non-public-key-only based identity elements of a certificate
such as a web servers domain name prefix often encoded in such as a web servers domain name prefix often encoded in
certificate common name. Steps 5 and 6 are the equivalent steps. certificate common name. Step 5 is an equivalent step for the
AcpNodeName.
Step 4 Constitutes standard CRL/OCSP checks refined for the case * Step 4 constitutes standard CRL/OCSP checks refined for the case
of missing connectivity and limited functionality security of missing connectivity and limited functionality security
association protocols. association protocols.
* Steps 1...4 authorize to build any secure connection between
Step 5 Checks for the presence of an ACP identity for the peer.
Steps 1...5 authorize to build any secure connection between
members of the same ACP domain except for ACP secure channels. members of the same ACP domain except for ACP secure channels.
* Step 5 is the additional verification of the presence of an ACP
Step 6 is the additional verification of the presence of an ACP address as necessary for ACP secure channels.
address. * Steps 1...5 therefore authorize to build an ACP secure channel.
Steps 1...6 authorize to build an ACP secure channel.
For brevity, the remainder of this document refers to this process For brevity, the remainder of this document refers to this process
only as authentication instead of as authentication and only as authentication instead of as authentication and
authorization. authorization.
6.1.3.1. Realtime clock and Time Validation 6.2.3.1. Realtime clock and Time Validation
An ACP node with a realtime clock in which it has confidence, MUST An ACP node with a realtime clock in which it has confidence, MUST
check the time stamps when performing ACP domain membership check check the time stamps when performing ACP domain membership check
such as as the certificate validity period in step 1. and the such as as the certificate validity period in step 1. and the
respective times in step 4 for revocation information (e.g., respective times in step 4 for revocation information (e.g.,
signingTimes in CMS signatures). signingTimes in CMS signatures).
An ACP node without such a realtime clock MAY ignore those time stamp An ACP node without such a realtime clock MAY ignore those time stamp
validation steps if it does not know the current time. Such an ACP validation steps if it does not know the current time. Such an ACP
node SHOULD obtain the current time in a secured fashion, such as via node SHOULD obtain the current time in a secured fashion, such as via
skipping to change at page 33, line 23 skipping to change at page 33, line 27
their link-local addresses SHOULD primarily run NTP across the ACP their link-local addresses SHOULD primarily run NTP across the ACP
and provide NTP time across the ACP only when they have a trusted and provide NTP time across the ACP only when they have a trusted
time source. Details for such NTP procedures are beyond the scope of time source. Details for such NTP procedures are beyond the scope of
this specification. this specification.
Beside ACP domain membership check, the ACP itself has no dependency Beside ACP domain membership check, the ACP itself has no dependency
against knowledge of the current time, but protocols and services against knowledge of the current time, but protocols and services
using the ACP will likeley have the need to know the current time. using the ACP will likeley have the need to know the current time.
For example event logging. For example event logging.
6.1.4. Trust Anchors (TA) 6.2.4. Trust Anchors (TA)
ACP nodes need TA information according to [RFC5280], section 6.1.1 ACP nodes need TA information according to [RFC5280], section 6.1.1
(d), typically in the form of one or more certificate of the TA to (d), typically in the form of one or more certificate of the TA to
perform certificate path validation as required by Section 6.1.3, perform certificate path validation as required by Section 6.2.3,
rule 2. TA information MUST be provisioned to an ACP node (together rule 2. TA information MUST be provisioned to an ACP node (together
with its ACP domain certificate) by an ACP Registrar during initial with its ACP domain certificate) by an ACP Registrar during initial
enrolment of a candidate ACP node. ACP nodes MUST also support enrollment of a candidate ACP node. ACP nodes MUST also support
renewal of TA information via Enrollment over Secure Transport (EST, renewal of TA information via EST as described below in
see [RFC7030]), as described below in Section 6.1.5. Section 6.2.5.
The required information about a TA can consist of not only a single, The required information about a TA can consist of not only a single,
but multiple certificates as required for dealing with CA certificate but multiple certificates as required for dealing with CA certificate
renewals as explained in Section 4.4 of CMP ([RFC4210]). renewals as explained in Section 4.4 of CMP ([RFC4210]).
A certificate path is a chain of certificates starting at the ACP A certificate path is a chain of certificates starting at the ACP
certificate (leaf/end-entity) followed by zero or more intermediate certificate (leaf/end-entity) followed by zero or more intermediate
CA certificates and ending with the TA information, which are CA certificates and ending with the TA information, which are
typically one or two the self-signed certificates of the TA. The CA typically one or two the self-signed certificates of the TA. The CA
that signs the ACP certificate is called the assigning CA. If there that signs the ACP certificate is called the assigning CA. If there
skipping to change at page 34, line 32 skipping to change at page 34, line 37
requirements typically exclude public CA, because they in general do requirements typically exclude public CA, because they in general do
not support the notion of trusted registrars vouching for the not support the notion of trusted registrars vouching for the
correctness of the fields of a requested certificate or would by correctness of the fields of a requested certificate or would by
themselves not be capable to validate the correctness of otherName / themselves not be capable to validate the correctness of otherName /
AcpNodeName. AcpNodeName.
A single owner can operate multiple independent ACP domains from the A single owner can operate multiple independent ACP domains from the
same set of TA. Registrars must then know which ACP a node needs to same set of TA. Registrars must then know which ACP a node needs to
be enrolled into. be enrolled into.
6.1.5. Certificate and Trust Anchor Maintenance 6.2.5. Certificate and Trust Anchor Maintenance
ACP nodes MUST support renewal of their Certificate and TA ACP nodes MUST support renewal of their Certificate and TA
information via EST ("Enrollment over Secure Transport", see information via EST and MAY support other mechanisms. See
[RFC7030]) and MAY support other mechanisms. An ACP network MUST Section 6.1 for TLS requirements. An ACP network MUST have at least
have at least one ACP node supporting EST server functionality across one ACP node supporting EST server functionality across the ACP so
the ACP so that EST renewal is useable. that EST renewal is useable.
ACP nodes SHOULD be able to remember the IPv6 locator parameters of ACP nodes SHOULD be able to remember the IPv6 locator parameters of
the O_IPv6_LOCATOR in GRASP of the EST server from which they last the O_IPv6_LOCATOR in GRASP of the EST server from which they last
renewed their ACP certificate. They SHOULD provide the ability for renewed their ACP certificate. They SHOULD provide the ability for
these EST server parameters to also be set by the ACP Registrar (see these EST server parameters to also be set by the ACP Registrar (see
Section 6.10.7) that initially enrolled the ACP device with its ACP Section 6.11.7) that initially enrolled the ACP device with its ACP
certificate. When BRSKI (see certificate. When BRSKI (see
[I-D.ietf-anima-bootstrapping-keyinfra]) is used, the IPv6 locator of [I-D.ietf-anima-bootstrapping-keyinfra]) is used, the IPv6 locator of
the BRSKI registrar from the BRSKI TLS connection SHOULD be the BRSKI registrar from the BRSKI TLS connection SHOULD be
remembered and used for the next renewal via EST if that registrar remembered and used for the next renewal via EST if that registrar
also announces itself as an EST server via GRASP (see next section) also announces itself as an EST server via GRASP (see next section)
on its ACP address. on its ACP address.
The EST server MUST present a certificate that is passing ACP domain The EST server MUST present a certificate that is passing ACP domain
membership check in its TLS connection setup (Section 6.1.3, rules membership check in its TLS connection setup (Section 6.2.3, rules
1..4, not rule 5 as this is not for an ACP secure channel setup). 1..4, not rule 5 as this is not for an ACP secure channel setup).
The EST server certificate MUST also contain the id-kp-cmcRA The EST server certificate MUST also contain the id-kp-cmcRA
[RFC6402] extended key usage extension and the EST client MUST check [RFC6402] extended key usage attribute and the EST client MUST check
its presence. its presence.
The additional check against the id-kp-cmcRA extended key usage The additional check against the id-kp-cmcRA extended key usage
extension field ensures that clients do not fall prey to an illicit extension field ensures that clients do not fall prey to an illicit
EST server. While such illicit EST servers should not be able to EST server. While such illicit EST servers should not be able to
support certificate signing requests (as they are not able to elicit support certificate signing requests (as they are not able to elicit
a signing response from a valid CA), such an illicit EST server would a signing response from a valid CA), such an illicit EST server would
be able to provide faked CA certificates to EST clients that need to be able to provide faked CA certificates to EST clients that need to
renew their CA certificates when they expire. renew their CA certificates when they expire.
Note that EST servers supporting multiple ACP domains will need to Note that EST servers supporting multiple ACP domains will need to
have for each of these ACP domains a separate certificate and respond have for each of these ACP domains a separate certificate and respond
on a different transport address (IPv6 address and/or TCP port), but on a different transport address (IPv6 address and/or TCP port), but
this is easily automated on the EST server as long as the CA does not this is easily automated on the EST server as long as the CA does not
restrict registrars to request certificates with the id-kp-cmcRA restrict registrars to request certificates with the id-kp-cmcRA
extended usage extension for themselves. extended usage extension for themselves.
6.1.5.1. GRASP objective for EST server 6.2.5.1. GRASP objective for EST server
ACP nodes that are EST servers MUST announce their service via GRASP ACP nodes that are EST servers MUST announce their service via GRASP
in the ACP through M_FLOOD messages. See [I-D.ietf-anima-grasp], in the ACP through M_FLOOD messages. See [I-D.ietf-anima-grasp],
section 2.8.11 for the definition of this message type: section 2.8.11 for the definition of this message type:
Example: Example:
[M_FLOOD, 12340815, h'fd89b714f3db0000200000064000001', 210000, [M_FLOOD, 12340815, h'fd89b714f3db0000200000064000001', 210000,
[["SRV.est", 4, 255 ], [["SRV.est", 4, 255 ],
[O_IPv6_LOCATOR, [O_IPv6_LOCATOR,
h'fd89b714f3db0000200000064000001', IPPROTO_TCP, 443]] h'fd89b714f3db0000200000064000001', IPPROTO_TCP, 443]]
] ]
Figure 3: GRASP SRV.est example Figure 4: GRASP SRV.est example
The formal definition of the objective in Concise data definition The formal definition of the objective in Concise data definition
language (CDDL) (see [RFC8610]) is as follows: language (CDDL) (see [RFC8610]) is as follows:
flood-message = [M_FLOOD, session-id, initiator, ttl, flood-message = [M_FLOOD, session-id, initiator, ttl,
+[objective, (locator-option / [])]] +[objective, (locator-option / [])]]
; see example above and explanation ; see example above and explanation
; below for initiator and ttl ; below for initiator and ttl
objective = ["SRV.est", objective-flags, loop-count, objective = ["SRV.est", objective-flags, loop-count,
objective-value] objective-value]
objective-flags = sync-only ; as in GRASP spec objective-flags = sync-only ; as in GRASP spec
sync-only = 4 ; M_FLOOD only requires synchronization sync-only = 4 ; M_FLOOD only requires synchronization
loop-count = 255 ; recommended as there is no mechanism loop-count = 255 ; recommended as there is no mechanism
; to discover network diameter. ; to discover network diameter.
objective-value = any ; reserved for future extensions objective-value = any ; reserved for future extensions
Figure 4: GRASP SRV.est definition Figure 5: GRASP SRV.est definition
The objective name "SRV.est" indicates that the objective is an The objective name "SRV.est" indicates that the objective is an
[RFC7030] compliant EST server because "est" is an [RFC6335] [RFC7030] compliant EST server because "est" is an [RFC6335]
registered service name for [RFC7030]. Objective-value MUST be registered service name for [RFC7030]. Objective-value MUST be
ignored if present. Backward compatible extensions to [RFC7030] MAY ignored if present. Backward compatible extensions to [RFC7030] MAY
be indicated through objective-value. Non [RFC7030] compatible be indicated through objective-value. Non [RFC7030] compatible
certificate renewal options MUST use a different objective-name. certificate renewal options MUST use a different objective-name.
Non-recognized objective-values (or parts thereof if it is a Non-recognized objective-values (or parts thereof if it is a
structure partially understood) MUST be ignored. structure partially understood) MUST be ignored.
skipping to change at page 36, line 46 skipping to change at page 36, line 46
three consecutive messages can be dropped before considering an three consecutive messages can be dropped before considering an
announcement expired. In the example above, the ttl is 210000 msec, announcement expired. In the example above, the ttl is 210000 msec,
3.5 times 60 seconds. When a service announcer using these 3.5 times 60 seconds. When a service announcer using these
parameters unexpectedly dies immediately after sending the M_FLOOD, parameters unexpectedly dies immediately after sending the M_FLOOD,
receivers would consider it expired 210 seconds later. When a receivers would consider it expired 210 seconds later. When a
receiver tries to connect to this dead service before this timeout, receiver tries to connect to this dead service before this timeout,
it will experience a failing connection and use that as an indication it will experience a failing connection and use that as an indication
that the service instance is dead and select another instance of the that the service instance is dead and select another instance of the
same service instead (from another GRASP announcement). same service instead (from another GRASP announcement).
6.1.5.2. Renewal The "SRV.est" objective(s) SHOULD only be announced when the ACP node
knows that it can successfully communicate with a CA to perform the
EST renewal/rekeying operations for the ACP domain. See also
Section 11.
6.2.5.2. Renewal
When performing renewal, the node SHOULD attempt to connect to the When performing renewal, the node SHOULD attempt to connect to the
remembered EST server. If that fails, it SHOULD attempt to connect remembered EST server. If that fails, it SHOULD attempt to connect
to an EST server learned via GRASP. The server with which to an EST server learned via GRASP. The server with which
certificate renewal succeeds SHOULD be remembered for the next certificate renewal succeeds SHOULD be remembered for the next
renewal. renewal.
Remembering the last renewal server and preferring it provides Remembering the last renewal server and preferring it provides
stickiness which can help diagnostics. It also provides some stickiness which can help diagnostics. It also provides some
protection against off-path compromised ACP members announcing bogus protection against off-path compromised ACP members announcing bogus
information into GRASP. information into GRASP.
Renewal of certificates SHOULD start after less than 50% of the Renewal of certificates SHOULD start after less than 50% of the
domain certificate lifetime so that network operations has ample time domain certificate lifetime so that network operations has ample time
to investigate and resolve any problems that causes a node to not to investigate and resolve any problems that causes a node to not
renew its domain certificate in time - and to allow prolonged periods renew its domain certificate in time - and to allow prolonged periods
of running parts of a network disconnected from any CA. of running parts of a network disconnected from any CA.
6.1.5.3. Certificate Revocation Lists (CRLs) 6.2.5.3. Certificate Revocation Lists (CRLs)
The ACP node SHOULD support revocation through CRL(s) via HTTP from The ACP node SHOULD support revocation through CRL(s) via HTTP from
one or more CRL Distribution Points (CRLDP). The CRLDP(s) MUST be one or more CRL Distribution Points (CRLDP). The CRLDP(s) MUST be
indicated in the Domain Certificate when used. If the CRLDP URL uses indicated in the Domain Certificate when used. If the CRLDP URL uses
an IPv6 address (ULA address when using the addressing rules an IPv6 address (ULA address when using the addressing rules
specified in this document), the ACP node will connect to the CRLDP specified in this document), the ACP node will connect to the CRLDP
via the ACP. If the CRLDP uses a domain name, the ACP node will via the ACP. If the CRLDP uses a domain name, the ACP node will
connect to the CRLDP via the Data-Plane. connect to the CRLDP via the Data-Plane.
It is common to use domain names for CRLDP(s), but there is no It is common to use domain names for CRLDP(s), but there is no
requirement for the ACP to support DNS. Any DNS lookup in the Data- requirement for the ACP to support DNS. Any DNS lookup in the Data-
Plane is not only a possible security issue, but it would also not Plane is not only a possible security issue, but it would also not
indicate whether the resolved address is meant to be reachable across indicate whether the resolved address is meant to be reachable across
the ACP. Therefore, the use of an IPv6 address versus the use of a the ACP. Therefore, the use of an IPv6 address versus the use of a
DNS name doubles as an indicator whether or not to reach the CRLDP DNS name doubles as an indicator whether or not to reach the CRLDP
via the ACP. via the ACP.
A CRLDP can be reachable across the ACP either by running it on a A CRLDP can be reachable across the ACP either by running it on a
node with ACP or by connecting its node via an ACP connect interface node with ACP or by connecting its node via an ACP connect interface
(see Section 8.1). The CRLDP SHOULD use an ACP certificate for its (see Section 8.1).
HTTPs connections. The connecting ACP node SHOULD verify that the
CRLDP certificate used during the HTTPs connection has the same ACP
address as indicated in the CRLDP URL of the node's ACP certificate
if the CRLDP URL uses an IPv6 address.
6.1.5.4. Lifetimes When using a private PKI for ACP certificates, the CRL may be need-
to-know, for example to prohibit insight into the operational
practices of the domain by tracking the growth of the CRL. In this
case, HTTPS may be chosen to provide confidentiality, especially when
making the CRL available via the Data-Plane. Authentication and
authorization SHOULD use ACP certificates and ACP domain membership
check. The CRLDP MAY omit the CRL verification during authentication
of the peer to permit retrieval of the CRL by an ACP node with
revoked ACP certificate. This can allow for that (ex) ACP node to
quickly discover its ACP certificate revocation. This may violate
the desired need-to-know requirement though. ACP nodes MAY support
CRLDP operations via HTTPS.
6.2.5.4. Lifetimes
Certificate lifetime may be set to shorter lifetimes than customary Certificate lifetime may be set to shorter lifetimes than customary
(1 year) because certificate renewal is fully automated via ACP and (1 year) because certificate renewal is fully automated via ACP and
EST. The primary limiting factor for shorter certificate lifetimes EST. The primary limiting factor for shorter certificate lifetimes
is load on the EST server(s) and CA. It is therefore recommended is load on the EST server(s) and CA. It is therefore recommended
that ACP certificates are managed via a CA chain where the assigning that ACP certificates are managed via a CA chain where the assigning
CA has enough performance to manage short lived certificates. See CA has enough performance to manage short lived certificates. See
also Section 9.2.4 for discussion about an example setup achieving also Section 9.2.4 for discussion about an example setup achieving
this. See also [I-D.ietf-acme-star]. this. See also [I-D.ietf-acme-star].
When certificate lifetimes are sufficiently short, such as few hours, When certificate lifetimes are sufficiently short, such as few hours,
certificate revocation may not be necessary, allowing to simplify the certificate revocation may not be necessary, allowing to simplify the
overall certificate maintenance infrastructure. overall certificate maintenance infrastructure.
See Appendix A.2 for further optimizations of certificate maintenance See Appendix A.2 for further optimizations of certificate maintenance
when BRSKI can be used ("Bootstrapping Remote Secure Key when BRSKI can be used ("Bootstrapping Remote Secure Key
Infrastructures", see [I-D.ietf-anima-bootstrapping-keyinfra]). Infrastructures", see [I-D.ietf-anima-bootstrapping-keyinfra]).
6.1.5.5. Re-enrollment 6.2.5.5. Re-enrollment
An ACP node may determine that its ACP certificate has expired, for An ACP node may determine that its ACP certificate has expired, for
example because the ACP node was powered down or disconnected longer example because the ACP node was powered down or disconnected longer
than its certificate lifetime. In this case, the ACP node SHOULD than its certificate lifetime. In this case, the ACP node SHOULD
convert to a role of a re-enrolling candidate ACP node. convert to a role of a re-enrolling candidate ACP node.
In this role, the node does maintain the TA and certificate chain In this role, the node does maintain the TA and certificate chain
associated with its ACP certificate exclusively for the purpose of associated with its ACP certificate exclusively for the purpose of
re-enrollment, and attempts (or waits) to get re-enrolled with a new re-enrollment, and attempts (or waits) to get re-enrolled with a new
ACP certificate. The details depend on the mechanisms/protocols used ACP certificate. The details depend on the mechanisms/protocols used
by the ACP Registrars. by the ACP Registrars.
Please refer to Section 6.10.7 and Please refer to Section 6.11.7 and
[I-D.ietf-anima-bootstrapping-keyinfra] for explanations about ACP [I-D.ietf-anima-bootstrapping-keyinfra] for explanations about ACP
Registrars and vouchers as used in the following text. When ACP is Registrars and vouchers as used in the following text. When ACP is
intended to be used without BRSKI, the details about BRSKI and intended to be used without BRSKI, the details about BRSKI and
vouchers in the following text can be skipped. vouchers in the following text can be skipped.
When BRSKI is used (i.e.: on ACP nodes that are ANI nodes), the re- When BRSKI is used (i.e.: on ACP nodes that are ANI nodes), the re-
enrolling candidate ACP node would attempt to enroll like a candidate enrolling candidate ACP node would attempt to enroll like a candidate
ACP node (BRSKI pledge), but instead of using the ACP nodes IDevID ACP node (BRSKI pledge), but instead of using the ACP nodes IDevID
certificate, it SHOULD first attempt to use its ACP domain certificate, it SHOULD first attempt to use its ACP domain
certificate in the BRSKI TLS authentication. The BRSKI registrar MAY certificate in the BRSKI TLS authentication. The BRSKI registrar MAY
skipping to change at page 39, line 9 skipping to change at page 39, line 23
its IDevID certificate as defined in BRSKI during the TLS connection its IDevID certificate as defined in BRSKI during the TLS connection
setup. setup.
Both when the BRSKI connection is attempted with the old ACP Both when the BRSKI connection is attempted with the old ACP
certificate or the IDevID certificate, the re-enrolling candidate ACP certificate or the IDevID certificate, the re-enrolling candidate ACP
node SHOULD authenticate the BRSKI registrar during TLS connection node SHOULD authenticate the BRSKI registrar during TLS connection
setup based on its existing TA certificate chain information setup based on its existing TA certificate chain information
associated with its old ACP certificate. The re-enrolling candidate associated with its old ACP certificate. The re-enrolling candidate
ACP node SHOULD only fall back to requesting a voucher from the BRSKI ACP node SHOULD only fall back to requesting a voucher from the BRSKI
registrar when this authentication fails during TLS connection setup. registrar when this authentication fails during TLS connection setup.
To prohibit attacks that attempt to force the ACP node to forget its
prior (expired) certificate and TA, the ACP node should alternate
between attempting to re-enroll using its old keying material and
attempting to re-enroll with its IDevID and requesting a voucher.
When other mechanisms than BRSKI are used for ACP certificate When other mechanisms than BRSKI are used for ACP certificate
enrollment, the principles of the re-enrolling candidate ACP node are enrollment, the principles of the re-enrolling candidate ACP node are
the same. The re-enrolling candidate ACP node attempts to the same. The re-enrolling candidate ACP node attempts to
authenticate any ACP Registrar peers during re-enrollment protocol/ authenticate any ACP Registrar peers during re-enrollment protocol/
mechanisms via its existing certificate chain/TA information and mechanisms via its existing certificate chain/TA information and
provides its existing ACP certificate and other identification (such provides its existing ACP certificate and other identification (such
as the IDevID certificate) as necessary to the registrar. as the IDevID certificate) as necessary to the registrar.
Maintaining existing TA information is especially important when Maintaining existing TA information is especially important when
enrollment mechanisms are used that unlike BRSKI do not leverage a enrollment mechanisms are used that unlike BRSKI do not leverage a
voucher mechanism to authenticate the ACP registrar and where mechanism (such as the voucher in BRSKI) to authenticate the ACP
therefore the injection of certificate failures could otherwise make registrar and where therefore the injection of certificate failures
the ACP node easily attackable remotely. could otherwise make the ACP node easily attackable remotely by
returning the ACP node to a "duckling" state in which it accepts to
be enrolled by any network it connects to. The (expired) ACP
certificate and ACP TA SHOULD therefore be maintained and used for
re-enrollment until new keying material is enrolled.
When using BRSKI or other protocol/mechanisms supporting vouchers, When using BRSKI or other protocol/mechanisms supporting vouchers,
maintaining existing TA information allows for re-enrollment of maintaining existing TA information allows for re-enrollment of
expired ACP certificates to be more lightweight, especially in expired ACP certificates to be more lightweight, especially in
environments where repeated acquisition of vouchers during the environments where repeated acquisition of vouchers during the
lifetime of ACP nodes may be operationally expensive or otherwise lifetime of ACP nodes may be operationally expensive or otherwise
undesirable. undesirable.
6.1.5.6. Failing Certificates 6.2.5.6. Failing Certificates
An ACP certificate is called failing in this document, if/when the An ACP certificate is called failing in this document, if/when the
ACP node to which the certificate was issued can determine that it ACP node to which the certificate was issued can determine that it
was revoked (or explicitly not renewed), or in the absence of such was revoked (or explicitly not renewed), or in the absence of such
explicit local diagnostics, when the ACP node fails to connect to explicit local diagnostics, when the ACP node fails to connect to
other ACP nodes in the same ACP domain using its ACP certificate. other ACP nodes in the same ACP domain using its ACP certificate.
For connection failures to determine the ACP certificate as the For connection failures to determine the ACP certificate as the
culprit, the peer should pass the domain membership check culprit, the peer should pass the domain membership check
(Section 6.1.3) and other reasons for the connection failure can be (Section 6.2.3) and other reasons for the connection failure can be
excluded because of the connection error diagnostics. excluded because of the connection error diagnostics.
This type of failure can happen during setup/refresh of a secure ACP This type of failure can happen during setup/refresh of a secure ACP
channel connections or any other use of the ACP certificate, such as channel connections or any other use of the ACP certificate, such as
for the TLS connection to an EST server for the renewal of the ACP for the TLS connection to an EST server for the renewal of the ACP
domain certificate. domain certificate.
Example reasons for failing certificates that the ACP node can only Example reasons for failing certificates that the ACP node can only
discover through connection failure are that the domain certificate discover through connection failure are that the domain certificate
or any of its signing certificates could have been revoked or may or any of its signing certificates could have been revoked or may
have expired, but the ACP node cannot self-diagnose this condition have expired, but the ACP node cannot self-diagnose this condition
directly. Revocation information or clock synchronization may only directly. Revocation information or clock synchronization may only
be available across the ACP, but the ACP node cannot build ACP secure be available across the ACP, but the ACP node cannot build ACP secure
channels because ACP peers reject the ACP node's domain certificate. channels because ACP peers reject the ACP node's domain certificate.
ACP nodes SHOULD support the option to determines whether its ACP ACP nodes SHOULD support the option to determines whether its ACP
certificate is failing, and when it does, put itself into the role of certificate is failing, and when it does, put itself into the role of
a re-enrolling candidate ACP node as explained above a re-enrolling candidate ACP node as explained above
(Section 6.1.5.5). (Section 6.2.5.5).
6.2. ACP Adjacency Table 6.3. ACP Adjacency Table
To know to which nodes to establish an ACP channel, every ACP node To know to which nodes to establish an ACP channel, every ACP node
maintains an adjacency table. The adjacency table contains maintains an adjacency table. The adjacency table contains
information about adjacent ACP nodes, at a minimum: Node-ID information about adjacent ACP nodes, at a minimum: Node-ID
(identifier of the node inside the ACP, see Section 6.10.3 and (identifier of the node inside the ACP, see Section 6.11.3 and
Section 6.10.5), interface on which neighbor was discovered (by GRASP Section 6.11.5), interface on which neighbor was discovered (by GRASP
as explained below), link-local IPv6 address of neighbor on that as explained below), link-local IPv6 address of neighbor on that
interface, certificate (including acp-node-name). An ACP node MUST interface, certificate (including acp-node-name). An ACP node MUST
maintain this adjacency table. This table is used to determine to maintain this adjacency table. This table is used to determine to
which neighbor an ACP connection is established. which neighbor an ACP connection is established.
Where the next ACP node is not directly adjacent (i.e., not on a link Where the next ACP node is not directly adjacent (i.e., not on a link
connected to this node), the information in the adjacency table can connected to this node), the information in the adjacency table can
be supplemented by configuration. For example, the Node-ID and IP be supplemented by configuration. For example, the Node-ID and IP
address could be configured. See Section 8.2. address could be configured. See Section 8.2.
The adjacency table MAY contain information about the validity and The adjacency table MAY contain information about the validity and
trust of the adjacent ACP node's certificate. However, subsequent trust of the adjacent ACP node's certificate. However, subsequent
steps MUST always start with the ACP domain membership check against steps MUST always start with the ACP domain membership check against
the peer (see Section 6.1.3). the peer (see Section 6.2.3).
The adjacency table contains information about adjacent ACP nodes in The adjacency table contains information about adjacent ACP nodes in
general, independently of their domain and trust status. The next general, independently of their domain and trust status. The next
step determines to which of those ACP nodes an ACP connection should step determines to which of those ACP nodes an ACP connection should
be established. be established.
6.3. Neighbor Discovery with DULL GRASP 6.4. Neighbor Discovery with DULL GRASP
[RFC Editor: GRASP draft is in RFC editor queue, waiting for [RFC Editor: GRASP draft is in RFC editor queue, waiting for
dependencies, including ACP. Please ensure that references to I- dependencies, including ACP. Please ensure that references to I-
D.ietf-anima-grasp that include section number references (throughout D.ietf-anima-grasp that include section number references (throughout
this document) will be updated in case any last-minute changes in this document) will be updated in case any last-minute changes in
GRASP would make those section references change. GRASP would make those section references change.
Discovery Unsolicited Link-Local (DULL) GRASP is a limited subset of Discovery Unsolicited Link-Local (DULL) GRASP is a limited subset of
GRASP intended to operate across an insecure link-local scope. See GRASP intended to operate across an insecure link-local scope. See
section 2.5.2 of [I-D.ietf-anima-grasp] for its formal definition. section 2.5.2 of [I-D.ietf-anima-grasp] for its formal definition.
skipping to change at page 41, line 21 skipping to change at page 41, line 44
interfaces MUST be limited so that at first only IPv6 StateLess interfaces MUST be limited so that at first only IPv6 StateLess
Address Auto Configuration (SLAAC - [RFC4862]) and DULL GRASP work Address Auto Configuration (SLAAC - [RFC4862]) and DULL GRASP work
and then only the following ACP secure channel setup packets - but and then only the following ACP secure channel setup packets - but
not any other unnecessary traffic (e.g., no other link-local IPv6 not any other unnecessary traffic (e.g., no other link-local IPv6
transport stack responders for example). transport stack responders for example).
Note that the use of the IPv6 link-local multicast address Note that the use of the IPv6 link-local multicast address
(ALL_GRASP_NEIGHBORS) implies the need to use Multicast Listener (ALL_GRASP_NEIGHBORS) implies the need to use Multicast Listener
Discovery Version 2 (MLDv2, see [RFC3810]) to announce the desire to Discovery Version 2 (MLDv2, see [RFC3810]) to announce the desire to
receive packets for that address. Otherwise DULL GRASP could fail to receive packets for that address. Otherwise DULL GRASP could fail to
operate correctly in the presence of MLD snooping, non-ACP enabled L2 operate correctly in the presence of MLD snooping ([RFC4541])
switches ([RFC4541]) - because those would stop forwarding DULL GRASP switches that are not ACP supporting/enabled - because those switches
packets. Switches not supporting MLD snooping simply need to operate would stop forwarding DULL GRASP packets. Switches not supporting
as pure L2 bridges for IPv6 multicast packets for DULL GRASP to work. MLD snooping simply need to operate as pure L2 bridges for IPv6
multicast packets for DULL GRASP to work.
ACP discovery SHOULD NOT be enabled by default on non-native ACP discovery SHOULD NOT be enabled by default on non-native
interfaces. In particular, ACP discovery MUST NOT run inside the ACP interfaces. In particular, ACP discovery MUST NOT run inside the ACP
across ACP virtual interfaces. See Section 9.3 for further, non- across ACP virtual interfaces. See Section 9.3 for further, non-
normative suggestions on how to enable/disable ACP at node and normative suggestions on how to enable/disable ACP at node and
interface level. See Section 8.2.2 for more details about tunnels interface level. See Section 8.2.2 for more details about tunnels
(typical non-native interfaces). See Section 7 for how ACP should be (typical non-native interfaces). See Section 7 for how ACP should be
extended on devices operating (also) as L2 bridges. extended on devices operating (also) as L2 bridges.
Note: If an ACP node also implements BRSKI to enroll its ACP Note: If an ACP node also implements BRSKI to enroll its ACP
skipping to change at page 42, line 5 skipping to change at page 42, line 26
discover both a bootstrap proxy and ACP neighbor at the same time. discover both a bootstrap proxy and ACP neighbor at the same time.
An ACP node announces itself to potential ACP peers by use of the An ACP node announces itself to potential ACP peers by use of the
"AN_ACP" objective. This is a synchronization objective intended to "AN_ACP" objective. This is a synchronization objective intended to
be flooded on a single link using the GRASP Flood Synchronization be flooded on a single link using the GRASP Flood Synchronization
(M_FLOOD) message. In accordance with the design of the Flood (M_FLOOD) message. In accordance with the design of the Flood
message, a locator consisting of a specific link-local IP address, IP message, a locator consisting of a specific link-local IP address, IP
protocol number and port number will be distributed with the flooded protocol number and port number will be distributed with the flooded
objective. An example of the message is informally: objective. An example of the message is informally:
[M_FLOOD, 12340815, h'fe80000000000000c0011001feef0000', 210000, [M_FLOOD, 12340815, h'fe80000000000000c0011001feef0000', 210000,
[["AN_ACP", 4, 1, "IKEv2" ], [["AN_ACP", 4, 1, "IKEv2" ],
[O_IPv6_LOCATOR, [O_IPv6_LOCATOR,
h'fe80000000000000c0011001feef0000', IPPROTO_UDP, 15000]] h'fe80000000000000c0011001feef0000', IPPROTO_UDP, 15000]]
[["AN_ACP", 4, 1, "DTLS" ], [["AN_ACP", 4, 1, "DTLS" ],
[O_IPv6_LOCATOR, [O_IPv6_LOCATOR,
h'fe80000000000000c0011001feef0000', IPPROTO_UDP, 17000]] h'fe80000000000000c0011001feef0000', IPPROTO_UDP, 17000]]
] ]
Figure 5: GRASP AN_ACP example Figure 6: GRASP AN_ACP example
The formal CDDL definition is: The formal CDDL definition is:
flood-message = [M_FLOOD, session-id, initiator, ttl, flood-message = [M_FLOOD, session-id, initiator, ttl,
+[objective, (locator-option / [])]] +[objective, (locator-option / [])]]
objective = ["AN_ACP", objective-flags, loop-count, objective = ["AN_ACP", objective-flags, loop-count,
objective-value] objective-value]
objective-flags = sync-only ; as in the GRASP specification objective-flags = sync-only ; as in the GRASP specification
sync-only = 4 ; M_FLOOD only requires synchronization sync-only = 4 ; M_FLOOD only requires synchronization
loop-count = 1 ; limit to link-local operation loop-count = 1 ; limit to link-local operation
objective-value = method objective-value = method / [ method, extensions ]
method = "IKEv2" / "DTLS" ; or future standard methods extensions = 1*any
method = method-name / [ method-name, method-params]
method-name = "IKEv2" / "DTLS" | any
method-params = 1*any
Figure 6: GRASP AN_ACP definition Figure 7: GRASP AN_ACP definition
The objective-flags field is set to indicate synchronization. The objective-flags field is set to indicate synchronization.
The loop-count is fixed at 1 since this is a link-local operation. The loop-count is fixed at 1 since this is a link-local operation.
In the above example the RECOMMENDED period of sending of the In the above example the RECOMMENDED period of sending of the
objective is 60 seconds. The indicated ttl of 210000 msec means that objective is 60 seconds. The indicated ttl of 210000 msec means that
the objective would be cached by ACP nodes even when two out of three the objective would be cached by ACP nodes even when two out of three
messages are dropped in transit. messages are dropped in transit.
The session-id is a random number used for loop prevention The session-id is a random number used for loop prevention
(distinguishing a message from a prior instance of the same message). (distinguishing a message from a prior instance of the same message).
In DULL this field is irrelevant but has to be set according to the In DULL this field is irrelevant but has to be set according to the
GRASP specification. GRASP specification.
The originator MUST be the IPv6 link local address of the originating The originator MUST be the IPv6 link local address of the originating
ACP node on the sending interface. ACP node on the sending interface.
The 'objective-value' parameter is a string indicating the protocol The method-name in the 'objective-value' parameter is a string
available at the specified or implied locator. It is a protocol indicating the protocol available at the specified or implied
supported by the node to negotiate a secure channel. IKEv2 as shown locator. It is a protocol supported by the node to negotiate a
above is the protocol used to negotiate an IPsec secure channel. secure channel. IKEv2 as shown above is the protocol used to
negotiate an IPsec secure channel.
Method-params allows to carry method specific parameters. This
specification does not define any method-params for "IKEv2" or
"DTLS". Method-params for these two methods that are not understood
by an ACP node MUST be ignored by it.
extensions allows to define method independent parameters. This
specification does not define any extensions. Extensions not
understood by an ACP node MUST be ignored by it.
The locator-option is optional and only required when the secure The locator-option is optional and only required when the secure
channel protocol is not offered at a well-defined port number, or if channel protocol is not offered at a well-defined port number, or if
there is no well-defined port number. there is no well-defined port number.
IKEv2 is the actual protocol used to negotiate an Internet Protocol IKEv2 is the actual protocol used to negotiate an Internet Protocol
security architecture (IPsec) connection. GRASP therefore indicates security architecture (IPsec) connection. GRASP therefore indicates
"IKEv2" and not "IPsec". If "IPsec" was used, this too could mean "IKEv2" and not "IPsec". If "IPsec" was used, this too could mean
use of the obsolete older version IKE (v1) ([RFC2409]). IKEv2 has an use of the obsolete older version IKE (v1) ([RFC2409]). IKEv2 has an
IANA assigned port number 500, but in the above example, the IANA assigned port number 500, but in the above example, the
candidate ACP neighbor is offering ACP secure channel negotiation via candidate ACP neighbor is offering ACP secure channel negotiation via
IKEv2 on port 15000 (purely to show through the example that GRASP IKEv2 on port 15000 (purely to show through the example that GRASP
allows to indicate the port number and it does not have to be the allows to indicate the port number and it does not have to be the
IANA assigned one). IANA assigned one).
"DTLS" indicates DTLS 1.2. This can also be a newer version of the There is no default UDP port for DTLS, it is always locally assigned
protocol as long as it can negotiate down to version 1.2 in the by the node. For further details about the "DTLS" secure channel
presence of a peer only speaking DTLS 1.2. There is no default UDP protocol, see Section 6.8.4.
port for DTLS, it is always locally assigned by the node. For
details, see Section 6.7.4.
If a locator is included, it MUST be an O_IPv6_LOCATOR, and the IPv6 If a locator is included, it MUST be an O_IPv6_LOCATOR, and the IPv6
address MUST be the same as the initiator address (these are DULL address MUST be the same as the initiator address (these are DULL
requirements to minimize third party DoS attacks). requirements to minimize third party DoS attacks).
The secure channel methods defined in this document use the The secure channel methods defined in this document use the
objective-values of "IKEv2" and "DTLS". There is no distinction objective-values of "IKEv2" and "DTLS". There is no distinction
between IKEv2 native and GRE-IKEv2 because this is purely negotiated between IKEv2 native and GRE-IKEv2 because this is purely negotiated
via IKEv2. via IKEv2.
A node that supports more than one secure channel protocol method A node that supports more than one secure channel protocol method
needs to flood multiple versions of the "AN_ACP" objective so that needs to flood multiple versions of the "AN_ACP" objective so that
each method can be accompanied by its own locator-option. This can each method can be accompanied by its own locator-option. This can
use a single GRASP M_FLOOD message as shown in Figure 5. use a single GRASP M_FLOOD message as shown in Figure 6.
The use of DULL GRASP primarily serves to discover the link-local
IPv6 address of candidate ACP peers on subnets. The signaling of the
supported secure channel option is primarily for diagnostic purposes,
but it is also necessary for discovery when the protocol has no well-
known transport address, such as in the case of DTLS.
Attackers on a subnet may be able to inject malicious DULL GRASP
messages that are indistinguishable from non-malicious DULL GRASP
messages to create Denial-of-Service (DoS) attacks that force ACP
nodes to attempt many unsuccessful ACP secure channel connections.
When an ACP node sees multiple AN_ACP objectives for the same secure
channel protocol on different transport addresses, it SHOULD prefer
connecting via the well-known transport address if the secure channel
method has one (such as UDP port 500 for IKEv2).
Note that a node serving both as an ACP node and BRSKI Join Proxy may Note that a node serving both as an ACP node and BRSKI Join Proxy may
choose to distribute the "AN_ACP" objective and the respective BRSKI choose to distribute the "AN_ACP" objective and the respective BRSKI
in the same M_FLOOD message, since GRASP allows multiple objectives in the same M_FLOOD message, since GRASP allows multiple objectives
in one message. This may be impractical though if ACP and BRSKI in one message. This may be impractical though if ACP and BRSKI
operations are implemented via separate software modules / ASAs. operations are implemented via separate software modules / ASAs.
The result of the discovery is the IPv6 link-local address of the The result of the discovery is the IPv6 link-local address of the
neighbor as well as its supported secure channel protocols (and non- neighbor as well as its supported secure channel protocols (and non-
standard port they are running on). It is stored in the ACP standard port they are running on). It is stored in the ACP
Adjacency Table (see Section 6.2), which then drives the further Adjacency Table (see Section 6.3), which then drives the further
building of the ACP to that neighbor. building of the ACP to that neighbor.
Note that the DULL GRASP objective described intentionally does not Note that the DULL GRASP objective described intentionally does not
include ACP nodes ACP certificate even though this would be useful include the ACP node's ACP certificate even though this would be
for diagnostics and to simplify the security exchange in ACP secure useful for diagnostics and to simplify the security exchange in ACP
channel security association protocols (see Section 6.7). The reason secure channel security association protocols (see Section 6.8). The
is that DULL GRASP messages are periodically multicasted across IPv6 reason is that DULL GRASP messages are periodically multicasted
subnets and full certificates could easily lead to fragmented IPv6 across IPv6 subnets and full certificates could easily lead to
DULL GRASP multicast packets due to the size of a certificate. This fragmented IPv6 DULL GRASP multicast packets due to the size of a
would be highly undesirable. certificate. This would be highly undesirable.
6.4. Candidate ACP Neighbor Selection 6.5. Candidate ACP Neighbor Selection
An ACP node determines to which other ACP nodes in the adjacency An ACP node determines to which other ACP nodes in the adjacency
table it should attempt to build an ACP connection. This is based on table it should attempt to build an ACP connection. This is based on
the information in the ACP Adjacency table. the information in the ACP Adjacency table.
The ACP is established exclusively between nodes in the same domain. The ACP is established exclusively between nodes in the same domain.
This includes all routing subdomains. Appendix A.7 explains how ACP This includes all routing subdomains. Appendix A.7 explains how ACP
connections across multiple routing subdomains are special. connections across multiple routing subdomains are special.
The result of the candidate ACP neighbor selection process is a list The result of the candidate ACP neighbor selection process is a list
of adjacent or configured autonomic neighbors to which an ACP channel of adjacent or configured autonomic neighbors to which an ACP channel
should be established. The next step begins that channel should be established. The next step begins that channel
establishment. establishment.
6.5. Channel Selection 6.6. Channel Selection
To avoid attacks, initial discovery of candidate ACP peers cannot To avoid attacks, initial discovery of candidate ACP peers cannot
include any non-protected negotiation. To avoid re-inventing and include any non-protected negotiation. To avoid re-inventing and
validating security association mechanisms, the next step after validating security association mechanisms, the next step after
discovering the address of a candidate neighbor can only be to try discovering the address of a candidate neighbor can only be to try
first to establish a security association with that neighbor using a first to establish a security association with that neighbor using a
well-known security association method. well-known security association method.
From the use-cases it seems clear that not all type of ACP nodes can From the use-cases it seems clear that not all type of ACP nodes can
or need to connect directly to each other or are able to support or or need to connect directly to each other or are able to support or
skipping to change at page 45, line 16 skipping to change at page 46, line 28
single common mandatory to implement (MTI) protocol, ACP nodes MUST single common mandatory to implement (MTI) protocol, ACP nodes MUST
try all the ACP secure channel protocols it supports and that are try all the ACP secure channel protocols it supports and that are
feasible because the candidate ACP neighbor also announced them via feasible because the candidate ACP neighbor also announced them via
its AN_ACP GRASP parameters (these are called the "feasible" ACP its AN_ACP GRASP parameters (these are called the "feasible" ACP
secure channel protocols). secure channel protocols).
To ensure that the selection of the secure channel protocols always To ensure that the selection of the secure channel protocols always
succeeds in a predictable fashion without blocking, the following succeeds in a predictable fashion without blocking, the following
rules apply: rules apply:
o An ACP node may choose to attempt to initiate the different * An ACP node may choose to attempt to initiate the different
feasible ACP secure channel protocols it supports according to its feasible ACP secure channel protocols it supports according to its
local policies sequentially or in parallel, but it MUST support local policies sequentially or in parallel, but it MUST support
acting as a responder to all of them in parallel. acting as a responder to all of them in parallel.
* Once the first ACP secure channel protocol connection to a
specific peer IPv6 address passes peer authentication, the two
peers know each other's certificate because those ACP certificates
are used by all secure channel protocols for mutual
authentication. The peer with the higher Node-ID in the
ACPNodeName of its ACP certificate takes on the role of the
Decider towards the peer. The other peer takes on the role of the
Follower. The Decider selects which secure channel protocol to
ultimately use.
* The Follower becomes passive: it does not attempt to further
initiate ACP secure channel protocol connections with the Decider
and does not consider it to be an error when the Decider closes
secure channels. The Decider becomes the active party, continues
to attempt setting up secure channel protocols with the Follower.
This process terminates when the Decider arrives at the "best" ACP
secure channel connection option that also works with the Follower
("best" from the Deciders point of view).
* A peer with a "0" acp-address in its AcpNodeName takes on the role
of Follower when peering with a node that has a non-"0" acp-
address (note that this specification does not fully define the
behavior of ACP secure channel negitation for nodes with a "0" ACP
address field, it only defines interoperability with such ACP
nodes).
o Once the first secure channel protocol succeeds, the two peers In a simple example, ACP peer Node 1 attempts to initiate an IPsec
know each other's certificates because they are used by all secure via IKEv2 connection to peer Node 2. The IKEv2 authentication
channel protocols for mutual authentication. The node with the succeeds. Node 1 has the lower ACP address and becomes the Follower.
lower Node-ID in the ACP address of its ACP certificate becomes Node 2 becomes the Decider. IKEv2 might not be the preferred ACP
Bob, the one with the higher Node-ID in the certificate Alice. A secure channel protocol for the Decider Node 2. Node 2 would
peer with an empty ACP address field in its ACP certificate therefore proceed to attempt secure channel setups with (in its view)
becomes Bob (this specification does not define such peers, only more preferred protocol options (e.g., DTLS/UDP). If any such
the interoperability with them). preferred ACP secure channel connection of the Decider succeeds, it
would close the IPsec connection. If Node 2 has no preferred
o Bob becomes passive, he does not attempt to further initiate ACP protocol option over IPsec, or no such connection attempt from Node 2
secure channel protocols with Alice and does not consider it to be to Node 1 succeeds, Node 2 would keep the IPsec connection and use
an error when Alice closes secure channels. Alice becomes the it.
active party, continues to attempt setting up secure channel
protocols with Bob until she arrives at the best one from her view
that also works with Bob.
For example, originally Bob could have been the initiator of one ACP The Decider SHOULD NOT send actual payload packets across a secure
secure channel protocol that Bob prefers and the security association channel until it has decided to use it. The Follower MAY delay
succeeded. The roles of Bob and Alice are then assigned and the linking the ACP secure channel into the ACP virtual interface until
connection setup is completed. The protocol could for example be it sees the first payload packet from the Decider up to a maximum of
IPsec via IKEv2 ("IP security", see [RFC4301] and "Internet Key 5 seconds to avoid unnecessarily linking a secure channel that will
Exchange protocol version 2", see [RFC7296]. It is now up to Alice be terminated as undesired by the Decider shortly afterwards.
to decide how to proceed. Even if the IPsec connection from Bob
succeeded, Alice might prefer another secure protocol over IPsec
(e.g., FOOBAR), and try to set that up with Bob. If that preference
of Alice succeeds, she would close the IPsec connection. If no
better protocol attempt succeeds, she would keep the IPsec
connection.
The following sequence of steps show this example in more detail. The following sequence of steps show this example in more detail.
Each step is tagged with [<step#>{:<connection>}]. The connection is Each step is tagged with [<step#>{:<connection>}]. The connection is
included to easier distinguish which of the two competing connections included to more easily distinguish which of the two competing
the step belong to, one initiated by Node 1, one initiated by Node 2. connections the step belong to, one initiated by Node 1, one
initiated by Node 2.
[1] Node 1 sends GRASP AN_ACP message to announce itself [1] Node 1 sends GRASP AN_ACP message to announce itself
[2] Node 2 sends GRASP AN_ACP message to announce itself [2] Node 2 sends GRASP AN_ACP message to announce itself
[3] Node 2 receives [1] from Node 1 [3] Node 2 receives [1] from Node 1
[4:C1] Because of [3], Node 2 starts as initiator on its [4:C1] Because of [3], Node 2 starts as initiator on its
preferred secure channel protocol towards Node 1. preferred secure channel protocol towards Node 1.
Connection C1. Connection C1.
[5] Node 1 receives [2] from Node 2 [5] Node 1 receives [2] from Node 2
[6:C2] Because of [5], Node 1 starts as initiator on its [6:C2] Because of [5], Node 1 starts as initiator on its
preferred secure channel protocol towards Node 2. preferred secure channel protocol towards Node 2.
Connection C2. Connection C2.
[7:C1] Node1 and Node2 have authenticated each others [7:C1] Node1 and Node2 have authenticated each others
certificate on connection C1 as valid ACP peers. certificate on connection C1 as valid ACP peers.
[8:C1] Node 1 certificate has lower ACP Node-ID than Node2, [8:C1] Node 1 certificate has lower ACP Node-ID than Node2, therefore
therefore Node 1 considers itself Bob and Node 2 Alice Node 1 considers itself the Follower and Node 2 the Decider
on connection C1. Connection setup C1 is completed. on connection C1. Connection setup C1 is completed.
[9] Node 1 (Bob)) refrains from attempting any further secure [9] Node 1 refrains from attempting any further secure channel
channel connections to Node 2 (Alice) as learned from [2] connections to Node 2 (the Decider) as learned from [2]
because it knows from [8:C1] that it is Bob relative because it knows from [8:C1] that it is the Follower
to Node 1. relative to Node 1.
[10:C2] Node1 and Node2 have authenticated each others [10:C2] Node1 and Node2 have authenticated each others
certificate on connection C2 (like [7:C1]). certificate on connection C2 (like [7:C1]).
[11:C2] Node 1 certificate has lower ACP Node-ID than Node2, [11:C2] Node 1 certificate has lower ACP Node-ID than Node2,
therefore Node 1 considers itself Bob and Node 2 Alice therefore Node 1 considers itself the Follower and Node 2 the
on connection C2, but they also identify that C2 is to the Decider on connection C2, but they also identify that C2 is
same mutual peer as their C1, so this has no further impact: to the same mutual peer as their C1, so this has no further
the roles Alice and Bob where already assigned between these impact: the roles Decider and Follower where already assigned
two peers by [8:C1]. between these two peers by [8:C1].
[12:C2] Node 2 (Alice) closes C1. Node 1 (Bob) is fine with this, [12:C2] Node 2 (the Decider) closes C1. Node 1 is fine with this,
because of his role as Bob (since [8:C1]). because of its role as the Follower (from [8:C1]).
[13] Node 2 (Alice) and Node 1 (Bob) start data transfer across [13] Node 2 (the Decider) and Node 1 (the Follower) start data
C2, which makes it become a secure channel for the ACP. transfer across C2, which makes it become a secure channel
for the ACP.
Figure 7: Secure Channel sequence of steps Figure 8: Secure Channel sequence of steps
All this negotiation is in the context of an "L2 interface". Alice All this negotiation is in the context of an "L2 interface". The
and Bob will build ACP connections to each other on every "L2 Decider and Follower will build ACP connections to each other on
interface" that they both connect to. An autonomic node MUST NOT every "L2 interface" that they both connect to. An autonomic node
assume that neighbors with the same L2 or link-local IPv6 addresses MUST NOT assume that neighbors with the same L2 or link-local IPv6
on different L2 interfaces are the same node. This can only be addresses on different L2 interfaces are the same node. This can
determined after examining the certificate after a successful only be determined after examining the certificate after a successful
security association attempt. security association attempt.
6.6. Candidate ACP Neighbor verification The Decider SHOULD NOT suppress attempting a particular ACP secure
channel protocol connection on one L2 interface because this type of
ACP secure channel connection has failed to the peer with the same
ACP certificate on another L2 interface: Not only the supported ACP
secure channel protocol options may be different on the same ACP peer
across different L2 interfaces, but also error conditions may cause
inconsistent failures across different L2 interfaces. Avoiding such
connection attempt optimizations can therefore help to increase
robustness in the case of errors.
6.7. Candidate ACP Neighbor verification
Independent of the security association protocol chosen, candidate Independent of the security association protocol chosen, candidate
ACP neighbors need to be authenticated based on their domain ACP neighbors need to be authenticated based on their domain
certificate. This implies that any secure channel protocol MUST certificate. This implies that any secure channel protocol MUST
support certificate based authentication that can support the ACP support certificate based authentication that can support the ACP
domain membership check as defined in Section 6.1.3. If it fails, domain membership check as defined in Section 6.2.3. If it fails,
the connection attempt is aborted and an error logged. Attempts to the connection attempt is aborted and an error logged. Attempts to
reconnect MUST be throttled. The RECOMMENDED default is exponential reconnect MUST be throttled. The RECOMMENDED default is exponential
base 2 backoff with a minimum delay of 10 seconds and a maximum delay base 2 backoff with an initial retransmission time (IRT) of 10
of 640 seconds. seconds and a maximum retransmission time (MRT) of 640 seconds.
Failure to authenticate an ACP neighbor when acting in the role of a Failure to authenticate an ACP neighbor when acting in the role of a
responder of the security authentication protocol MUST NOT impact the responder of the security authentication protocol MUST NOT impact the
attempts of the ACP node to attempt establishing a connection as an attempts of the ACP node to attempt establishing a connection as an
initiator. Only failed connection attempts as an initiator must initiator. Only failed connection attempts as an initiator must
cause throttling. This rule is meant to increase resilience of cause throttling. This rule is meant to increase resilience of
secure channel creation. Section 6.5 shows how simultaneous mutual secure channel creation. Section 6.6 shows how simultaneous mutual
secure channel setup collisions are resolved. secure channel setup collisions are resolved.
6.7. Security Association (Secure Channel) protocols 6.8. Security Association (Secure Channel) protocols
This section describes how ACP nodes establish secured data This section describes how ACP nodes establish secured data
connections to automatically discovered or configured peers in the connections to automatically discovered or configured peers in the
ACP. Section 6.3 above described how IPv6 subnet adjacent peers are ACP. Section 6.4 above described how IPv6 subnet adjacent peers are
discovered automatically. Section 8.2 describes how non IPv6 subnet discovered automatically. Section 8.2 describes how non IPv6 subnet
adjacent peers can be configured. adjacent peers can be configured.
Section 6.12.5.2 describes how secure channels are mapped to virtual Section 6.13.5.2 describes how secure channels are mapped to virtual
IPv6 subnet interfaces in the ACP. The simple case is to map every IPv6 subnet interfaces in the ACP. The simple case is to map every
ACP secure channel into a separate ACP point-to-point virtual ACP secure channel into a separate ACP point-to-point virtual
interface Section 6.12.5.2.1. When a single subnet has multiple ACP interface Section 6.13.5.2.1. When a single subnet has multiple ACP
peers this results in multiple ACP point-to-point virtual interfaces peers this results in multiple ACP point-to-point virtual interfaces
across that underlying multi-party IPv6 subnet. This can be across that underlying multi-party IPv6 subnet. This can be
optimized with ACP multi-access virtual interfaces Section 6.12.5.2.2 optimized with ACP multi-access virtual interfaces
but the benefits of that optimization may not justify the complexity (Section 6.13.5.2.2) but the benefits of that optimization may not
of that option. justify the complexity of that option.
6.7.1. General considerations 6.8.1. General considerations
Due to Channel Selection (Section 6.5), ACP can support an evolving Due to Channel Selection (Section 6.6), ACP can support an evolving
set of security association protocols and does not require support set of security association protocols and does not require support
for a single network wide MTI. ACP nodes only need to implement for a single network wide MTI. ACP nodes only need to implement
those protocols required to interoperate with their candidate peers, those protocols required to interoperate with their candidate peers,
not with potentially any node in the ACP domain. See Section 6.7.5 not with potentially any node in the ACP domain. See Section 6.8.5
for an example of this. for an example of this.
The degree of security required on every hop of an ACP network needs The degree of security required on every hop of an ACP network needs
to be consistent across the network so that there is no designated to be consistent across the network so that there is no designated
"weakest link" because it is that "weakest link" that would otherwise "weakest link" because it is that "weakest link" that would otherwise
become the designated point of attack. When the secure channel become the designated point of attack. When the secure channel
protection on one link is compromised, it can be used to send/receive protection on one link is compromised, it can be used to send/receive
packets across the whole ACP network. Therefore, even though the packets across the whole ACP network. Therefore, even though the
security association protocols can be different, their minimum degree security association protocols can be different, their minimum degree
of security should be comparable. of security should be comparable.
skipping to change at page 49, line 47 skipping to change at page 51, line 8
Strong physical security of a link may stand in where cryptographic Strong physical security of a link may stand in where cryptographic
security is infeasible. As there is no secure mechanism to security is infeasible. As there is no secure mechanism to
automatically discover strong physical security solely between two automatically discover strong physical security solely between two
peers, it can only be used with explicit configuration and that peers, it can only be used with explicit configuration and that
configuration too could become an attack vector. This document configuration too could become an attack vector. This document
therefore only specifies with ACP connect (Section 8.1) one therefore only specifies with ACP connect (Section 8.1) one
explicitly configured mechanism without any secure channel explicitly configured mechanism without any secure channel
association protocol - for the case where both the link and the nodes association protocol - for the case where both the link and the nodes
attached to it have strong physical security. attached to it have strong physical security.
6.7.2. Common requirements 6.8.2. Common requirements
The authentication of peers in any security association protocol MUST The authentication of peers in any security association protocol MUST
use the ACP certificate according to Section 6.1.3. Because auto- use the ACP certificate according to Section 6.2.3. Because auto-
discovery of candidate ACP neighbors via GRASP (see Section 6.3) as discovery of candidate ACP neighbors via GRASP (see Section 6.4) as
specified in this document does not communicate the neighbors ACP specified in this document does not communicate the neighbors ACP
certificate, and ACP nodes may not (yet) have any other network certificate, and ACP nodes may not (yet) have any other network
connectivity to retrieve certificates, any security association connectivity to retrieve certificates, any security association
protocol MUST use a mechanism to communicate the certificate directly protocol MUST use a mechanism to communicate the certificate directly
instead of relying on a referential mechanism such as communicating instead of relying on a referential mechanism such as communicating
only a hash and/or URL for the certificate. only a hash and/or URL for the certificate.
A security association protocol MUST use Forward Secrecy (whether A security association protocol MUST use Forward Secrecy (whether
inherently or as part of a profile of the security association inherently or as part of a profile of the security association
protocol). protocol).
skipping to change at page 51, line 10 skipping to change at page 52, line 20
options SHOULD be eliminated that are not necessary to support options SHOULD be eliminated that are not necessary to support
devices that are expected to be able to support the ACP to minimize devices that are expected to be able to support the ACP to minimize
implementation complexity. For example, definitions for security implementation complexity. For example, definitions for security
protocols often include old/inferior security options required only protocols often include old/inferior security options required only
to interoperate with existing devices that will not be a able to to interoperate with existing devices that will not be a able to
update to the currently preferred security options. Such old/ update to the currently preferred security options. Such old/
inferior security options do not need to be supported when a security inferior security options do not need to be supported when a security
association protocol is first specified for the ACP, strengthening association protocol is first specified for the ACP, strengthening
the "weakest link" and simplifying ACP implementation overhead. the "weakest link" and simplifying ACP implementation overhead.
6.7.3. ACP via IPsec 6.8.3. ACP via IPsec
An ACP node announces its ability to support IPsec, negotiated via An ACP node announces its ability to support IPsec, negotiated via
IKEv2, as the ACP secure channel protocol using the "IKEv2" IKEv2, as the ACP secure channel protocol using the "IKEv2"
objective-value in the "AN_ACP" GRASP objective. objective-value in the "AN_ACP" GRASP objective.
The ACP usage of IPsec and IKEv2 mandates a profile with a narrow set The ACP usage of IPsec and IKEv2 mandates a profile with a narrow set
of options of the current standards-track usage guidance for IPsec of options of the current standards-track usage guidance for IPsec
[RFC8221] and IKEv2 [RFC8247]. These option result in stringent [RFC8221] and IKEv2 [RFC8247]. These option result in stringent
security properties and can exclude deprecated/legacy algorithms security properties and can exclude deprecated/legacy algorithms
because there is no need for interoperability with legacy equipment because there is no need for interoperability with legacy equipment
for ACP secure channels. Any such backward compatibility would lead for ACP secure channels. Any such backward compatibility would lead
only to increased attack surface and implementation complexity, for only to increased attack surface and implementation complexity, for
no benefit. no benefit.
6.7.3.1. Native IPsec 6.8.3.1. Native IPsec
An ACP node that is supporting native IPsec MUST use IPsec in tunnel An ACP node that is supporting native IPsec MUST use IPsec in tunnel
mode, negotiated via IKEv2, and with IPv6 payload (e.g., ESP Next mode, negotiated via IKEv2, and with IPv6 payload (e.g., ESP Next
Header of 41). It MUST use local and peer link-local IPv6 addresses Header of 41). It MUST use local and peer link-local IPv6 addresses
for encapsulation. Manual keying MUST NOT be used, see Section 6.1. for encapsulation. Manual keying MUST NOT be used, see Section 6.2.
Traffic Selectors are: Traffic Selectors are:
TSi = (0, 0-65535, :: - FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF) TSi = (0, 0-65535, :: - FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF)
TSr = (0, 0-65535, :: - FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF) TSr = (0, 0-65535, :: - FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF)
IPsec tunnel mode is required because the ACP will route/forward IPsec tunnel mode is required because the ACP will route/forward
packets received from any other ACP node across the ACP secure packets received from any other ACP node across the ACP secure
channels, and not only its own generated ACP packets. With IPsec channels, and not only its own generated ACP packets. With IPsec
transport mode (and no additional encapsulation header in the ESP transport mode (and no additional encapsulation header in the ESP
payload), it would only be possible to send packets originated by the payload), it would only be possible to send packets originated by the
ACP node itself because the IPv6 addresses of the ESP must be the ACP node itself because the IPv6 addresses of the ESP must be the
same as that of the outer IPv6 header. same as that of the outer IPv6 header.
6.7.3.1.1. RFC8221 (IPsec/ESP) 6.8.3.1.1. RFC8221 (IPsec/ESP)
ACP IPsec implementations MUST comply with [RFC8221] (and its ACP IPsec implementations MUST comply with [RFC8221] (and its
updates). The requirements from above and this section amend and updates). The requirements from above and this section amend and
superseded its requirements. superseded its requirements.
AH MUST NOT be used (because it does not provide confidentiality). The IP Authentication Header (AH) MUST NOT be used (because it does
not provide confidentiality).
For the required ESP encryption algorithms in section 5 of [RFC8221] For the required ESP encryption algorithms in section 5 of [RFC8221]
the following guidance applies: the following guidance applies:
o ENCR_NULL AH MUST NOT be used (because it does not provide * ENCR_NULL AH MUST NOT be used (because it does not provide
confidentiality). confidentiality).
* ENCR_AES_GCM_16 is the only MTI ESP encryption algorithm for ACP
o ENCR_AES_GCM_16 is the only MTI ESP encryption algorithm for ACP
via IPsec/ESP (it is already listed as MUST in [RFC8221]). via IPsec/ESP (it is already listed as MUST in [RFC8221]).
* ENCR_AES_CBC with AUTH_HMAC_SHA2_256_128 (as the ESP
o ENCR_AES_CBC and ENCR_AES_CCM_8 MAY be supported. If either authentication algorithm) and ENCR_AES_CCM_8 MAY be supported. If
provides higher performance than ENCR_AES_GCM_16 it SHOULD be either provides higher performance than ENCR_AES_GCM_16 it SHOULD
supported. be supported.
* ENCR_CHACHA20_POLY1305 SHOULD be supported at equal or higher
o ENCR_CHACHA20_POLY1305 SHOULD be supported at equal or higher
performance than ENCR_AES_GCM_16. If that performance is not performance than ENCR_AES_GCM_16. If that performance is not
feasible, it MAY be supported. feasible, it MAY be supported.
IKEv2 indicates an order for the offered algorithms. The algorithms IKEv2 indicates an order for the offered algorithms. The algorithms
SHOULD be ordered by performance. The first algorithm supported by SHOULD be ordered by performance. The first algorithm supported by
both sides is generally choosen. both sides is generally choosen.
Explanations: Explanations:
o There is no requirement to interoperate with legacy equipment in * There is no requirement to interoperate with legacy equipment in
ACP secure channels, so a single MTI encryption algorithm for ACP secure channels, so a single MTI encryption algorithm for
IPsec in ACP secure channels is sufficient for interoperability IPsec in ACP secure channels is sufficient for interoperability
and allows for the most lightweight implementations. and allows for the most lightweight implementations.
* ENCR_AES_GCM_16 is an authenticated encryption with associated
o ENCR_AES_GCM_16 is an authenticated encryption with associated
data (AEAD) cipher mode, so no additional ESP authentication data (AEAD) cipher mode, so no additional ESP authentication
algorithm is needed, simplifying the MTI requirements of IPsec for algorithm is needed, simplifying the MTI requirements of IPsec for
the ACP. the ACP.
o There is no MTI requirement against support of ENCR_AES_CBC * There is no MTI requirement for the support of ENCR_AES_CBC
because ENCR_AES_GCM_16 is assumed to be feasible with less cost/ because ENCR_AES_GCM_16 is assumed to be feasible with less cost/
higher performance in modern devices hardware accelerated higher performance in modern devices hardware accelerated
implementations compared to ENCR-AES_CBC. implementations compared to ENCR-AES_CBC.
* ENCR_CHACHA20_POLY1305 is mandatory in [RFC8221] because of its
o ENCR_CHACHA20_POLY1305 is mandatory in [RFC8221] because of its
target use as a fallback algorithm in case weaknesses in AES are target use as a fallback algorithm in case weaknesses in AES are
uncoverered. Unfortunately, there is currently no way to uncoverered. Unfortunately, there is currently no way to
automatically propagate across an ACP a policy to disallow use of automatically propagate across an ACP a policy to disallow use of
AES based algorithms, so this target benefit of AES based algorithms, so this target benefit of
ENCR_CHACHA20_POLY1305 can not fully be adopted yet for the ACP. ENCR_CHACHA20_POLY1305 can not fully be adopted yet for the ACP.
Therefore this algorithm is only recommended. Changing from AES Therefore this algorithm is only recommended. Changing from AES
to this algorithm at potentially big drop in performance could to this algorithm at potentially big drop in performance could
also render the ACP inoperable. Therefore the performance also render the ACP inoperable. Therefore the performance
requirement against this algorithm so that it could become an requirement against this algorithm so that it could become an
effective security backup to AES for the ACP once a policy to effective security backup to AES for the ACP once a policy to
switch over to it or prefer it is available in an ACP framework. switch over to it or prefer it is available in an ACP framework.
[RFC8221] allows for 128-bit or 256-bit AES keys. This document [RFC8221] allows for 128-bit or 256-bit AES keys. This document
mandates that only 256-bit AES keys MUST be supported. mandates that only 256-bit AES keys MUST be supported.
When [RFC8221] is updated, ACP implementations will need to consider When [RFC8221] is updated, ACP implementations will need to consider
legacy interoperability, and the IPsec WG has generally done a very legacy interoperability, and the IPsec WG has generally done a very
good job of taking that into account in its recommendations. good job of taking that into account in its recommendations.
6.7.3.1.2. RFC8247 (IKEv2) 6.8.3.1.2. RFC8247 (IKEv2)
[RFC8247] provides a baseline recommendation for mandatory to [RFC8247] provides a baseline recommendation for mandatory to
implement ciphers, integrity checks, pseudo-random-functions and implement ciphers, integrity checks, pseudo-random-functions and
Diffie-Hellman mechanisms. Those recommendations, and the Diffie-Hellman mechanisms. Those recommendations, and the
recommendations of subsequent documents apply well to the ACP. recommendations of subsequent documents apply well to the ACP.
Because IKEv2 for ACP secure channels is sufficient to be implemented Because IKEv2 for ACP secure channels is sufficient to be implemented
in control plane software, rather than in ASIC hardware, and ACP in control plane software, rather than in ASIC hardware, and ACP
nodes supporting IKEv2 are not assumed to be code-space constrained, nodes supporting IKEv2 are not assumed to be code-space constrained,
and because existing IKEv2 implementations are expected to support and because existing IKEv2 implementations are expected to support
[RFC8247] recommendations, this documents makes no attempt to [RFC8247] recommendations, this documents makes no attempt to
simplify its recommendations for use with the ACP. simplify its recommendations for use with the ACP.
See [IKEV2IANA] for IANA IKEv2 parameter names used in this text. See [IKEV2IANA] for IANA IKEv2 parameter names used in this text.
ACP Nodes supporting IKEv2 MUST comply with [RFC8247] amended by the ACP Nodes supporting IKEv2 MUST comply with [RFC8247] amended by the
following requirements which constitute a policy statement as following requirements which constitute a policy statement as
permitted by [RFC8247]. permitted by [RFC8247].
To signal the ACP certificate chain (including TA) as required by To signal the ACP certificate chain (including TA) as required by
Section 6.7.2, "X.509 Certificate - Signature" payload in IKEv2 can Section 6.8.2, "X.509 Certificate - Signature" payload in IKEv2 can
be used. It is mandatory according to [RFC7296] section 3.6. be used. It is mandatory according to [RFC7296] section 3.6.
ACP nodes SHOULD set up IKEv2 to only use the ACP certificate and TA ACP nodes SHOULD set up IKEv2 to only use the ACP certificate and TA
when acting as an IKEv2 responder on the IPv6 link local address and when acting as an IKEv2 responder on the IPv6 link local address and
port number indicated in the AN_ACP DULL GRASP announcements (see port number indicated in the AN_ACP DULL GRASP announcements (see
Section 6.3). Section 6.4).
When CERTREQ is received from a peer, and does not indicate any of When CERTREQ is received from a peer, and does not indicate any of
this ACP nodes TA certificates, the ACP node SHOULD ignore the this ACP nodes TA certificates, the ACP node SHOULD ignore the
CERTREQ and continue sending its certificate chain including its TA CERTREQ and continue sending its certificate chain including its TA
as subject to the requirements and explanations in Section 6.7.2. as subject to the requirements and explanations in Section 6.8.2.
This will not result in successful mutual authentication but assists This will not result in successful mutual authentication but assists
diagnostics. diagnostics.
Note that with IKEv2, failing authentication will only result in the Note that with IKEv2, failing authentication will only result in the
responder receiving the certificate chain from the initiator, but not responder receiving the certificate chain from the initiator, but not
vice versa. Because ACP secure channel setup is symmetric (see vice versa. Because ACP secure channel setup is symmetric (see
Section 6.6), every non-malicious ACP neighbor will attempt to Section 6.7), every non-malicious ACP neighbor will attempt to
connect as an initiator though, allowing to obtain the diagnostic connect as an initiator though, allowing to obtain the diagnostic
information about the neighbors certificate. information about the neighbors certificate.
In IKEv2, ACP nodes are identified by their ACP address. The In IKEv2, ACP nodes are identified by their ACP address. The
ID_IPv6_ADDR IKEv2 identification payload MUST be used and MUST ID_IPv6_ADDR IKEv2 identification payload MUST be used and MUST
convey the ACP address. If the peer's ACP certificate includes a convey the ACP address. If the peer's ACP certificate includes a
32HEXLC ACP address in the acp-node-name (not "0" or empty), the 32HEXDIG ACP address in the acp-node-name (not "0" or omitted), the
address in the IKEv2 identification payload MUST match it. See address in the IKEv2 identification payload MUST match it. See
Section 6.1.3 for more information about "0" or empty ACP address Section 6.2.3 for more information about "0" or omitted ACP address
fields in the acp-node-name. fields in the acp-node-name.
IKEv2 authentication MUST use authentication method 14 ("Digital IKEv2 authentication MUST use authentication method 14 ("Digital
Signature") for ACP certificates; this authentication method can be Signature") for ACP certificates; this authentication method can be
used with both RSA and ECDSA certificates, indicated by an ASN.1 used with both RSA and ECDSA certificates, indicated by an ASN.1
object AlgorithmIdentifier. object AlgorithmIdentifier.
The Digital Signature hash SHA2-512 MUST be supported (in addition to The Digital Signature hash SHA2-512 MUST be supported (in addition to
SHA2-256). SHA2-256).
The IKEv2 Diffie-Hellman key exchange group 19 (256-bit random ECP), The IKEv2 Diffie-Hellman key exchange group 19 (256-bit random ECP),
listed as a SHOULD, is to be configured, along with the 2048-bit MODP MUST be support. Reason: ECC provides a similar security level to
(group 14). ECC provides a similar security level to finite-field finite-field (MODP) key exchange with a shorter key length, so is
(MODP) key exchange with a shorter key length, so is generally generally preferred absent other considerations.
preferred absent other considerations.
6.7.3.2. IPsec with GRE encapsulation 6.8.3.2. IPsec with GRE encapsulation
In network devices it is often more common to implement high In network devices it is often more common to implement high
performance virtual interfaces on top of GRE encapsulation than on performance virtual interfaces on top of GRE encapsulation than on
top of a "native" IPsec association (without any other encapsulation top of a "native" IPsec association (without any other encapsulation
than those defined by IPsec). On those devices it may be beneficial than those defined by IPsec). On those devices it may be beneficial
to run the ACP secure channel on top of GRE protected by the IPsec to run the ACP secure channel on top of GRE protected by the IPsec
association. association.
The requirements for ESP/IPsec/IKEv2 with GRE are the same as for The requirements for ESP/IPsec/IKEv2 with GRE are the same as for
native IPsec (see Section 6.7.3.1) except that IPsec transport mode native IPsec (see Section 6.8.3.1) except that IPsec transport mode
and next protocol GRE (47) are to be negotiated. Tunnel mode is not and next protocol GRE (47) are to be negotiated. Tunnel mode is not
required because of GRE. Traffic Selectors are: required because of GRE. Traffic Selectors are:
TSi = (47, 0-65535, Initiator-IPv6-LL-addr ... Initiator-ACP-LL-addr) TSi = (47, 0-65535, Initiator-IPv6-LL-addr ... Initiator-IPv6-LL-
addr)
TSr = (47, 0-65535, Responder-IPv6-LL-addr ... Responder-IPv6-LL- TSr = (47, 0-65535, Responder-IPv6-LL-addr ... Responder-IPv6-LL-
addr) addr)
If IKEv2 initiator and responder support IPsec over GRE, it has to be If IKEv2 initiator and responder support IPsec over GRE, it will be
preferred over native IPsec. The ACP IPv6 traffic has to be carried preferred over native IPsec because of the way how IKEv2 negotiates
across GRE according to [RFC7676]. transport mode as used by this IPsec over GRE profile) versus tunnel
mode as used by native IPsec (see [RFC7296], section 1.3.1). The ACP
IPv6 traffic has to be carried across GRE according to [RFC7676].
6.7.4. ACP via DTLS 6.8.4. ACP via DTLS
We define the use of ACP via DTLS in the assumption that it is likely This document defines the use of ACP via DTLS, on the assumption that
the first transport encryption supported in some classes of it is likely the first transport encryption supported in some classes
constrained devices because DTLS is already used in those devices but of constrained devices: DTLS is commonly used in constrained devices
IPsec is not, and code-space may be limited. when IPsec is not. Code-space on those devices may be also be too
limited to support more than the minimum number of required
protocols.
An ACP node announces its ability to support DTLS v1.2 compliant with An ACP node announces its ability to support DTLS version 1.2
the requirements defined in this document as an ACP secure channel ([RFC6347]) compliant with the requirements defined in this document
protocol in GRASP through the "DTLS" objective-value in the "AN_ACP" as an ACP secure channel protocol in GRASP through the "DTLS"
objective. objective-value in the "AN_ACP" objective (see Section 6.4).
To run ACP via UDP and DTLS v1.2 [RFC6347], a locally assigned UDP To run ACP via UDP and DTLS, a locally assigned UDP port is used that
port is used that is announced as a parameter in the GRASP AN_ACP is announced as a parameter in the GRASP AN_ACP objective to
objective to candidate neighbors. This port can also be any newer candidate neighbors. This port can also be any newer version of DTLS
version of DTLS as long as that version can negotiate a DTLS v1.2 as long as that version can negotiate a DTLS v1.2 connection in the
connection in the presence of an DTLS v1.2 only peer. presence of an DTLS v1.2 only peer.
All ACP nodes supporting DTLS as a secure channel protocol MUST All ACP nodes supporting DTLS as a secure channel protocol MUST
adhere to the DTLS implementation recommendations and security adhere to the DTLS implementation recommendations and security
considerations of BCP 195 [RFC7525] except with respect to the DTLS considerations of BCP 195, BCP 195 [RFC7525] except with respect to
version. ACP nodes supporting DTLS MUST support DTLS 1.2. They MUST the DTLS version. ACP nodes supporting DTLS MUST support DTLS 1.2.
NOT support older versions of DTLS. Implementation MUST comply with They MUST NOT support older versions of DTLS.
BCP 195, [RFC7525].
Unlike for IPsec, no attempts are made to simplify the requirements Unlike for IPsec, no attempts are made to simplify the requirements
of the BCP 195 recommendations because the expectation is that DTLS of the BCP 195 recommendations because the expectation is that DTLS
would be using software-only implementations where the ability to would be using software-only implementations where the ability to
reuse of widely adopted implementations is more important than reuse of widely adopted implementations is more important than
minizing the complexity of a hardware accelerated implementation minizing the complexity of a hardware accelerated implementation
which is known to be important for IPsec. which is known to be important for IPsec.
DTLS v1.3 ([I-D.ietf-tls-dtls13]) is "backward compatible" with DTLS DTLS v1.3 ([I-D.ietf-tls-dtls13]) is "backward compatible" with DTLS
v1.2 (see section 1. of DTLS v1.3): A DTLS implementation supporting v1.2 (see section 1. of DTLS v1.3). A DTLS implementation supporting
both DTLS v1.2 and DTLS v1.3 does comply with the above requirements both DTLS v1.2 and DTLS v1.3 does comply with the above requirements
of negoting to DTLS v1.2 in the presence of a DTLS v1.2 only peer, of negotiating to DTLS v1.2 in the presence of a DTLS v1.2 only peer,
but using DTLS v1.3 when booth peers support it. but using DTLS v1.3 when booth peers support it.
Version v1.2 is the MTI version of DTLS in this specification because Version v1.2 is the MTI version of DTLS in this specification because
o There is more experience with DTLS v1.2 across the spectrum of * There is more experience with DTLS v1.2 across the spectrum of
target ACP nodes. target ACP nodes.
* Firmware of lower end, embedded ACP nodes may not support a newer
o Firmware of lower end, embedded ACP nodes may not support a newer
version for a long time. version for a long time.
* There are significant changes of DTLS v1.3, such as a different
o There are significant changes of DTLS v1.3, such as a different
record layer requiring time to gain implementation and deployment record layer requiring time to gain implementation and deployment
experience especially on lower end, code space limited devices. experience especially on lower end, code space limited devices.
* The existing BCP [RFC7525] for DTLS v1.2 may equally take longer
o The existing BCP [RFC7525] for DTLS v1.2 may equally take longer
time to be updated with experience from a newer DTLS version. time to be updated with experience from a newer DTLS version.
* There are no significant use-case relevant benefits of DTLS v1.3
o There are no significant use-case relevant benefits of DTLS v1.3
over DTLS v1.2 in the context of the ACP options for DTLS. For over DTLS v1.2 in the context of the ACP options for DTLS. For
example, signaling performance improvements for session setup in example, signaling performance improvements for session setup in
DTLS v1.3 is not important for the ACP given the long-lived nature DTLS v1.3 is not important for the ACP given the long-lived nature
of ACP secure channel connections and the fact that DTLS of ACP secure channel connections and the fact that DTLS
connections are mostly link-local (short RTT). connections are mostly link-local (short RTT).
Nevertheless, newer versions of DTLS, such as DTLS v1.3 have more Nevertheless, newer versions of DTLS, such as DTLS v1.3 have more
strict security requirements and use of the latest standard protocol strict security requirements and use of the latest standard protocol
version is for IETF security standards in general recommended. version is for IETF security standards in general recommended.
Therefore, ACP implementations are advised to support all the newer Therefore, ACP implementations are advised to support all the newer
skipping to change at page 56, line 34 skipping to change at page 58, line 4
[RFC-editor: if by the time of AUTH48, DTLS 1.3 would have evolved to [RFC-editor: if by the time of AUTH48, DTLS 1.3 would have evolved to
be an RFC, then not only would the references to the DTLS v1.3 draft be an RFC, then not only would the references to the DTLS v1.3 draft
be changed to the RFC number, but that RFC is then going to be put be changed to the RFC number, but that RFC is then going to be put
into the normative list of references and the above paragraph is into the normative list of references and the above paragraph is
going to be amended to say: Implementations SHOULD support going to be amended to say: Implementations SHOULD support
[DTLSv1.3-RFC]. This is not done right now, because there is no [DTLSv1.3-RFC]. This is not done right now, because there is no
benefit in potentially waiting in RFC-editor queue for that RFC given benefit in potentially waiting in RFC-editor queue for that RFC given
how the text alreayd lays out a non-nrmative desire to support how the text alreayd lays out a non-nrmative desire to support
DTLSv1.3.] DTLSv1.3.]
There is no additional session setup or other security association There is no additional session setup or other security association
besides this simple DTLS setup. As soon as the DTLS session is besides this simple DTLS setup. As soon as the DTLS session is
functional, the ACP peers will exchange ACP IPv6 packets as the functional, the ACP peers will exchange ACP IPv6 packets as the
payload of the DTLS transport connection. Any DTLS defined security payload of the DTLS transport connection. Any DTLS defined security
association mechanisms such as re-keying are used as they would be association mechanisms such as re-keying are used as they would be
for any transport application relying solely on DTLS. for any transport application relying solely on DTLS.
6.7.5. ACP Secure Channel Profiles 6.8.5. ACP Secure Channel Profiles
As explained in the beginning of Section 6.5, there is no single As explained in the beginning of Section 6.6, there is no single
secure channel mechanism mandated for all ACP nodes. Instead, this secure channel mechanism mandated for all ACP nodes. Instead, this
section defines two ACP profiles (baseline and constrained) for ACP section defines two ACP profiles (baseline and constrained) for ACP
nodes that do introduce such requirements. nodes that do introduce such requirements.
A baseline ACP node MUST support IPsec natively and MAY support IPsec An ACP node supporting the "baseline" profile MUST support IPsec
via GRE. If GRE is supported, it MAY be preferred over native IPec. natively and MAY support IPsec via GRE. An ACP node supporting the
A constrained ACP node that cannot support IPsec MUST support DTLS. "constrained" profile node that cannot support IPsec MUST support
An ACP node connecting an area of constrained ACP nodes with an area DTLS. An ACP node connecting an area of constrained ACP nodes with
of baseline ACP nodes needs to support IPsec and DTLS and supports an area of baseline ACP nodes needs to support IPsec and DTLS and
therefore the baseline and constrained profile. supports therefore the baseline and constrained profile.
Explanation: Not all type of ACP nodes can or need to connect Explanation: Not all type of ACP nodes can or need to connect
directly to each other or are able to support or prefer all possible directly to each other or are able to support or prefer all possible
secure channel mechanisms. For example, code space limited IoT secure channel mechanisms. For example, code space limited IoT
devices may only support DTLS because that code exists already on devices may only support DTLS because that code exists already on
them for end-to-end security, but high-end core routers may not want them for end-to-end security, but high-end core routers may not want
to support DTLS because they can perform IPsec in accelerated to support DTLS because they can perform IPsec in accelerated
hardware but would need to support DTLS in an underpowered CPU hardware but would need to support DTLS in an underpowered CPU
forwarding path shared with critical control plane operations. This forwarding path shared with critical control plane operations. This
is not a deployment issue for a single ACP across these type of nodes is not a deployment issue for a single ACP across these type of nodes
skipping to change at page 57, line 33 skipping to change at page 59, line 5
IPsec natively with tunnel mode provides the shortest encapsulation IPsec natively with tunnel mode provides the shortest encapsulation
overhead. GRE may be preferred by legacy implementations because the overhead. GRE may be preferred by legacy implementations because the
virtual interfaces required by ACP design in conjunction with secure virtual interfaces required by ACP design in conjunction with secure
channels have in the past more often been implemented for GRE than channels have in the past more often been implemented for GRE than
purely for native IPsec. purely for native IPsec.
ACP nodes need to specify in documentation the set of secure ACP ACP nodes need to specify in documentation the set of secure ACP
mechanisms they support and should declare which profile they support mechanisms they support and should declare which profile they support
according to above requirements. according to above requirements.
6.8. GRASP in the ACP 6.9. GRASP in the ACP
6.8.1. GRASP as a core service of the ACP 6.9.1. GRASP as a core service of the ACP
The ACP MUST run an instance of GRASP inside of it. It is a key part The ACP MUST run an instance of GRASP inside of it. It is a key part
of the ACP services. The function in GRASP that makes it fundamental of the ACP services. The function in GRASP that makes it fundamental
as a service of the ACP is the ability to provide ACP wide service as a service of the ACP is the ability to provide ACP wide service
discovery (using objectives in GRASP). discovery (using objectives in GRASP).
ACP provides IP unicast routing via the RPL routing protocol (see ACP provides IP unicast routing via the RPL routing protocol (see
Section 6.11). Section 6.12).
The ACP does not use IP multicast routing nor does it provide generic The ACP does not use IP multicast routing nor does it provide generic
IP multicast services (the handling of GRASP link-local multicast IP multicast services (the handling of GRASP link-local multicast
messages is explained in Section 6.8.2). Instead, the ACP provides messages is explained in Section 6.9.2). Instead, the ACP provides
service discovery via the objective discovery/announcement and service discovery via the objective discovery/announcement and
negotiation mechanisms of the ACP GRASP instance (services are a form negotiation mechanisms of the ACP GRASP instance (services are a form
of objectives). These mechanisms use hop-by-hop reliable flooding of of objectives). These mechanisms use hop-by-hop reliable flooding of
GRASP messages for both service discovery (GRASP M_DISCOVERY GRASP messages for both service discovery (GRASP M_DISCOVERY
messages) and service announcement (GRASP M_FLOOD messages). messages) and service announcement (GRASP M_FLOOD messages).
See Appendix A.5 for discussion about this design choice of the ACP. See Appendix A.5 for discussion about this design choice of the ACP.
6.8.2. ACP as the Security and Transport substrate for GRASP 6.9.2. ACP as the Security and Transport substrate for GRASP
In the terminology of GRASP ([I-D.ietf-anima-grasp]), the ACP is the In the terminology of GRASP ([I-D.ietf-anima-grasp]), the ACP is the
security and transport substrate for the GRASP instance run inside security and transport substrate for the GRASP instance run inside
the ACP ("ACP GRASP"). the ACP ("ACP GRASP").
This means that the ACP is responsible for ensuring that this This means that the ACP is responsible for ensuring that this
instance of GRASP is only sending messages across the ACP GRASP instance of GRASP is only sending messages across the ACP GRASP
virtual interfaces. Whenever the ACP adds or deletes such an virtual interfaces. Whenever the ACP adds or deletes such an
interface because of new ACP secure channels or loss thereof, the ACP interface because of new ACP secure channels or loss thereof, the ACP
needs to indicate this to the ACP instance of GRASP. The ACP exists needs to indicate this to the ACP instance of GRASP. The ACP exists
skipping to change at page 58, line 32 skipping to change at page 59, line 51
of its neighbors cease operation. of its neighbors cease operation.
In this case ASAs using GRASP running on the same node would still In this case ASAs using GRASP running on the same node would still
need to be able to discover each other's objectives. When the ACP need to be able to discover each other's objectives. When the ACP
does not exist, ASAs leveraging the ACP instance of GRASP via APIs does not exist, ASAs leveraging the ACP instance of GRASP via APIs
MUST still be able to operate, and MUST be able to understand that MUST still be able to operate, and MUST be able to understand that
there is no ACP and that therefore the ACP instance of GRASP cannot there is no ACP and that therefore the ACP instance of GRASP cannot
operate. operate.
The following explanation how ACP acts as the security and transport The following explanation how ACP acts as the security and transport
substrate for GRASP is visualized in Figure 8 below. substrate for GRASP is visualized in Figure 9 below.
GRASP unicast messages inside the ACP always use the ACP address. GRASP unicast messages inside the ACP always use the ACP address.
Link-local addresses from the ACP VRF MUST NOT be used inside Link-local addresses from the ACP VRF MUST NOT be used inside
objectives. GRASP unicast messages inside the ACP are transported objectives. GRASP unicast messages inside the ACP are transported
via TLS which MUST comply with [RFC7525] execept that only TLS 1.2 via TLS. See Section 6.1 for TLS requirements. TLS mutual
([RFC5246]) is REQUIRED and TLS 1.3 ([RFC8446] is RECOMMENDED. There authentication MUST use the ACP domain membership check defined in
is no need for older version backward compatibility in the new use- (Section 6.2.3).
case of ACP. Mutual authentication MUST use the ACP domain
membership check defined in (Section 6.1.3).
GRASP link-local multicast messages are targeted for a specific ACP GRASP link-local multicast messages are targeted for a specific ACP
virtual interface (as defined Section 6.12.5) but are sent by the ACP virtual interface (as defined Section 6.13.5) but are sent by the ACP
into an ACP GRASP virtual interface that is constructed from the TCP into an ACP GRASP virtual interface that is constructed from the TCP
connection(s) to the IPv6 link-local neighbor address(es) on the connection(s) to the IPv6 link-local neighbor address(es) on the
underlying ACP virtual interface. If the ACP GRASP virtual interface underlying ACP virtual interface. If the ACP GRASP virtual interface
has two or more neighbors, the GRASP link-local multicast messages has two or more neighbors, the GRASP link-local multicast messages
are replicated to all neighbor TCP connections. are replicated to all neighbor TCP connections.
TLS for GRASP MUST offer TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 and
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 and MUST NOT offer options
with less than 256 bit symmetric key strength or hash strength of
less han SHA384. TLS for GRASP MUST also include the "Supported
Elliptic Curves" extension, it MUST support support the NIST P-256
(secp256r1) and P-384 (secp384r1(24)) curves [RFC4492]. In addition,
GRASP TLS clients SHOULD send an ec_point_formats extension with a
single element, "uncompressed". For further interoperability
recommendations, GRASP TLS implementations SHOULD follow [RFC7525].
TCP and TLS connections for GRASP in the ACP use the IANA assigned TCP and TLS connections for GRASP in the ACP use the IANA assigned
TCP port for GRASP (7107). Effectively the transport stack is TCP port for GRASP (7107). Effectively the transport stack is
expected to be TLS for connections from/to the ACP address (e.g., expected to be TLS for connections from/to the ACP address (e.g.,
global scope address(es)) and TCP for connections from/to link-local global scope address(es)) and TCP for connections from/to link-local
addresses on the ACP virtual interfaces. The latter ones are only addresses on the ACP virtual interfaces. The latter ones are only
used for flooding of GRASP messages. used for flooding of GRASP messages.
..............................ACP.............................. ..............................ACP..............................
. . . .
. /-GRASP-flooding-\ ACP GRASP instance . . /-GRASP-flooding-\ ACP GRASP instance .
skipping to change at page 60, line 52 skipping to change at page 61, line 52
. IPsec/DTLS IPsec/DTLS - ACP-cert auth . . IPsec/DTLS IPsec/DTLS - ACP-cert auth .
............................................................... ...............................................................
| | Data-Plane | | Data-Plane
| | | |
| | - ACP secure channel | | - ACP secure channel
link-local link-local - encapsulation addresses link-local link-local - encapsulation addresses
subnet1 subnet2 - Data-Plane interfaces subnet1 subnet2 - Data-Plane interfaces
| | | |
ACP-Nbr1 ACP-Nbr2 ACP-Nbr1 ACP-Nbr2
Figure 8: ACP as security and transport substrate for GRASP Figure 9: ACP as security and transport substrate for GRASP
6.8.2.1. Discussion 6.9.2.1. Discussion
TCP encapsulation for GRASP M_DISCOVERY and M_FLOOD link local TCP encapsulation for GRASP M_DISCOVERY and M_FLOOD link local
messages is used because these messages are flooded across messages is used because these messages are flooded across
potentially many hops to all ACP nodes and a single link with even potentially many hops to all ACP nodes and a single link with even
temporary packet loss issues (e.g., WiFi/Powerline link) can reduce temporary packet loss issues (e.g., WiFi/Powerline link) can reduce
the probability for loss free transmission so much that applications the probability for loss free transmission so much that applications
would want to increase the frequency with which they send these would want to increase the frequency with which they send these
messages. Such shorter periodic retransmission of datagrams would messages. Such shorter periodic retransmission of datagrams would
result in more traffic and processing overhead in the ACP than the result in more traffic and processing overhead in the ACP than the
hop-by-hop reliable retransmission mechanism by TCP and duplicate hop-by-hop reliable retransmission mechanism by TCP and duplicate
elimination by GRASP. elimination by GRASP.
TLS is mandated for GRASP non-link-local unicast because the ACP TLS is mandated for GRASP non-link-local unicast because the ACP
secure channel mandatory authentication and encryption protects only secure channel mandatory authentication and encryption protects only
against attacks from the outside but not against attacks from the against attacks from the outside but not against attacks from the
inside: Compromised ACP members that have (not yet) been detected and inside: Compromised ACP members that have (not yet) been detected and
removed (e.g., via domain certificate revocation / expiry). removed (e.g., via domain certificate revocation / expiry).
If GRASP peer connections were to use just TCP, compromised ACP If GRASP peer connections were to use just TCP, compromised ACP
members could simply eavesdrop passively on GRASP peer connections members could simply eavesdrop passively on GRASP peer connections
for whom they are on-path ("Man In The Middle" - MITM) or intercept for whom they are on-path ("man in the middle" - MITM) or intercept
and modify them. With TLS, it is not possible to completely and modify them. With TLS, it is not possible to completely
eliminate problems with compromised ACP members, but attacks are a eliminate problems with compromised ACP members, but attacks are a
lot more complex: lot more complex:
Eavesdropping/spoofing by a compromised ACP node is still possible Eavesdropping/spoofing by a compromised ACP node is still possible
because in the model of the ACP and GRASP, the provider and consumer because in the model of the ACP and GRASP, the provider and consumer
of an objective have initially no unique information (such as an of an objective have initially no unique information (such as an
identity) about the other side which would allow them to distinguish identity) about the other side which would allow them to distinguish
a benevolent from a compromised peer. The compromised ACP node would a benevolent from a compromised peer. The compromised ACP node would
simply announce the objective as well, potentially filter the simply announce the objective as well, potentially filter the
skipping to change at page 61, line 48 skipping to change at page 62, line 48
application level proxy. This of course requires that the application level proxy. This of course requires that the
compromised ACP node understand the semantics of the GRASP compromised ACP node understand the semantics of the GRASP
negotiation to an extent that allows it to proxy it without being negotiation to an extent that allows it to proxy it without being
detected, but in an ACP environment this is quite likely public detected, but in an ACP environment this is quite likely public
knowledge or even standardized. knowledge or even standardized.
The GRASP TLS connections are run the same as any other ACP traffic The GRASP TLS connections are run the same as any other ACP traffic
through the ACP secure channels. This leads to double through the ACP secure channels. This leads to double
authentication/encryption, which has the following benefits: authentication/encryption, which has the following benefits:
o Secure channel methods such as IPsec may provide protection * Secure channel methods such as IPsec may provide protection
against additional attacks, for example reset-attacks. against additional attacks, for example reset-attacks.
* The secure channel method may leverage hardware acceleration and
o The secure channel method may leverage hardware acceleration and
there may be little or no gain in eliminating it. there may be little or no gain in eliminating it.
o There is no different security model for ACP GRASP from other ACP * There is no different security model for ACP GRASP from other ACP
traffic. Instead, there is just another layer of protection traffic. Instead, there is just another layer of protection
against certain attacks from the inside which is important due to against certain attacks from the inside which is important due to
the role of GRASP in the ACP. the role of GRASP in the ACP.
6.9. Context Separation 6.10. Context Separation
The ACP is in a separate context from the normal Data-Plane of the The ACP is in a separate context from the normal Data-Plane of the
node. This context includes the ACP channels' IPv6 forwarding and node. This context includes the ACP channels' IPv6 forwarding and
routing as well as any required higher layer ACP functions. routing as well as any required higher layer ACP functions.
In classical network system, a dedicated VRF is one logical In classical network system, a dedicated VRF is one logical
implementation option for the ACP. If possible by the systems implementation option for the ACP. If possible by the systems
software architecture, separation options that minimize shared software architecture, separation options that minimize shared
components are preferred, such as a logical container or virtual components are preferred, such as a logical container or virtual
machine instance. The context for the ACP needs to be established machine instance. The context for the ACP needs to be established
automatically during bootstrap of a node. As much as possible it automatically during bootstrap of a node. As much as possible it
should be protected from being modified unintentionally by ("Data- should be protected from being modified unintentionally by ("Data-
Plane") configuration. Plane") configuration.
Context separation improves security, because the ACP is not Context separation improves security, because the ACP is not
reachable from the Data-Plane routing or forwarding table(s). Also, reachable from the Data-Plane routing or forwarding table(s). Also,
configuration errors from the Data-Plane setup do not affect the ACP. configuration errors from the Data-Plane setup do not affect the ACP.
6.10. Addressing inside the ACP 6.11. Addressing inside the ACP
The channels explained above typically only establish communication The channels explained above typically only establish communication
between two adjacent nodes. In order for communication to happen between two adjacent nodes. In order for communication to happen
across multiple hops, the autonomic control plane requires ACP across multiple hops, the autonomic control plane requires ACP
network wide valid addresses and routing. Each ACP node creates a network wide valid addresses and routing. Each ACP node creates a
Loopback interface with an ACP network wide unique address (prefix) Loopback interface with an ACP network wide unique address (prefix)
inside the ACP context (as explained in in Section 6.9). This inside the ACP context (as explained in in Section 6.10). This
address may be used also in other virtual contexts. address may be used also in other virtual contexts.
With the algorithm introduced here, all ACP nodes in the same routing With the algorithm introduced here, all ACP nodes in the same routing
subdomain have the same /48 ULA prefix. Conversely, ULA global IDs subdomain have the same /48 ULA prefix. Conversely, ULA global IDs
from different domains are unlikely to clash, such that two ACP from different domains are unlikely to clash, such that two ACP
networks can be merged, as long as the policy allows that merge. See networks can be merged, as long as the policy allows that merge. See
also Section 10.1 for a discussion on merging domains. also Section 10.1 for a discussion on merging domains.
Links inside the ACP only use link-local IPv6 addressing, such that Links inside the ACP only use link-local IPv6 addressing, such that
each node's ACP only requires one routable address prefix. each node's ACP only requires one routable address prefix.
6.10.1. Fundamental Concepts of Autonomic Addressing 6.11.1. Fundamental Concepts of Autonomic Addressing
o Usage: Autonomic addresses are exclusively used for self- * Usage: Autonomic addresses are exclusively used for self-
management functions inside a trusted domain. They are not used management functions inside a trusted domain. They are not used
for user traffic. Communications with entities outside the for user traffic. Communications with entities outside the
trusted domain use another address space, for example normally trusted domain use another address space, for example normally
managed routable address space (called "Data-Plane" in this managed routable address space (called "Data-Plane" in this
document). document).
* Separation: Autonomic address space is used separately from user
o Separation: Autonomic address space is used separately from user
address space and other address realms. This supports the address space and other address realms. This supports the
robustness requirement. robustness requirement.
* Loopback-only: Only ACP Loopback interfaces (and potentially those
o Loopback-only: Only ACP Loopback interfaces (and potentially those
configured for "ACP connect", see Section 8.1) carry routable configured for "ACP connect", see Section 8.1) carry routable
address(es); all other interfaces (called ACP virtual interfaces) address(es); all other interfaces (called ACP virtual interfaces)
only use IPv6 link local addresses. The usage of IPv6 link local only use IPv6 link local addresses. The usage of IPv6 link local
addressing is discussed in [RFC7404]. addressing is discussed in [RFC7404].
* Use-ULA: For Loopback interfaces of ACP nodes, we use ULA with L=1
o Use-ULA: For Loopback interfaces of ACP nodes, we use ULA with L=1
(as defined in section 3.1 of [RFC4193]). Note that the random (as defined in section 3.1 of [RFC4193]). Note that the random
hash for ACP Loopback addresses uses the definition in hash for ACP Loopback addresses uses the definition in
Section 6.10.2 and not the one of [RFC4193] section 3.2.2. Section 6.11.2 and not the one of [RFC4193] section 3.2.2.
* No external connectivity: They do not provide access to the
o No external connectivity: They do not provide access to the
Internet. If a node requires further reaching connectivity, it Internet. If a node requires further reaching connectivity, it
should use another, traditionally managed address scheme in should use another, traditionally managed address scheme in
parallel. parallel.
* Addresses in the ACP are permanent, and do not support temporary
o Addresses in the ACP are permanent, and do not support temporary
addresses as defined in [RFC4941]. addresses as defined in [RFC4941].
* Addresses in the ACP are not considered sensitive on privacy
o Addresses in the ACP are not considered sensitive on privacy grounds because ACP nodes are not expected to be end-user hosts
grounds because ACP nodes are not expected to be end-user host. and ACP addresses do therefore not represent end-users or groups
All ACP nodes are in one (potentially federated) administrative of end-users. All ACP nodes are in one (potentially federated)
domain. They are assumed to be to be candidate hosts of ACP administrative domain. They are assumed to be to be candidate
traffic amongst each other or transit thereof. There are no hosts of ACP traffic amongst each other or transit thereof. There
transit nodes less privileged to know about the identity of other are no transit nodes less privileged to know about the identity of
hosts in the ACP. Therefore, ACP addresses do not need to be other hosts in the ACP. Therefore, ACP addresses do not need to
pseudo-random as discussed in [RFC7721]. Because they are not be pseudo-random as discussed in [RFC7721]. Because they are not
propagated to untrusted (non ACP) nodes and stay within a domain propagated to untrusted (non ACP) nodes and stay within a domain
(of trust), we also consider them not to be subject to scanning (of trust), we also consider them not to be subject to scanning
attacks. attacks.
The ACP is based exclusively on IPv6 addressing, for a variety of The ACP is based exclusively on IPv6 addressing, for a variety of
reasons: reasons:
o Simplicity, reliability and scale: If other network layer * Simplicity, reliability and scale: If other network layer
protocols were supported, each would have to have its own set of protocols were supported, each would have to have its own set of
security associations, routing table and process, etc. security associations, routing table and process, etc.
* Autonomic functions do not require IPv4: Autonomic functions and
o Autonomic functions do not require IPv4: Autonomic functions and
autonomic service agents are new concepts. They can be autonomic service agents are new concepts. They can be
exclusively built on IPv6 from day one. There is no need for exclusively built on IPv6 from day one. There is no need for
backward compatibility. backward compatibility.
* OAM protocols do not require IPv4: The ACP may carry OAM
o OAM protocols do not require IPv4: The ACP may carry OAM protocols. All relevant protocols (SNMP, TFTP, SSH, SCP, RADIUS,
protocols. All relevant protocols (SNMP, TFTP, SSH, SCP, Radius, Diameter, NETCONF ...) are available in IPv6. See also [RFC8368]
Diameter, ...) are available in IPv6. See also [RFC8368] for how for how ACP could be made to interoperate with IPv4 only OAM.
ACP could be made to interoperate with IPv4 only OAM.
Further explanation about the addressing and routing related reasons Further explanation about the addressing and routing related reasons
for the choice of the autonomous ACP addressing can be found in for the choice of the autonomous ACP addressing can be found in
Section 6.12.5.1. Section 6.13.5.1.
6.10.2. The ACP Addressing Base Scheme 6.11.2. The ACP Addressing Base Scheme
The Base ULA addressing scheme for ACP nodes has the following The Base ULA addressing scheme for ACP nodes has the following
format: format:
8 40 2 78 8 40 2 78
+--+-------------------------+------+------------------------------+ +--+-------------------------+------+------------------------------+
|fd| hash(routing-subdomain) | Type | (sub-scheme) | |fd| hash(routing-subdomain) | Type | (sub-scheme) |
+--+-------------------------+------+------------------------------+ +--+-------------------------+------+------------------------------+
Figure 9: ACP Addressing Base Scheme Figure 10: ACP Addressing Base Scheme
The first 48-bits follow the ULA scheme, as defined in [RFC4193], to The first 48-bits follow the ULA scheme, as defined in [RFC4193], to
which a type field is added: which a type field is added:
o "fd" identifies a locally defined ULA address. * "fd" identifies a locally defined ULA address.
* The 40-bits ULA "global ID" (term from [RFC4193]) for ACP
o The 40-bits ULA "global ID" (term from [RFC4193]) for ACP
addresses carried in the acp-node-name in the ACP certificates are addresses carried in the acp-node-name in the ACP certificates are
the first 40-bits of the SHA256 hash of the routing subdomain from the first 40-bits of the SHA256 hash of the routing subdomain from
the same acp-node-name. In the example of Section 6.1.2, the the same acp-node-name. In the example of Section 6.2.2, the
routing subdomain is "area51.research.acp.example.com" and the routing subdomain is "area51.research.acp.example.com" and the
40-bits ULA "global ID" 89b714f3db. 40-bits ULA "global ID" 89b714f3db.
* When creating a new routing-subdomain for an existing autonomic
o When creating a new routing-subdomain for an existing autonomic
network, it MUST be ensured, that rsub is selected so the network, it MUST be ensured, that rsub is selected so the
resulting hash of the routing-subdomain does not collide with the resulting hash of the routing-subdomain does not collide with the
hash of any pre-existing routing-subdomains of the autonomic hash of any pre-existing routing-subdomains of the autonomic
network. This ensures that ACP addresses created by registrars network. This ensures that ACP addresses created by registrars
for different routing subdomains do not collide with each others. for different routing subdomains do not collide with each others.
* To allow for extensibility, the fact that the ULA "global ID" is a
o To allow for extensibility, the fact that the ULA "global ID" is a
hash of the routing subdomain SHOULD NOT be assumed by any ACP hash of the routing subdomain SHOULD NOT be assumed by any ACP
node during normal operations. The hash function is only executed node during normal operations. The hash function is only executed
during the creation of the certificate. If BRSKI is used then the during the creation of the certificate. If BRSKI is used then the
BRSKI registrar will create the acp-node-name in response to the BRSKI registrar will create the acp-node-name in response to the
EST Certificate Signing Request (CSR) Attribute Request message by EST Certificate Signing Request (CSR) Attribute Request message by
the pledge. the pledge.
o Establishing connectivity between different ACP (different acp- * Establishing connectivity between different ACP (different acp-
domain-name) is outside the scope of this specification. If it is domain-name) is outside the scope of this specification. If it is
being done through future extensions, then the rsub of all being done through future extensions, then the rsub of all
routing-subdomains across those autonomic networks need to be routing-subdomains across those autonomic networks need to be
selected so the resulting routing-subdomain hashes do not collide. selected so the resulting routing-subdomain hashes do not collide.
For example a large cooperation with its own private TA may want For example a large cooperation with its own private TA may want
to create different autonomic networks that initially should not to create different autonomic networks that initially should not
be able to connect but where the option to do so should be kept be able to connect but where the option to do so should be kept
open. When taking this future possibility into account, it is open. When taking this future possibility into account, it is
easy to always select rsub so that no collisions happen. easy to always select rsub so that no collisions happen.
* Type: This field allows different address sub-schemes. This
o Type: This field allows different address sub-schemes. This
addresses the "upgradability" requirement. Assignment of types addresses the "upgradability" requirement. Assignment of types
for this field will be maintained by IANA. for this field will be maintained by IANA.
The sub-scheme may imply a range or set of addresses assigned to the The sub-scheme may imply a range or set of addresses assigned to the
node, this is called the ACP address range/set and explained in each node, this is called the ACP address range/set and explained in each
sub-scheme. sub-scheme.
Please refer to Section 6.10.7 and Appendix A.1 for further Please refer to Section 6.11.7 and Appendix A.1 for further
explanations why the following Sub-Addressing schemes are used and explanations why the following Sub-Addressing schemes are used and
why multiple are necessary. why multiple are necessary.
The following summarizes the addressing Sub-Schemes: The following summarizes the addressing Sub-Schemes:
+------+-----+-----------------+-------+------------+ +------+-----------------+-----------+-------------------+
| Type | Z | name | F-bit | V-bit size | | Type | Name |F-bit| Z | V-bits | Prefix |
+------+-----+-----------------+-------+------------+ +------+-----------------+-----+-----+----------+--------+
| 0x00 | 0 | ACP-Zone | N/A | 1 bit | | 0x00 | ACP-Zone | N/A | 0 | 1 bit | /127 |
+------+-----+-----------------+-------+------------+ +------+-----------------+-----+-----+----------+--------+
| 0x00 | 1 | ACP-Manual | N/A | 1 bit | | 0x00 | ACP-Manual | N/A | 1 | N/A | /64 |
+------+-----+-----------------+-------+------------+ +------+-----------------+-----+-----+----------+--------+
| 0x01 | N/A | ACP-VLong-8 | 0 | 8 bits | | 0x01 | ACP-VLong-8 | 0 | N/A | 8 bits | /120 |
+------+-----+-----------------+-------+------------+ +------+-----------------+-----+-----+----------+--------+
| 0x01 | N/A | ACP-VLong-16 | 1 | 16 bits | | 0x01 | ACP-VLong-16 | 1 | N/A | 16 bits | /112 |
+------+-----+-----------------+-------+------------+ +------+-----------------+-----+-----+----------+--------+
| 0x10 | Reserved / For future definition/allocation |
+------+-----------------+-----+-----+----------+--------+
| 0x11 | Reserved / For future definition/allocation |
+------+-----------------+-----+-----+----------+--------+
Figure 10: Addressing schemes Figure 11: Addressing Sub-Schemes
6.10.3. ACP Zone Addressing Sub-Scheme (ACP-Zone) F-Bit and Z are two encoding fields explained below for the Sub-
Schemes that introduce/use them. V-bits is the number of bits of
addresses allocated to the ACP node. Prefix is the prefix the ACP
node is announcing into the RPL routing protocol.
6.11.3. ACP Zone Addressing Sub-Scheme (ACP-Zone)
This sub-scheme is used when the Type field of the base scheme is This sub-scheme is used when the Type field of the base scheme is
0x00 and the Z bit is 0x0. 0x00 and the Z bit is 0x0.
64 64 64 64
+-----------------+---+---------++-----------------------------+---+ +-----------------+---+---------++-----------------------------+---+
| (base scheme) | Z | Zone-ID || Node-ID | | (base scheme) | Z | Zone-ID || Node-ID |
| | | || Registrar-ID | Node-Number| V | | | | || Registrar-ID | Node-Number| V |
+-----------------+---+---------++--------------+--------------+---+ +-----------------+---+---------++--------------+--------------+---+
50 1 13 48 15 1 50 1 13 48 15 1
Figure 11: ACP Zone Addressing Sub-Scheme Figure 12: ACP Zone Addressing Sub-Scheme
The fields are defined as follows: The fields are defined as follows:
o Type: MUST be 0x0. * Type: MUST be 0x0.
* Z: MUST be 0x0.
o Z: MUST be 0x0. * Zone-ID: A value for a network zone.
* Node-ID: A unique value for each node.
o Zone-ID: A value for a network zone.
o Node-ID: A unique value for each node.
The 64-bit Node-ID must be unique across the ACP domain for each The 64-bit Node-ID must be unique across the ACP domain for each
node. It is derived and composed as follows: node. It is derived and composed as follows:
o Registrar-ID (48-bit): A number unique inside the domain that * Registrar-ID (48-bit): A number unique inside the domain that
identifies the ACP registrar which assigned the Node-ID to the identifies the ACP registrar which assigned the Node-ID to the
node. One or more domain-wide unique identifiers of the ACP node. One or more domain-wide unique identifiers of the ACP
registrar can be used for this purpose. See Section 6.10.7.2. registrar can be used for this purpose. See Section 6.11.7.2.
* Node-Number: Number to make the Node-ID unique. This can be
o Node-Number: Number to make the Node-ID unique. This can be
sequentially assigned by the ACP Registrar owning the Registrar- sequentially assigned by the ACP Registrar owning the Registrar-
ID. ID.
* V (1-bit): Virtualization bit: 0: Indicates the ACP itself ("ACP
o V (1-bit): Virtualization bit: 0: Indicates the ACP itself ("ACP
node base system); 1: Indicates the optional "host" context on the node base system); 1: Indicates the optional "host" context on the
ACP node (see below). ACP node (see below).
In the ACP Zone Addressing Sub-Scheme, the ACP address in the In the ACP Zone Addressing Sub-Scheme, the ACP address in the
certificate has V field as all zero bits. certificate has V field as all zero bits.
The ACP address set of the node includes addresses with any Zone-ID The ACP address set of the node includes addresses with any Zone-ID
value and any V value. No two nodes in the same ACP can have the value and any V value. No two nodes in the same ACP can have the
same Node-ID, but differerent Zone-IDs. same Node-ID, but differerent Zone-IDs.
skipping to change at page 67, line 26 skipping to change at page 68, line 26
be used in conjunction with operational practices for partial/ be used in conjunction with operational practices for partial/
incremental adoption of the ACP as described in Section 9.4. incremental adoption of the ACP as described in Section 9.4.
Note: Zones and Zone-ID as defined here are not related to [RFC4007] Note: Zones and Zone-ID as defined here are not related to [RFC4007]
zones or zone_id. ACP zone addresses are not scoped (reachable only zones or zone_id. ACP zone addresses are not scoped (reachable only
from within an RFC4007 zone) but reachable across the whole ACP. An from within an RFC4007 zone) but reachable across the whole ACP. An
RFC4007 zone_id is a zone index that has only local significance on a RFC4007 zone_id is a zone index that has only local significance on a
node, whereas an ACP Zone-ID is an identifier for an ACP zone that is node, whereas an ACP Zone-ID is an identifier for an ACP zone that is
unique across that ACP. unique across that ACP.
6.10.4. ACP Manual Addressing Sub-Scheme (ACP-Manual) 6.11.4. ACP Manual Addressing Sub-Scheme (ACP-Manual)
This sub-scheme is used when the Type field of the base scheme is This sub-scheme is used when the Type field of the base scheme is
0x00 and the Z bit is 0x1. 0x00 and the Z bit is 0x1.
64 64 64 64
+---------------------+---+----------++-----------------------------+ +---------------------+---+----------++-----------------------------+
| (base scheme) | Z | Subnet-ID|| Interface Identifier | | (base scheme) | Z | Subnet-ID|| Interface Identifier |
+---------------------+---+----------++-----------------------------+ +---------------------+---+----------++-----------------------------+
50 1 13 50 1 13
Figure 12: ACP Manual Addressing Sub-Scheme Figure 13: ACP Manual Addressing Sub-Scheme
The fields are defined as follows: The fields are defined as follows:
o Type: MUST be 0x0. * Type: MUST be 0x0.
* Z: MUST be 0x1.
o Z: MUST be 0x1. * Subnet-ID: Configured subnet identifier.
* Interface Identifier.
o Subnet-ID: Configured subnet identifier.
o Interface Identifier.
This sub-scheme is meant for "manual" allocation to subnets where the This sub-scheme is meant for "manual" allocation to subnets where the
other addressing schemes cannot be used. The primary use case is for other addressing schemes cannot be used. The primary use case is for
assignment to ACP connect subnets (see Section 8.1.1). assignment to ACP connect subnets (see Section 8.1.1).
"Manual" means that allocations of the Subnet-ID need to be done "Manual" means that allocations of the Subnet-ID need to be done
today with pre-existing, non-autonomic mechanisms. Every subnet that today with pre-existing, non-autonomic mechanisms. Every subnet that
uses this addressing sub-scheme needs to use a unique Subnet-ID uses this addressing sub-scheme needs to use a unique Subnet-ID
(unless some anycast setup is done). (unless some anycast setup is done).
skipping to change at page 68, line 26 skipping to change at page 69, line 22
scheme and therefore allowing for the Vlong scheme (described below) scheme and therefore allowing for the Vlong scheme (described below)
to have one more bit available. to have one more bit available.
Manual addressing sub-scheme addresses SHOULD NOT be used in ACP Manual addressing sub-scheme addresses SHOULD NOT be used in ACP
certificates. Any node capable to build ACP secure channels and certificates. Any node capable to build ACP secure channels and
permitted by Registrar policy to participate in building ACP secure permitted by Registrar policy to participate in building ACP secure
channels SHOULD receive an ACP address (prefix) from one of the other channels SHOULD receive an ACP address (prefix) from one of the other
ACP addressing sub-schemes. Nodes not capable (or permitted) to ACP addressing sub-schemes. Nodes not capable (or permitted) to
participate in ACP secure channels can connect to the ACP via ACP participate in ACP secure channels can connect to the ACP via ACP
connect interfaces of ACP edge nodes (see Section 8.1), without connect interfaces of ACP edge nodes (see Section 8.1), without
setting up an ACP secure channel. Their ACP certificate MUST include setting up an ACP secure channel. Their ACP certificate MUST omit
an empty acp-address to indicate that their ACP certificate is only the acp-address field to indicate that their ACP certificate is only
usable for non- ACP secure channel authentication, such as end-to-end usable for non- ACP secure channel authentication, such as end-to-end
transport connections across the ACP or Data-Plane. transport connections across the ACP or Data-Plane.
Address management of ACP connect subnets is done using traditional Address management of ACP connect subnets is done using traditional
assignment methods and existing IPv6 protocols. See Section 8.1.3 assignment methods and existing IPv6 protocols. See Section 8.1.3
for details. for details. Therefore the notion of V-bit many addresses assigned
to the ACP nodes does not apply to this Sub-Scheme.
6.10.5. ACP Vlong Addressing Sub-Scheme (ACP-VLong-8/ACP-VLong-16 6.11.5. ACP Vlong Addressing Sub-Scheme (ACP-VLong-8/ACP-VLong-16
This sub-scheme is used when the Type field of the base scheme is This sub-scheme is used when the Type field of the base scheme is
0x01. 0x01.
50 78 50 78
+---------------------++-----------------------------+----------+ +---------------------++-----------------------------+----------+
| (base scheme) || Node-ID | | (base scheme) || Node-ID |
| || Registrar-ID |F| Node-Number| V | | || Registrar-ID |F| Node-Number| V |
+---------------------++--------------+--------------+----------+ +---------------------++--------------+--------------+----------+
50 46 1 23/15 8/16 50 46 1 23/15 8/16
Figure 13: ACP Vlong Addressing Sub-Scheme Figure 14: ACP Vlong Addressing Sub-Scheme
This addressing scheme foregoes the Zone-ID field to allow for This addressing scheme foregoes the Zone-ID field to allow for
larger, flatter routed networks (e.g., as in IoT) with 8421376 Node- larger, flatter routed networks (e.g., as in IoT) with 8421376 Node-
Numbers (2^23+2^15). It also allows for up to 2^16 (i.e. 65536) Numbers (2^23+2^15). It also allows for up to 2^16 (i.e. 65536)
different virtualized addresses within a node, which could be used to different virtualized addresses within a node, which could be used to
address individual software components in an ACP node. address individual software components in an ACP node.
The fields are the same as in the Zone-ID sub-scheme with the The fields are the same as in the Zone-ID sub-scheme with the
following refinements: following refinements:
o F: format bit. This bit determines the format of the subsequent * F: format bit. This bit determines the format of the subsequent
bits. bits.
* V: Virtualization bit: this is a field that is either 8 or 16
o V: Virtualization bit: this is a field that is either 8 or 16
bits. For F=0, it is 8 bits, for F=1 it is 16 bits. The V bits bits. For F=0, it is 8 bits, for F=1 it is 16 bits. The V bits
are assigned by the ACP node. In the ACP certificate's ACP are assigned by the ACP node. In the ACP certificate's ACP
address Section 6.1.2, the V-bits are always set to 0. address Section 6.2.2, the V-bits are always set to 0.
* Registrar-ID: To maximize Node-Number and V, the Registrar-ID is
o Registrar-ID: To maximize Node-Number and V, the Registrar-ID is
reduced to 46-bits. One or more domain-wide unique identifiers of reduced to 46-bits. One or more domain-wide unique identifiers of
the ACP registrar can be used for this purpose. See the ACP registrar can be used for this purpose. See
Section 6.10.7.2. Section 6.11.7.2.
* The Node-Number is unique to each ACP node. There are two formats
o The Node-Number is unique to each ACP node. There are two formats
for the Node-Number. When F=0, the node-number is 23 bits, for for the Node-Number. When F=0, the node-number is 23 bits, for
F=1 it is 15 bits. Each format of node-number is considered to be F=1 it is 15 bits. Each format of node-number is considered to be
in a unique number space. in a unique number space.
The F=0 bit format addresses are intended to be used for "general The F=0 bit format addresses are intended to be used for "general
purpose" ACP nodes that would potentially have a limited number (< purpose" ACP nodes that would potentially have a limited number (<
256) of clients (ASA/Autonomic Functions or legacy services) of the 256) of clients (ASA/Autonomic Functions or legacy services) of the
ACP that require separate V(irtual) addresses. ACP that require separate V(irtual) addresses.
The F=1 bit Node-Numbers are intended for ACP nodes that are ACP edge The F=1 bit Node-Numbers are intended for ACP nodes that are ACP edge
nodes (see Section 8.1.1) or that have a large number of clients nodes (see Section 8.1.1) or that have a large number of clients
requiring separate V(irtual) addresses. For example large SDN requiring separate V(irtual) addresses. For example large SDN
controllers with container modular software architecture (see controllers with container modular software architecture (see
Section 8.1.2). Section 8.1.2).
In the Vlong addressing sub-scheme, the ACP address in the In the Vlong addressing sub-scheme, the ACP address in the
certificate has all V field bits as zero. The ACP address set for certificate has all V field bits as zero. The ACP address set for
the node includes any V value. the node includes any V value.
6.10.6. Other ACP Addressing Sub-Schemes 6.11.6. Other ACP Addressing Sub-Schemes
Before further addressing sub-schemes are defined, experience with Before further addressing sub-schemes are defined, experience with
the schemes defined here should be collected. The schemes defined in the schemes defined here should be collected. The schemes defined in
this document have been devised to allow hopefully sufficiently this document have been devised to allow hopefully sufficiently
flexible setup of ACPs for a variety of situation. These reasons flexible setup of ACPs for a variety of situation. These reasons
also lead to the fairly liberal use of address space: The Zone also lead to the fairly liberal use of address space: The Zone
Addressing Sub-Scheme is intended to enable optimized routing in Addressing Sub-Scheme is intended to enable optimized routing in
large networks by reserving bits for Zone-ID's. The Vlong addressing large networks by reserving bits for Zone-ID's. The Vlong addressing
sub-scheme enables the allocation of 8/16-bit of addresses inside sub-scheme enables the allocation of 8/16-bit of addresses inside
individual ACP nodes. Both address spaces allow distributed, individual ACP nodes. Both address spaces allow distributed,
uncoordinated allocation of node addresses by reserving bits for the uncoordinated allocation of node addresses by reserving bits for the
registrar-ID field in the address. registrar-ID field in the address.
IANA is asked need to assign a new "type" for each new addressing 6.11.7. ACP Registrars
sub-scheme. With the current allocations, only 2 more schemes are
possible, so the last addressing scheme MUST provide further
extensions (e.g., by reserving bits from it for further extensions).
6.10.7. ACP Registrars
ACP registrars are responsible to enroll candidate ACP nodes with ACP ACP registrars are responsible to enroll candidate ACP nodes with ACP
certificates and associated trust anchor(s). They are also certificates and associated trust anchor(s). They are also
responsible that an acp-node-name field is included in the ACP responsible that an acp-node-name field is included in the ACP
certificate carrying the ACP domain name and the ACP nodes ACP certificate carrying the ACP domain name and the ACP nodes ACP
address prefix. This address prefix is intended to persist unchanged address prefix. This address prefix is intended to persist unchanged
through the lifetime of the ACP node. through the lifetime of the ACP node.
Because of the ACP addressing sub-schemes, an ACP domain can have Because of the ACP addressing sub-schemes, an ACP domain can have
multiple distributed ACP registrars that do not need to coordinate multiple distributed ACP registrars that do not need to coordinate
skipping to change at page 70, line 40 skipping to change at page 71, line 31
ACP registrars are PKI registration authorities (RA) enhanced with ACP registrars are PKI registration authorities (RA) enhanced with
the handling of the ACP certificate specific fields. They request the handling of the ACP certificate specific fields. They request
certificates for ACP nodes from a Certification Authority through any certificates for ACP nodes from a Certification Authority through any
appropriate mechanism (out of scope in this document, but required to appropriate mechanism (out of scope in this document, but required to
be BRSKI for ANI registrars). Only nodes that are trusted to be be BRSKI for ANI registrars). Only nodes that are trusted to be
compliant with the requirements against registrar described in this compliant with the requirements against registrar described in this
section can be given the necessary credentials to perform this RA section can be given the necessary credentials to perform this RA
function, such as credentials for the BRSKI connection to the CA for function, such as credentials for the BRSKI connection to the CA for
ANI registrars. ANI registrars.
6.10.7.1. Use of BRSKI or other Mechanism/Protocols 6.11.7.1. Use of BRSKI or other Mechanism/Protocols
Any protocols or mechanisms may be used as ACP registrars, as long as Any protocols or mechanisms may be used by ACP registrars, as long as
the resulting ACP certificate and TA certificate(s) allow to perform the resulting ACP certificate and TA certificate(s) allow to perform
the ACP domain membership described in Section 6.1.3 with other ACP the ACP domain membership described in Section 6.2.3 with other ACP
domain members, and meet the ACP addressing requirements for its acp- domain members, and meet the ACP addressing requirements for its acp-
node-name as described further below in this section. node-name as described further below in this section.
An ACP registrar could be a person deciding whether to enroll a An ACP registrar could be a person deciding whether to enroll a
candidate ACP node and then orchestrating the enrollment of the ACP candidate ACP node and then orchestrating the enrollment of the ACP
certificate and associated TA, using command line or web based certificate and associated TA, using command line or web based
commands on the candidate ACP node and TA to generate and sign the commands on the candidate ACP node and TA to generate and sign the
ACP certificate and configure certificate and TA onto the node. ACP certificate and configure certificate and TA onto the node.
The only currently defined protocol for ACP registrars is BRSKI The only currently defined protocol for ACP registrars is BRSKI
([I-D.ietf-anima-bootstrapping-keyinfra]). When BRSKI is used, the ([I-D.ietf-anima-bootstrapping-keyinfra]). When BRSKI is used, the
ACP nodes are called ANI nodes, and the ACP registrars are called ACP nodes are called ANI nodes, and the ACP registrars are called
BRSKI or ANI registrars. The BRSKI specification does not define the BRSKI or ANI registrars. The BRSKI specification does not define the
handling of the acp-node-name field because the rules do not depend handling of the acp-node-name field because the rules do not depend
on BRSKI but apply equally to any protocols/mechanisms an ACP on BRSKI but apply equally to any protocols/mechanisms an ACP
registrar may use. registrar may use.
6.10.7.2. Unique Address/Prefix allocation 6.11.7.2. Unique Address/Prefix allocation
ACP registrars MUST NOT allocate ACP address prefixes to ACP nodes ACP registrars MUST NOT allocate ACP address prefixes to ACP nodes
via the acp-node-name that would collide with the ACP address via the acp-node-name that would collide with the ACP address
prefixes of other ACP nodes in the same ACP domain. This includes prefixes of other ACP nodes in the same ACP domain. This includes
both prefixes allocated by the same ACP registrar to different ACP both prefixes allocated by the same ACP registrar to different ACP
nodes as well as prefixes allocated by other ACP registrars for the nodes as well as prefixes allocated by other ACP registrars for the
same ACP domain. same ACP domain.
To support such unique address allocation, an ACP registrar MUST have To support such unique address allocation, an ACP registrar MUST have
one or more 46-bit identifiers unique across the ACP domain which is one or more 46-bit identifiers unique across the ACP domain which is
skipping to change at page 71, line 45 skipping to change at page 72, line 35
centrally administered, lightweight ACP registrar implementations. centrally administered, lightweight ACP registrar implementations.
There is no mechanism to deduce from a MAC address itself whether it There is no mechanism to deduce from a MAC address itself whether it
is actually uniquely assigned. Implementations need to consult is actually uniquely assigned. Implementations need to consult
additional offline information before making this assumption. For additional offline information before making this assumption. For
example by knowing that a particular physical product/MIC-chip is example by knowing that a particular physical product/MIC-chip is
guaranteed to use globally unique assigned EUI-48 MAC address(es). guaranteed to use globally unique assigned EUI-48 MAC address(es).
When the candidate ACP device (called Pledge in BRSKI) is to be When the candidate ACP device (called Pledge in BRSKI) is to be
enrolled into an ACP domain, the ACP registrar needs to allocate a enrolled into an ACP domain, the ACP registrar needs to allocate a
unique ACP address to the node and ensure that the ACP certificate unique ACP address to the node and ensure that the ACP certificate
gets a acp-node-name field (Section 6.1.2) with the appropriate gets a acp-node-name field (Section 6.2.2) with the appropriate
information - ACP domain-name, ACP-address, and so on. If the ACP information - ACP domain-name, ACP-address, and so on. If the ACP
registrar uses BRSKI, it signals the ACP acp-node-name field to the registrar uses BRSKI, it signals the ACP acp-node-name field to the
Pledge via the EST /csrattrs command (see Pledge via the EST /csrattrs command (see
[I-D.ietf-anima-bootstrapping-keyinfra], section 5.9.2 - "EST CSR [I-D.ietf-anima-bootstrapping-keyinfra], section 5.9.2 - "EST CSR
Attributes"). Attributes").
[RFC Editor: please update reference to section 5.9.2 accordingly [RFC Editor: please update reference to section 5.9.2 accordingly
with latest BRSKI draft at time of publishing, or RFC] with latest BRSKI draft at time of publishing, or RFC]
6.10.7.3. Addressing Sub-Scheme Policies 6.11.7.3. Addressing Sub-Scheme Policies
The ACP registrar selects for the candidate ACP node a unique address The ACP registrar selects for the candidate ACP node a unique address
prefix from an appropriate ACP addressing sub-scheme, either a zone prefix from an appropriate ACP addressing sub-scheme, either a zone
addressing sub-scheme prefix (see Section 6.10.3), or a Vlong addressing sub-scheme prefix (see Section 6.11.3), or a Vlong
addressing sub-scheme prefix (see Section 6.10.5). The assigned ACP addressing sub-scheme prefix (see Section 6.11.5). The assigned ACP
address prefix encoded in the acp-node-name field of the ACP address prefix encoded in the acp-node-name field of the ACP
certificate indicates to the ACP node its ACP address information. certificate indicates to the ACP node its ACP address information.
The sub-addressing scheme indicates the prefix length: /127 for zone The sub-addressing scheme indicates the prefix length: /127 for zone
address sub-scheme, /120 or /112 for Vlong address sub-scheme. The address sub-scheme, /120 or /112 for Vlong address sub-scheme. The
first address of the prefix is the ACP address. All other addresses first address of the prefix is the ACP address. All other addresses
in the prefix are for other uses by the ACP node as described in the in the prefix are for other uses by the ACP node as described in the
zone and Vlong addressing sub scheme sections. The ACP address zone and Vlong addressing sub scheme sections. The ACP address
prefix itself is then signaled by the ACP node into the ACP routing prefix itself is then signaled by the ACP node into the ACP routing
protocol (see Section 6.11) to establish IPv6 reachability across the protocol (see Section 6.12) to establish IPv6 reachability across the
ACP. ACP.
The choice of addressing sub-scheme and prefix-length in the Vlong The choice of addressing sub-scheme and prefix-length in the Vlong
address sub-scheme is subject to ACP registrar policy. It could be address sub-scheme is subject to ACP registrar policy. It could be
an ACP domain wide policy, or a per ACP node or per ACP node type an ACP domain wide policy, or a per ACP node or per ACP node type
policy. For example, in BRSKI, the ACP registrar is aware of the policy. For example, in BRSKI, the ACP registrar is aware of the
IDevID certificate of the candidate ACP node, which contains a IDevID certificate of the candidate ACP node, which typically
"serialNnumber" that is typically indicating the node's vendor and contains a "serialNumber" attribute in the subjects field
device type and can be used to drive a policy selecting an distinguished name encoding that is often indicating the node's
vendor and device type and can be used to drive a policy selecting an
appropriate addressing sub-scheme for the (class of) node(s). appropriate addressing sub-scheme for the (class of) node(s).
ACP registrars SHOULD default to allocate ACP zone sub-address scheme ACP registrars SHOULD default to allocate ACP zone sub-address scheme
addresses with Zone-ID 0. addresses with Zone-ID 0.
ACP registrars that are aware of the IDevID certificate of a ACP registrars that are aware of the IDevID certificate of a
candidate ACP device SHOULD be able to choose the zone vs. Vlong sub- candidate ACP device SHOULD be able to choose the zone vs. Vlong sub-
address scheme for ACP nodes based on the "serialNumber" of the address scheme for ACP nodes based on the [X.520] "serialNumber"
attribute in the subjects field distinguished name encoding of the
IDevID certificate, for example by the PID (Product Identifier) part IDevID certificate, for example by the PID (Product Identifier) part
which identifies the product type, or the complete "serialNumber". which identifies the product type, or the complete "serialNumber".
The PID for example could identify nodes that allow for specialized The PID for example could identify nodes that allow for specialized
ASA requiring multiple addresses or non-autonomic VMs for services ASA requiring multiple addresses or non-autonomic VMs for services
and those nodes could receive Vlong sub-address scheme ACP addresses. and those nodes could receive Vlong sub-address scheme ACP addresses.
In a simple allocation scheme, an ACP registrar remembers In a simple allocation scheme, an ACP registrar remembers
persistently across reboots its currently used Registrar-ID and for persistently across reboots its currently used Registrar-ID and for
each addressing scheme (Zone with Zone-ID 0, Vlong with /112, Vlong each addressing scheme (Zone with Zone-ID 0, Vlong with /112, Vlong
with /120), the next Node-Number available for allocation and with /120), the next Node-Number available for allocation and
skipping to change at page 73, line 15 skipping to change at page 74, line 15
If allocated addresses can not be remembered by registrars, then it If allocated addresses can not be remembered by registrars, then it
is necessary to either use a new value for the Register-ID field in is necessary to either use a new value for the Register-ID field in
the ACP addresses, or determine allocated ACP addresses from the ACP addresses, or determine allocated ACP addresses from
determining the addresses of reachable ACP nodes, which is not determining the addresses of reachable ACP nodes, which is not
necessarily the set of all ACP nodes. Non-tracked ACP addresses can necessarily the set of all ACP nodes. Non-tracked ACP addresses can
be reclaimed by revoking or not renewing their certificates and be reclaimed by revoking or not renewing their certificates and
instead handing out new certificate with new addresses (for example instead handing out new certificate with new addresses (for example
with a new Registrar-ID value). Note that such strategies may with a new Registrar-ID value). Note that such strategies may
require coordination amongst registrars. require coordination amongst registrars.
6.10.7.4. Address/Prefix Persistence 6.11.7.4. Address/Prefix Persistence
When an ACP certificate is renewed or rekeyed via EST or other When an ACP certificate is renewed or rekeyed via EST or other
mechanisms, the ACP address/prefix in the acp-node-name field MUST be mechanisms, the ACP address/prefix in the acp-node-name field MUST be
maintained unless security issues or violations of the unique address maintained unless security issues or violations of the unique address
assignment requirements exist or are suspected by the ACP registrar. assignment requirements exist or are suspected by the ACP registrar.
ACP address information SHOULD be maintained even when the renewing/ ACP address information SHOULD be maintained even when the renewing/
rekeying ACP registrar is not the same as the one that enrolled the rekeying ACP registrar is not the same as the one that enrolled the
prior ACP certificate. See Section 9.2.4 for an example. prior ACP certificate. See Section 9.2.4 for an example.
ACP address information SHOULD also be maintained even after an ACP ACP address information SHOULD also be maintained even after an ACP
certificate did expire or failed. See Section 6.1.5.5 and certificate did expire or failed. See Section 6.2.5.5 and
Section 6.1.5.6. Section 6.2.5.6.
6.10.7.5. Further Details 6.11.7.5. Further Details
Section 9.2 discusses further informative details of ACP registrars: Section 9.2 discusses further informative details of ACP registrars:
What interactions registrars need, what parameters they require, What interactions registrars need, what parameters they require,
certificate renewal and limitations, use of sub-CAs on registrars and certificate renewal and limitations, use of sub-CAs on registrars and
centralized policy control. centralized policy control.
6.11. Routing in the ACP 6.12. Routing in the ACP
Once ULA address are set up all autonomic entities should run a Once ULA address are set up all autonomic entities should run a
routing protocol within the autonomic control plane context. This routing protocol within the autonomic control plane context. This
routing protocol distributes the ULA created in the previous section routing protocol distributes the ULA created in the previous section
for reachability. The use of the autonomic control plane specific for reachability. The use of the autonomic control plane specific
context eliminates the probable clash with Data-Plane routing tables context eliminates the probable clash with Data-Plane routing tables
and also secures the ACP from interference from the configuration and also secures the ACP from interference from the configuration
mismatch or incorrect routing updates. mismatch or incorrect routing updates.
The establishment of the routing plane and its parameters are The establishment of the routing plane and its parameters are
skipping to change at page 74, line 16 skipping to change at page 75, line 16
channels of the ACP are encrypted, and this routing runs only inside channels of the ACP are encrypted, and this routing runs only inside
the ACP. the ACP.
The routing protocol inside the ACP is RPL ([RFC6550]). See The routing protocol inside the ACP is RPL ([RFC6550]). See
Appendix A.4 for more details on the choice of RPL. Appendix A.4 for more details on the choice of RPL.
RPL adjacencies are set up across all ACP channels in the same domain RPL adjacencies are set up across all ACP channels in the same domain
including all its routing subdomains. See Appendix A.7 for more including all its routing subdomains. See Appendix A.7 for more
details. details.
6.11.1. ACP RPL Profile 6.12.1. ACP RPL Profile
The following is a description of the RPL profile that ACP nodes need The following is a description of the RPL profile that ACP nodes need
to support by default. The format of this section is derived from to support by default. The format of this section is derived from
[I-D.ietf-roll-applicability-template]. [I-D.ietf-roll-applicability-template].
6.11.1.1. Overview 6.12.1.1. Overview
RPL Packet Information (RPI) defined in [RFC6550], section 11.2 RPL Packet Information (RPI) defined in [RFC6550], section 11.2
defines the data packet artefacts required or beneficial in defines the data packet artefacts required or beneficial in
forwarding of packets routed by RPL. This profile does not use RPI forwarding of packets routed by RPL. This profile does not use RPI
for better compatibility with accelerated hardware forwarding planes for better compatibility with accelerated hardware forwarding planes
which most often does not support the Hop-by-Hop headers used for which most often does not support the Hop-by-Hop headers used for
RPI, but also to avoid the overhead of the RPI header on the wire and RPI, but also to avoid the overhead of the RPI header on the wire and
cost of adding/removing them. cost of adding/removing them.
6.11.1.1.1. Single Instance 6.12.1.1.1. Single Instance
To avoid the need for RPI, the ACP RPL profile uses a simple To avoid the need for RPI, the ACP RPL profile uses a simple
destination prefix based routing/forwarding table. To achieve this, destination prefix based routing/forwarding table. To achieve this,
the profiles uses only one RPL instanceID. This single instanceID the profiles uses only one RPL instanceID. This single instanceID
can contain only one Destination Oriented Directed Acyclic Graph can contain only one Destination Oriented Directed Acyclic Graph
(DODAG), and the routing/forwarding table can therefore only (DODAG), and the routing/forwarding table can therefore only
calculate a single class of service ("best effort towards the primary calculate a single class of service ("best effort towards the primary
NOC/root") and cannot create optimized routing paths to accomplish NOC/root") and cannot create optimized routing paths to accomplish
latency or energy goals between any two nodes. latency or energy goals between any two nodes.
skipping to change at page 75, line 17 skipping to change at page 76, line 17
Plane forwarding failures including choosing a different root when Plane forwarding failures including choosing a different root when
the primary one fails. the primary one fails.
The benefit of this profile, especially compared to other IGPs is The benefit of this profile, especially compared to other IGPs is
that it does not calculate routes for node reachable through the same that it does not calculate routes for node reachable through the same
interface as the DODAG root. This RPL profile can therefore scale to interface as the DODAG root. This RPL profile can therefore scale to
much larger number of ACP nodes in the same amount of compute and much larger number of ACP nodes in the same amount of compute and
memory than other routing protocols. Especially on nodes that are memory than other routing protocols. Especially on nodes that are
leafs of the topology or those close to those leafs. leafs of the topology or those close to those leafs.
6.11.1.1.2. Reconvergence 6.12.1.1.2. Reconvergence
In RPL profiles where RPL Packet Information (RPI, see In RPL profiles where RPL Packet Information (RPI, see
Section 6.11.1.13) is present, it is also used to trigger Section 6.12.1.13) is present, it is also used to trigger
reconvergence when misrouted, for example looping, packets are reconvergence when misrouted, for example looping, packets are
recognized because of their RPI data. This helps to minimize RPL recognized because of their RPI data. This helps to minimize RPL
signaling traffic especially in networks without stable topology and signaling traffic especially in networks without stable topology and
slow links. slow links.
The ACP RPL profile instead relies on quick reconverging the DODAG by The ACP RPL profile instead relies on quick reconverging the DODAG by
recognizing link state change (down/up) and triggering reconvergence recognizing link state change (down/up) and triggering reconvergence
signaling as described in Section 6.11.1.7. Since links in the ACP signaling as described in Section 6.12.1.7. Since links in the ACP
are assumed to be mostly reliable (or have link layer protection are assumed to be mostly reliable (or have link layer protection
against loss) and because there is no stretch according to against loss) and because there is no stretch according to
Section 6.11.1.7, loops caused by loss of RPL routing protocol Section 6.12.1.7, loops caused by loss of RPL routing protocol
signaling packets should be exceedingly rare. signaling packets should be exceedingly rare.
In addition, there are a variety of mechanisms possible in RPL to In addition, there are a variety of mechanisms possible in RPL to
further avoid temporary loops RECOMMENDED to be used for the ACPL RPL further avoid temporary loops RECOMMENDED to be used for the ACPL RPL
profile: DODAG Information Objects (DIOs) SHOULD be sent 2 or 3 times profile: DODAG Information Objects (DIOs) SHOULD be sent 2 or 3 times
to inform children when losing the last parent. The technique in to inform children when losing the last parent. The technique in
[RFC6550] section 8.2.2.6. (Detaching) SHOULD be favored over that [RFC6550] section 8.2.2.6. (Detaching) SHOULD be favored over that
in section 8.2.2.5., (Poisoning) because it allows local in section 8.2.2.5., (Poisoning) because it allows local
connectivity. Nodes SHOULD select more than one parent, at least 3 connectivity. Nodes SHOULD select more than one parent, at least 3
if possible, and send Destination Advertisement Objects (DAO)s to all if possible, and send Destination Advertisement Objects (DAO)s to all
of them in parallel. of them in parallel.
Additionally, failed ACP tunnels can be quickly discovered trough the Additionally, failed ACP tunnels can be quickly discovered trough the
secure channel protocol mechanisms such as IKEv2 Dead Peer Detection. secure channel protocol mechanisms such as IKEv2 Dead Peer Detection.
This can function as a replacement for a Low-power and Lossy This can function as a replacement for a Low-power and Lossy
Networks' (LLN's) Expected Transmission Count (ETX) feature that is Networks' (LLN's) Expected Transmission Count (ETX) feature that is
not used in this profile. A failure of an ACP tunnel should not used in this profile. A failure of an ACP tunnel should
imediately signal the RPL control plane to pick a different parent. imediately signal the RPL control plane to pick a different parent.
6.11.1.2. RPL Instances 6.12.1.2. RPL Instances
Single RPL instance. Default RPLInstanceID = 0. Single RPL instance. Default RPLInstanceID = 0.
6.11.1.3. Storing vs. Non-Storing Mode 6.12.1.3. Storing vs. Non-Storing Mode
RPL Mode of Operations (MOP): MUST support mode 2 - "Storing Mode of RPL Mode of Operations (MOP): MUST support mode 2 - "Storing Mode of
Operations with no multicast support". Implementations MAY support Operations with no multicast support". Implementations MAY support
mode 3 ("... with multicast support" as that is a superset of mode mode 3 ("... with multicast support" as that is a superset of mode
2). Note: Root indicates mode in DIO flow. 2). Note: Root indicates mode in DIO flow.
6.11.1.4. DAO Policy 6.12.1.4. DAO Policy
Proactive, aggressive DAO state maintenance: Proactive, aggressive DAO state maintenance:
o Use K-flag in unsolicited DAO indicating change from previous * Use K-flag in unsolicited DAO indicating change from previous
information (to require DAO-ACK). information (to require DAO-ACK).
* Retry such DAO DAO-RETRIES(3) times with DAO- ACK_TIME_OUT(256ms)
o Retry such DAO DAO-RETRIES(3) times with DAO- ACK_TIME_OUT(256ms)
in between. in between.
6.11.1.5. Path Metric 6.12.1.5. Path Metric
Use Hopcount according to [RFC6551]. Note that this is solely for Use Hopcount according to [RFC6551]. Note that this is solely for
diagnostic purposes as it is not used by the objective function. diagnostic purposes as it is not used by the objective function.
6.11.1.6. Objective Function 6.12.1.6. Objective Function
Objective Function (OF): Use OF0 [RFC6552]. No use of metric Objective Function (OF): Use OF0 [RFC6552]. No use of metric
containers. containers.
rank_factor: Derived from link speed: <= 100Mbps: rank_factor: Derived from link speed: <= 100Mbps:
LOW_SPEED_FACTOR(5), else HIGH_SPEED_FACTOR(1) LOW_SPEED_FACTOR(5), else HIGH_SPEED_FACTOR(1)
This is a simple rank differentiation between typical "low speed" or This is a simple rank differentiation between typical "low speed" or
"IoT" links that commonly max out at 100 Mbps and typical "IoT" links that commonly max out at 100 Mbps and typical
infrastructure links with speeds of 1 Gbps or higher. Given how the infrastructure links with speeds of 1 Gbps or higher. Given how the
path selection for the ACP focusses only on reachability but not on path selection for the ACP focusses only on reachability but not on
path cost optimization, no attempts at finer grained path path cost optimization, no attempts at finer grained path
optimization are made. optimization are made.
6.11.1.7. DODAG Repair 6.12.1.7. DODAG Repair
Global Repair: we assume stable links and ranks (metrics), so no need Global Repair: we assume stable links and ranks (metrics), so there
to periodically rebuild DODAG. DODAG version only incremented under is no need to periodically rebuild the DODAG. The DODAG version is
catastrophic events (e.g., administrative action). only incremented under catastrophic events (e.g., administrative
action).
Local Repair: As soon as link breakage is detected, send No-Path DAO Local Repair: As soon as link breakage is detected, the ACP node send
for all the targets that were reachable only via this link. As soon No-Path DAO for all the targets that were reachable only via this
as link repair is detected, validate if this link provides you a link. As soon as link repair is detected, the ACP node validates if
better parent. If so, compute your new rank, and send new DIO that this link provides a better parent. If so, a new rank is computed by
advertises your new rank. Then send a DAO with a new path sequence the ACP node and it sends new DIO that advertise the new rank. Then
about yourself. it sends a DAO with a new path sequence about itself.
When using ACP multi-access virtual interfaces, local repair can be When using ACP multi-access virtual interfaces, local repair can be
directly by peer breakage, see Section 6.12.5.2.2. triggered directly by peer breakage, see Section 6.13.5.2.2.
stretch_rank: none provided ("not stretched"). stretch_rank: none provided ("not stretched").
Data Path Validation: Not used. Data Path Validation: Not used.
Trickle: Not used. Trickle: Not used.
6.11.1.8. Multicast 6.12.1.8. Multicast
Not used yet but possible because of the selected mode of operations. Not used yet but possible because of the selected mode of operations.
6.11.1.9. Security 6.12.1.9. Security
[RFC6550] security not used, substituted by ACP security. [RFC6550] security not used, substituted by ACP security.
Because the ACP links already include provisions for confidentiality Because the ACP links already include provisions for confidentiality
and integrity protection, their usage at the RPL layer would be and integrity protection, their usage at the RPL layer would be
redundant, and so RPL security is not used. redundant, and so RPL security is not used.
6.11.1.10. P2P communications 6.12.1.10. P2P communications
Not used. Not used.
6.11.1.11. IPv6 address configuration 6.12.1.11. IPv6 address configuration
Every ACP node (RPL node) announces an IPv6 prefix covering the Every ACP node (RPL node) announces an IPv6 prefix covering the
address(es) used in the ACP node. The prefix length depends on the addresses assigned to the ACP node via the AcpNodeName. The prefix
chosen addressing sub-scheme of the ACP address provisioned into the length depends on the addressing sub-scheme of the acp-address, /127
certificate of the ACP node, e.g., /127 for Zone Addressing Sub- for Zone Addressing Sub-Scheme and /112 or /120 for Vlong addressing
Scheme or /112 or /120 for Vlong addressing sub-scheme. See sub-scheme. See Section 6.11 for more details.
Section 6.10 for more details.
Every ACP node MUST install a black hole (aka null) route for Every ACP node MUST install a black hole (aka null) route if there
whatever ACP address space that it advertises (i.e.: the /96 or are unused parts of the ACP address space assigned to the ACP node
/127). This is avoid routing loops for addresses that an ACP node via its AcpNodeName. This is superceeded by longer prefixes assigned
has not (yet) used. to interfaces for the address space actually used by the node. For
example, when the node has an ACP-VLong-8 address space, it installs
a /120 black hole route. If it then for example only uses the ACP
address (first address from the space), it would assign that address
via a /128 address prefix to the ACP loopback interface (see
Section 6.13.5.1). None of those longer prefixes are announced into
RPL.
6.11.1.12. Administrative parameters For ACP-Manual address prefixes configured on an ACP node, for
example for ACP connect subnets (see Section 8.1.1), the node
announces the /64 subnet prefix.
6.12.1.12. Administrative parameters
Administrative Preference ([RFC6550], 3.2.6 - to become root): Administrative Preference ([RFC6550], 3.2.6 - to become root):
Indicated in DODAGPreference field of DIO message. Indicated in DODAGPreference field of DIO message.
o Explicit configured "root": 0b100 * Explicit configured "root": 0b100
* ACP registrar (Default): 0b011
o ACP registrar (Default): 0b011 * ACP-connect (non-registrar): 0b010
* Default: 0b001.
o ACP-connect (non-registrar): 0b010
o Default: 0b001.
6.11.1.13. RPL Packet Information 6.12.1.13. RPL Packet Information
RPI is not required in the ACP RPL profile for the following reasons. RPI is not required in the ACP RPL profile for the following reasons.
One RPI option is the RPL Source Routing Header (SRH) [RFC6554] which One RPI option is the RPL Source Routing Header (SRH) [RFC6554] which
is not necessary because the ACP RPL profile uses storing mode where is not necessary because the ACP RPL profile uses storing mode where
each hop has the necessary next-hop forwarding information. each hop has the necessary next-hop forwarding information.
The simpler RPL Option header [RFC6553] is also not necessary in this The simpler RPL Option header [RFC6553] is also not necessary in this
profile, because it uses a single RPL instance and data path profile, because it uses a single RPL instance and data path
validation is also not used. validation is also not used.
6.11.1.14. Unknown Destinations 6.12.1.14. Unknown Destinations
Because RPL minimizes the size of the routing and forwarding table, Because RPL minimizes the size of the routing and forwarding table,
prefixes reachable through the same interface as the RPL root are not prefixes reachable through the same interface as the RPL root are not
known on every ACP node. Therefore traffic to unknown destination known on every ACP node. Therefore traffic to unknown destination
addresses can only be discovered at the RPL root. The RPL root addresses can only be discovered at the RPL root. The RPL root
SHOULD have attach safe mechanisms to operationally discover and log SHOULD have attach safe mechanisms to operationally discover and log
such packets. such packets.
As this requirement raises additional Data-Plane, it does not apply As this requirement places additional constraints on the Data-Plane
to nodes where the administrative parameter to become root functionality of the RPL root, it does not apply to "normal" nodes
(Section 6.11.1.12) can always only be 0b001, e.g.: the node does not that are not configured to have special functionality (i.e., the
support explicit configuration to be root, or to be ACP registrar or adminstrative parameter from Section 6.12.1.12 has value 0b001). If
to have ACP-connect functionality. If an ACP network is degraded to the ACP network is degraded to the point where there are no nodes
the point where there are no nodes that could be configured roots, that could be configured as root, registrar, or ACP-connect nodes, it
ACP registrars or ACP-connect nodes, traffic to unknown destinations is possible that the RPL root ( and thus the ACP as a whole) would be
could not be diagnosed, but in the absence of any intelligent nodes unable to detect traffic to unknown destinations. However, in the
supporting other than 0b001 administrative preference, there is absence of nodes with administrative preference other than 0b001,
likely also no diagnostic function possible. there is also unlikely to be a way to get diagnostic information out
of the ACP, so detection of traffic to unknown destinations would not
be actionable anyway.
6.12. General ACP Considerations 6.13. General ACP Considerations
Since channels are by default established between adjacent neighbors, Since channels are by default established between adjacent neighbors,
the resulting overlay network does hop-by-hop encryption. Each node the resulting overlay network does hop-by-hop encryption. Each node
decrypts incoming traffic from the ACP, and encrypts outgoing traffic decrypts incoming traffic from the ACP, and encrypts outgoing traffic
to its neighbors in the ACP. Routing is discussed in Section 6.11. to its neighbors in the ACP. Routing is discussed in Section 6.12.
6.12.1. Performance 6.13.1. Performance
There are no performance requirements against ACP implementations There are no performance requirements against ACP implementations
defined in this document because the performance requirements depend defined in this document because the performance requirements depend
on the intended use case. It is expected that full autonomic node on the intended use case. It is expected that full autonomic node
with a wide range of ASA can require high forwarding plane with a wide range of ASA can require high forwarding plane
performance in the ACP, for example for telemetry. Implementations performance in the ACP, for example for telemetry. Implementations
of ACP to solely support traditional/SDN style use cases can benefit of ACP to solely support traditional/SDN style use cases can benefit
from ACP at lower performance, especially if the ACP is used only for from ACP at lower performance, especially if the ACP is used only for
critical operations, e.g., when the Data-Plane is not available. The critical operations, e.g., when the Data-Plane is not available. The
design of the ACP as specified in this document is intended to design of the ACP as specified in this document is intended to
support a wide range of performance options: It is intended to allow support a wide range of performance options: It is intended to allow
software-only implementations at potentially low performance, but can software-only implementations at potentially low performance, but can
also support high performance options. See [RFC8368] for more also support high performance options. See [RFC8368] for more
details. details.
6.12.2. Addressing of Secure Channels 6.13.2. Addressing of Secure Channels
In order to be independent of the Data-Plane routing and addressing, In order to be independent of the Data-Plane routing and addressing,
the GRASP discovered ACP secure channels use IPv6 link local the GRASP discovered ACP secure channels use IPv6 link local
addresses between adjacent neighbors. Note: Section 8.2 specifies addresses between adjacent neighbors. Note: Section 8.2 specifies
extensions in which secure channels are configured tunnels operating extensions in which secure channels are configured tunnels operating
over the Data-Plane, so those secure channels cannot be independent over the Data-Plane, so those secure channels cannot be independent
of the Data-Plane. of the Data-Plane.
To avoid that Data-Plane configuration can impact the operations of To avoid that Data-Plane configuration can impact the operations of
the IPv6 (link-local) interface/address used for ACP channels, the IPv6 (link-local) interface/address used for ACP channels,
skipping to change at page 80, line 5 skipping to change at page 81, line 17
(virtual) interface with a separate IPv6 link-local address can be (virtual) interface with a separate IPv6 link-local address can be
used. For example, the ACP interface could be run over a separate used. For example, the ACP interface could be run over a separate
MAC address of an underlying L2 (Ethernet) interface. For more MAC address of an underlying L2 (Ethernet) interface. For more
details and options, see Appendix A.10.2. details and options, see Appendix A.10.2.
Note that other (non-ideal) implementation choices may introduce Note that other (non-ideal) implementation choices may introduce
additional undesired dependencies against the Data-Plane. For additional undesired dependencies against the Data-Plane. For
example shared code and configuration of the secure channel protocols example shared code and configuration of the secure channel protocols
(IPsec / DTLS). (IPsec / DTLS).
6.12.3. MTU 6.13.3. MTU
The MTU for ACP secure channels MUST be derived locally from the The MTU for ACP secure channels MUST be derived locally from the
underlying link MTU minus the secure channel encapsulation overhead. underlying link MTU minus the secure channel encapsulation overhead.
ACP secure Channel protocols do not need to perform MTU discovery ACP secure Channel protocols do not need to perform MTU discovery
because they are built across L2 adjacencies - the MTU on both sides because they are built across L2 adjacencies - the MTU on both sides
connecting to the L2 connection are assumed to be consistent. connecting to the L2 connection are assumed to be consistent.
Extensions to ACP where the ACP is for example tunneled need to Extensions to ACP where the ACP is for example tunneled need to
consider how to guarantee MTU consistency. This is an issue of consider how to guarantee MTU consistency. This is an issue of
tunnels, not an issue of running the ACP across a tunnel. Transport tunnels, not an issue of running the ACP across a tunnel. Transport
stacks running across ACP can perform normal PMTUD (Path MTU stacks running across ACP can perform normal PMTUD (Path MTU
Discovery). Because the ACP is meant to be prioritize reliability Discovery). Because the ACP is meant to prioritize reliability over
over performance, they MAY opt to only expect IPv6 minimum MTU (1280) performance, they MAY opt to only expect IPv6 minimum MTU (1280) to
to avoid running into PMTUD implementation bugs or underlying link avoid running into PMTUD implementation bugs or underlying link MTU
MTU mismatch problems. mismatch problems.
6.12.4. Multiple links between nodes 6.13.4. Multiple links between nodes
If two nodes are connected via several links, the ACP SHOULD be If two nodes are connected via several links, the ACP SHOULD be
established across every link, but it is possible to establish the established across every link, but it is possible to establish the
ACP only on a sub-set of links. Having an ACP channel on every link ACP only on a sub-set of links. Having an ACP channel on every link
has a number of advantages, for example it allows for a faster has a number of advantages, for example it allows for a faster
failover in case of link failure, and it reflects the physical failover in case of link failure, and it reflects the physical
topology more closely. Using a subset of links (for example, a topology more closely. Using a subset of links (for example, a
single link), reduces resource consumption on the node, because state single link), reduces resource consumption on the node, because state
needs to be kept per ACP channel. The negotiation scheme explained needs to be kept per ACP channel. The negotiation scheme explained
in Section 6.5 allows Alice (the node with the higher ACP address) to in Section 6.6 allows the Decider (the node with the higher ACP
drop all but the desired ACP channels to Bob - and Bob will not re- address) to drop all but the desired ACP channels to the Follower -
try to build these secure channels from his side unless Alice shows and the Follower will not re-try to build these secure channels from
up with a previously unknown GRASP announcement (e.g., on a different its side unless the Decider shows up with a previously unknown GRASP
link or with a different address announced in GRASP). announcement (e.g., on a different link or with a different address
announced in GRASP).
6.12.5. ACP interfaces 6.13.5. ACP interfaces
The ACP VRF has conceptually two type of interfaces: The "ACP The ACP VRF has conceptually two type of interfaces: The "ACP
Loopback interface(s)" to which the ACP ULA address(es) are assigned Loopback interface(s)" to which the ACP ULA address(es) are assigned
and the "ACP virtual interfaces" that are mapped to the ACP secure and the "ACP virtual interfaces" that are mapped to the ACP secure
channels. channels.
6.12.5.1. ACP loopback interfaces 6.13.5.1. ACP loopback interfaces
For autonomous operations of the ACP, as described in Section 6 and For autonomous operations of the ACP, as described in Section 6 and
Section 7, the ACP node uses the first address from the N bit ACP Section 7, the ACP node uses the first address from the N bit ACP
prefix (N = 128 - number of Vbits of the ACP address) assigned to the prefix (N = 128 - number of Vbits of the ACP address) assigned to the
node. This address is assigned with an adddress prefix of N or node. This address is assigned with an address prefix of N or larger
larger to a loopback interface. to a loopback interface.
Other addresses from the prefix can be used by the ACP of the node as Other addresses from the prefix can be used by the ACP of the node as
desired. The autonomous operations of the ACP does not require desired. The autonomous operations of the ACP does not require
additional global scope IPv6 addresses, they are instead intended for additional global scope IPv6 addresses, they are instead intended for
ASA or non-autonomous functions. Non fully autonomic components of ASA or non-autonomous functions. Non fully autonomic components of
the ACP such as ACP connect interfaces (see Figure 15 may also the ACP such as ACP connect interfaces (see Figure 16) may also
introduce additional global scope IPv6 addresses on other type of introduce additional global scope IPv6 addresses on other types of
interfaces into the ACP. interfaces into the ACP.
[RFC Editor: please remove this paragraph: Note to reviewers: Please [RFC Editor: please remove this paragraph: Note to reviewers: Please
do not complain again about an obsolete RFC number in the following do not complain again about an obsolete RFC number in the following
paragraph. The text should make it clear that the reference was paragraph. The text should make it clear that the reference was
choosen to indicate a particular point in time, but not to recommend/ choosen to indicate a particular point in time, but not to recommend/
use a particularily obsolete protocol spec.] use a particularily obsolete protocol spec.]
The use of loopback interfaces for global scope addresses is common The use of loopback interfaces for global scope addresses is common
operational configuration practice on routers, for example in IBGP operational configuration practice on routers, for example in IBGP
skipping to change at page 81, line 47 skipping to change at page 83, line 15
A loopback interface used for the ACP MUST NOT have connectivity to A loopback interface used for the ACP MUST NOT have connectivity to
other nodes. other nodes.
The following reviews the reasons for the choice of loopback The following reviews the reasons for the choice of loopback
addresses for ACP addresses is based on the IPv6 address architecture addresses for ACP addresses is based on the IPv6 address architecture
and common challenges: and common challenges:
1. IPv6 addresses are assigned to interfaces, not nodes. IPv6 1. IPv6 addresses are assigned to interfaces, not nodes. IPv6
continues the IPv4 model that a subnet prefix is associated with continues the IPv4 model that a subnet prefix is associated with
one link, see [RFC4291], Section 2.1. one link, see [RFC4291], Section 2.1.
2. IPv6 implementations commonly do not allow assignment of the same
2. IPv6 implementations do commonly not allow to assign the same
IPv6 global scope address in the same VRF to more than one IPv6 global scope address in the same VRF to more than one
interface. interface.
3. Global scope addresses assigned to interfaces that are connecting 3. Global scope addresses assigned to interfaces that are connecting
to other nodes (external interfaces) may not be stable addresses to other nodes (external interfaces) may not be stable addresses
for communications because any such interface could fail due to for communications because any such interface could fail due to
reasons external to the node. This could render the addresses reasons external to the node. This could render the addresses
assigned to that interface unusable. assigned to that interface unusable.
4. If failure of the subnet does not result in bringing down the 4. If failure of the subnet does not result in bringing down the
interface and making the addresses unusable, it could result in interface and making the addresses unusable, it could result in
unreachability of the address because the shortest path to the unreachability of the address because the shortest path to the
node might go through one of the other nodes on the same subnet node might go through one of the other nodes on the same subnet
which could equally consider the subnet to be operational even which could equally consider the subnet to be operational even
though it is not. though it is not.
5. Many OAM service implementations on routers can not deal with 5. Many OAM service implementations on routers can not deal with
more than one peer address, often because they do already expect more than one peer address, often because they do already expect
that a single loopback address can be used, especially to provide that a single loopback address can be used, especially to provide
a stable address under failure of external interfaces or links. a stable address under failure of external interfaces or links.
6. Even when an application supports multiple addresses to a peer, 6. Even when an application supports multiple addresses to a peer,
it can only use one adddress for a connection at a time with the it can only use one address for a connection at a time with the
most widely deployed transport protocols TCP and UDP. While most widely deployed transport protocols TCP and UDP. While
[RFC6824] solves this problem, it is not widely adopted for [RFC6824] solves this problem, it is not widely adopted for
router OAM services implementations. router OAM services implementations.
7. To completely autonomously assign global scope addresses to 7. To completely autonomously assign global scope addresses to
subnets connecting to other nodes, it would be necessary for subnets connecting to other nodes, it would be necessary for
every node to have an amount of prefix address space in the order every node to have an amount of prefix address space in the order
of the maximum number of subnets that the node could connect to of the maximum number of subnets that the node could connect to
and then the node would have to negotiate with adjacent nodes and then the node would have to negotiate with adjacent nodes
across those subnet whose address space to use for each subnet. across those subnet whose address space to use for each subnet.
8. Using global scope addresses for subnets between nodes is 8. Using global scope addresses for subnets between nodes is
unnecessary if those subnets only connect routers, such as ACP unnecessary if those subnets only connect routers, such as ACP
secure channels because they can communicate to remote nodes via secure channels, because they can communicate to remote nodes via
their global scope loopback addresses. Using global scope their global scope loopback addresses. Using global scope
addresses for those extern subnets is therefore wasteful for the addresses for those extern subnets is therefore wasteful for the
address space and also unnecessarily increasing the size of address space and also unnecessarily increasing the size of
routing and forwarding tables, which especially for the ACP is routing and forwarding tables, which especially for the ACP is
highly undesirable because it should attempt to minimize the per- highly undesirable because it should attempt to minimize the per-
node overhead of the ACP VRF. node overhead of the ACP VRF.
9. For all these reasons, the ACP addressing schemes do not consider 9. For all these reasons, the ACP addressing schemes do not consider
ACP addresses for subnets connecting ACP nodes. ACP addresses for subnets connecting ACP nodes.
Note that [RFC8402] introduces the term Node-SID to refer to IGP Note that [RFC8402] introduces the term Node-SID to refer to IGP
prefix segments that identify a specific rouer, for example on a prefix segments that identify a specific rouer, for example on a
loopback interface. An ACP loopback address prefix may similarily be loopback interface. An ACP loopback address prefix may similarily be
called an ACP Node Identifier. called an ACP Node Identifier.
6.12.5.2. ACP virtual interfaces 6.13.5.2. ACP virtual interfaces
Any ACP secure channel to another ACP node is mapped to ACP virtual Any ACP secure channel to another ACP node is mapped to ACP virtual
interfaces in one of the following ways. This is independent of the interfaces in one of the following ways. This is independent of the
chosen secure channel protocol (IPsec, DTLS or other future protocol chosen secure channel protocol (IPsec, DTLS or other future protocol
- standards or non-standards). - standards or non-standards).
Note that all the considerations described here are assuming point- Note that all the considerations described here are assuming point-
to-point secure channel associations. Mapping multi-party secure to-point secure channel associations. Mapping multi-party secure
channel associations such as [RFC6407] is out of scope (but would be channel associations such as [RFC6407] is out of scope.
easy to add).
6.12.5.2.1. ACP point-to-point virtual interfaces 6.13.5.2.1. ACP point-to-point virtual interfaces
In this option, each ACP secure channel is mapped into a separate In this option, each ACP secure channel is mapped into a separate
point-to-point ACP virtual interface. If a physical subnet has more point-to-point ACP virtual interface. If a physical subnet has more
than two ACP capable nodes (in the same domain), this implementation than two ACP capable nodes (in the same domain), this implementation
approach will lead to a full mesh of ACP virtual interfaces between approach will lead to a full mesh of ACP virtual interfaces between
them. them.
When the secure channel protocol determines a peer to be dead, this When the secure channel protocol determines a peer to be dead, this
SHOULD result in indicating link breakage to trigger RPL DODAG SHOULD result in indicating link breakage to trigger RPL DODAG
repair, see Section 6.11.1.7. repair, see Section 6.12.1.7.
6.12.5.2.2. ACP multi-access virtual interfaces 6.13.5.2.2. ACP multi-access virtual interfaces
In a more advanced implementation approach, the ACP will construct a In a more advanced implementation approach, the ACP will construct a
single multi-access ACP virtual interface for all ACP secure channels single multi-access ACP virtual interface for all ACP secure channels
to ACP capable nodes reachable across the same underlying (physical) to ACP capable nodes reachable across the same underlying (physical)
subnet. IPv6 link-local multicast packets sent into an ACP multi- subnet. IPv6 link-local multicast packets sent into an ACP multi-
access virtual interface are replicated to every ACP secure channel access virtual interface are replicated to every ACP secure channel
mapped into the ACP multicast-access virtual interface. IPv6 unicast mapped into the ACP multicast-access virtual interface. IPv6 unicast
packets sent into an ACP multi-access virtual interface are sent to packets sent into an ACP multi-access virtual interface are sent to
the ACP secure channel that belongs to the ACP neighbor that is the the ACP secure channel that belongs to the ACP neighbor that is the
next-hop in the ACP forwarding table entry used to reach the packets next-hop in the ACP forwarding table entry used to reach the packets
destination address. destination address.
When the secure channel protocol determines a peer to be dead for a When the secure channel protocol determines a peer to be dead for a
secure channel mapped into an ACP multi-access virtual interface, secure channel mapped into an ACP multi-access virtual interface,
this SHOULD result in signaling breakage of that peer to RPL, so it this SHOULD result in signaling breakage of that peer to RPL, so it
can trigger RPL DODAG repair, see Section 6.11.1.7. can trigger RPL DODAG repair, see Section 6.12.1.7.
There is no requirement for all ACP nodes on the same multi-access There is no requirement for all ACP nodes on the same multi-access
subnet to use the same type of ACP virtual interface. This is purely subnet to use the same type of ACP virtual interface. This is purely
a node local decision. a node local decision.
ACP nodes MUST perform standard IPv6 operations across ACP virtual ACP nodes MUST perform standard IPv6 operations across ACP virtual
interfaces including SLAAC (Stateless Address Auto-Configuration) - interfaces including SLAAC (Stateless Address Auto-Configuration) -
[RFC4862]) to assign their IPv6 link local address on the ACP virtual [RFC4862]) to assign their IPv6 link local address on the ACP virtual
interface and ND (Neighbor Discovery - [RFC4861]) to discover which interface and ND (Neighbor Discovery - [RFC4861]) to discover which
IPv6 link-local neighbor address belongs to which ACP secure channel IPv6 link-local neighbor address belongs to which ACP secure channel
mapped to the ACP virtual interface. This is independent of whether mapped to the ACP virtual interface. This is independent of whether
the ACP virtual interface is point-to-point or multi-access. the ACP virtual interface is point-to-point or multi-access.
"Optimistic Duplicate Address Detection (DAD)" according to [RFC4429] "Optimistic Duplicate Address Detection (DAD)" according to [RFC4429]
is RECOMMENDED because the likelihood for duplicates between ACP is RECOMMENDED because the likelihood for duplicates between ACP
nodes is highly improbable as long as the address can be formed from nodes is highly improbable as long as the address can be formed from
a globally unique local assigned identifier (e.g., EUI-48/EUI-64, see a globally unique local assigned identifier (e.g., EUI-48/EUI-64, see
skipping to change at page 85, line 7 skipping to change at page 86, line 11
example simpler to build services with topology awareness inside the example simpler to build services with topology awareness inside the
ACP VRF in the same way as they could have been built running ACP VRF in the same way as they could have been built running
natively on the multi-access interfaces. natively on the multi-access interfaces.
Consider also the impact of point-to-point vs. multi-access virtual Consider also the impact of point-to-point vs. multi-access virtual
interface on the efficiency of flooding via link local multicasted interface on the efficiency of flooding via link local multicasted
messages: messages:
Assume a LAN with three ACP neighbors, Alice, Bob and Carol. Alice's Assume a LAN with three ACP neighbors, Alice, Bob and Carol. Alice's
ACP GRASP wants to send a link-local GRASP multicast message to Bob ACP GRASP wants to send a link-local GRASP multicast message to Bob
and Carol. If Alice's ACP emulates the LAN as one point-to-point and Carol. If Alice's ACP emulates the LAN as per-peer, point-to-
virtual interface to Bob and one to Carol, The sending applications point virtual interfaces, one to Bob and one to Carol, Alice's ACP
itself will send two copies, if Alice's ACP emulates a LAN, GRASP GRASP will send two copies of multicast GRASP messages: One to Bob
will send one packet and the ACP will replicate it. The result is and one to Carol. If Alice's ACP emulates a LAN via a multipoint
the same. The difference happens when Bob and Carol receive their virtual interface, Alice's ACP GRASP will send one packet to that
interface and the ACP multipoint virtual interface will replicate the
packet to each secure channel, one to Bob, one to Carol. The result
is the same. The difference happens when Bob and Carol receive their
packet. If they use ACP point-to-point virtual interfaces, their packet. If they use ACP point-to-point virtual interfaces, their
GRASP instance would forward the packet from Alice to each other as GRASP instance would forward the packet from Alice to each other as
part of the GRASP flooding procedure. These packets are unnecessary part of the GRASP flooding procedure. These packets are unnecessary
and would be discarded by GRASP on receipt as duplicates (by use of and would be discarded by GRASP on receipt as duplicates (by use of
the GRASP Session ID). If Bob and Carol's ACP would emulate a multi- the GRASP Session ID). If Bob and Carol's ACP would emulate a multi-
access virtual interface, then this would not happen, because GRASPs access virtual interface, then this would not happen, because GRASPs
flooding procedure does not replicate back packets to the interface flooding procedure does not replicate back packets to the interface
that they were received from. that they were received from.
Note that link-local GRASP multicast messages are not sent directly Note that link-local GRASP multicast messages are not sent directly
as IPv6 link-local multicast UDP messages into ACP virtual as IPv6 link-local multicast UDP messages into ACP virtual
interfaces, but instead into ACP GRASP virtual interfaces, that are interfaces, but instead into ACP GRASP virtual interfaces, that are
layered on top of ACP virtual interfaces to add TCP reliability to layered on top of ACP virtual interfaces to add TCP reliability to
link-local multicast GRASP messages. Nevertheless, these ACP GRASP link-local multicast GRASP messages. Nevertheless, these ACP GRASP
virtual interfaces perform the same replication of message and, virtual interfaces perform the same replication of message and,
therefore, result in the same impact on flooding. See Section 6.8.2 therefore, result in the same impact on flooding. See Section 6.9.2
for more details. for more details.
RPL does support operations and correct routing table construction RPL does support operations and correct routing table construction
across non-broadcast multi-access (NBMA) subnets. This is common across non-broadcast multi-access (NBMA) subnets. This is common
when using many radio technologies. When such NBMA subnets are used, when using many radio technologies. When such NBMA subnets are used,
they MUST NOT be represented as ACP multi-access virtual interfaces they MUST NOT be represented as ACP multi-access virtual interfaces
because the replication of IPv6 link-local multicast messages will because the replication of IPv6 link-local multicast messages will
not reach all NBMA subnet neighbors. In result, GRASP message not reach all NBMA subnet neighbors. In result, GRASP message
flooding would fail. Instead, each ACP secure channel across such an flooding would fail. Instead, each ACP secure channel across such an
interface MUST be represented as a ACP point-to-point virtual interface MUST be represented as a ACP point-to-point virtual
skipping to change at page 86, line 4 skipping to change at page 87, line 6
interface. See also Appendix A.10.4. interface. See also Appendix A.10.4.
Care needs to be taken when creating multi-access ACP virtual Care needs to be taken when creating multi-access ACP virtual
interfaces across ACP secure channels between ACP nodes in different interfaces across ACP secure channels between ACP nodes in different
domains or routing subdomains. If for example future inter-domain domains or routing subdomains. If for example future inter-domain
ACP policies are defined as "peer-to-peer" policies, it is easier to ACP policies are defined as "peer-to-peer" policies, it is easier to
create ACP point-to-point virtual interfaces for these inter-domain create ACP point-to-point virtual interfaces for these inter-domain
secure channels. secure channels.
7. ACP support on L2 switches/ports (Normative) 7. ACP support on L2 switches/ports (Normative)
7.1. Why (Benefits of ACP on L2 switches) 7.1. Why (Benefits of ACP on L2 switches)
ANrtr1 ------ ANswitch1 --- ANswitch2 ------- ANrtr2 ANrtr1 ------ ANswitch1 --- ANswitch2 ------- ANrtr2
.../ \ \ ... .../ \ \ ...
ANrtrM ------ \ ------- ANrtrN ANrtrM ------ \ ------- ANrtrN
ANswitchM ... ANswitchM ...
Figure 14: Topology with L2 ACP switches Figure 15: Topology with L2 ACP switches
Consider a large L2 LAN with ANrtr1...ANrtrN connected via some Consider a large L2 LAN with ANrtr1...ANrtrN connected via some
topology of L2 switches. Examples include large enterprise campus topology of L2 switches. Examples include large enterprise campus
networks with an L2 core, IoT networks or broadband aggregation networks with an L2 core, IoT networks or broadband aggregation
networks which often have even a multi-level L2 switched topology. networks which often have even a multi-level L2 switched topology.
If the discovery protocol used for the ACP is operating at the subnet If the discovery protocol used for the ACP is operating at the subnet
level, every ACP router will see all other ACP routers on the LAN as level, every ACP router will see all other ACP routers on the LAN as
neighbors and a full mesh of ACP channels will be built. If some or neighbors and a full mesh of ACP channels will be built. If some or
all of the AN switches are autonomic with the same discovery all of the AN switches are autonomic with the same discovery
skipping to change at page 87, line 39 skipping to change at page 88, line 40
L3 VLAN interface. With the aforementioned changes for DULL GRASP, L3 VLAN interface. With the aforementioned changes for DULL GRASP,
ACP can simply operate on the L3 VLAN interfaces, so no further ACP can simply operate on the L3 VLAN interfaces, so no further
(hardware) forwarding changes are required to make ACP operate on L2 (hardware) forwarding changes are required to make ACP operate on L2
ports. This is possible because the ACP secure channel protocols ports. This is possible because the ACP secure channel protocols
only use link-local IPv6 unicast packets, and these packets will be only use link-local IPv6 unicast packets, and these packets will be
sent to the correct L2 port towards the peer by the VLAN logic of the sent to the correct L2 port towards the peer by the VLAN logic of the
device. device.
This is sufficient when p2p ACP virtual interfaces are established to This is sufficient when p2p ACP virtual interfaces are established to
every ACP peer. When it is desired to create multi-access ACP every ACP peer. When it is desired to create multi-access ACP
virtual interfaces (see Section 6.12.5.2.2), it is REQIURED not to virtual interfaces (see Section 6.13.5.2.2), it is REQIURED not to
coalesce all the ACP secure channels on the same L3 VLAN interface, coalesce all the ACP secure channels on the same L3 VLAN interface,
but only all those on the same L2 port. but only all those on the same L2 port.
If VLAN tagging is used, then all the above described logic only If VLAN tagging is used, then all the above described logic only
applies to untagged GRASP packets. For the purpose of ACP neighbor applies to untagged GRASP packets. For the purpose of ACP neighbor
discovery via GRASP, no VLAN tagged packets SHOULD be sent or discovery via GRASP, no VLAN tagged packets SHOULD be sent or
received. In a hybrid L2/L3 switch, each VLAN would therefore only received. In a hybrid L2/L3 switch, each VLAN would therefore only
create ACP adjacencies across those ports where the VLAN is carried create ACP adjacencies across those ports where the VLAN is carried
untagged. untagged.
skipping to change at page 89, line 23 skipping to change at page 90, line 28
nodes, an ACP node SHOULD support "ACP connect" (sometimes also nodes, an ACP node SHOULD support "ACP connect" (sometimes also
called "autonomic connect"): called "autonomic connect"):
"ACP connect" is an interface level configured workaround for "ACP connect" is an interface level configured workaround for
connection of trusted non-ACP nodes to the ACP. The ACP node on connection of trusted non-ACP nodes to the ACP. The ACP node on
which ACP connect is configured is called an "ACP edge node". With which ACP connect is configured is called an "ACP edge node". With
ACP connect, the ACP is accessible from those non-ACP nodes (such as ACP connect, the ACP is accessible from those non-ACP nodes (such as
NOC systems) on such an interface without those non-ACP nodes having NOC systems) on such an interface without those non-ACP nodes having
to support any ACP discovery or ACP channel setup. This is also to support any ACP discovery or ACP channel setup. This is also
called "native" access to the ACP because to those NOC systems the called "native" access to the ACP because to those NOC systems the
interface looks like a normal network interface (without any interface looks like a normal network interface without any ACP
encryption/novel-signaling). secure channel that is encapsulating the traffic.
Data-Plane "native" (no ACP) Data-Plane "native" (no ACP)
. .
+--------+ +----------------+ . +-------------+ +--------+ +----------------+ . +-------------+
| ACP | |ACP Edge Node | . | | | ACP | |ACP Edge Node | . | |
| Node | | | v | | | Node | | | v | |
| |-------|...[ACP VRF]....+-----------------| |+ | |-------|...[ACP VRF]....+----------------| |+
| | ^ |. | | NOC Device || | | ^ |. | | NOC Device ||
| | . | .[Data-Plane]..+-----------------| "NMS hosts" || | | . | .[Data-Plane]..+----------------| "NMS hosts" ||
| | . | [ ] | . ^ | || | | . | [ ] | . ^ | ||
+--------+ . +----------------+ . . +-------------+| +--------+ . +----------------+ . . +-------------+|
. . . +-------------+ . . . +-------------+
. . . . . .
Data-Plane "native" . ACP "native" (unencrypted) Data-Plane "native" . ACP "native" (unencrypted)
+ ACP auto-negotiated . "ACP connect subnet" + ACP auto-negotiated . "ACP connect subnet"
and encrypted . and encrypted .
ACP connect interface ACP connect interface
e.g., "VRF ACP native" (config) e.g., "VRF ACP native" (config)
Figure 15: ACP connect Figure 16: ACP connect
ACP connect has security consequences: All systems and processes ACP connect has security consequences: All systems and processes
connected via ACP connect have access to all ACP nodes on the entire connected via ACP connect have access to all ACP nodes on the entire
ACP, without further authentication. Thus, the ACP connect interface ACP, without further authentication. Thus, the ACP connect interface
and NOC systems connected to it needs to be physically controlled/ and NOC systems connected to it needs to be physically controlled/
secured. For this reason the mechanisms described here do explicitly secured. For this reason the mechanisms described here do explicitly
not include options to allow for a non-ACP router to be connected not include options to allow for a non-ACP router to be connected
across an ACP connect interface and addresses behind such a router across an ACP connect interface and addresses behind such a router
routed inside the ACP. routed inside the ACP.
skipping to change at page 90, line 26 skipping to change at page 91, line 31
An ACP connect interface provides exclusively access to only the ACP. An ACP connect interface provides exclusively access to only the ACP.
This is likely insufficient for many NMS hosts. Instead, they would This is likely insufficient for many NMS hosts. Instead, they would
require a second "Data-Plane" interface outside the ACP for require a second "Data-Plane" interface outside the ACP for
connections between the NMS host and administrators, or Internet connections between the NMS host and administrators, or Internet
based services, or for direct access to the Data-Plane. The document based services, or for direct access to the Data-Plane. The document
"Using Autonomic Control Plane for Stable Connectivity of Network "Using Autonomic Control Plane for Stable Connectivity of Network
OAM" [RFC8368] explains in more detail how the ACP can be integrated OAM" [RFC8368] explains in more detail how the ACP can be integrated
in a mixed NOC environment. in a mixed NOC environment.
An ACP connect interface SHOULD use an IPv6 address/prefix from the An ACP connect interface SHOULD use an IPv6 address/prefix from the
ACP Manual Addressing Sub-Scheme (Section 6.10.4), letting the ACP Manual Addressing Sub-Scheme (Section 6.11.4), letting the
operator configure for example only the Subnet-ID and having the node operator configure for example only the Subnet-ID and having the node
automatically assign the remaining part of the prefix/address. It automatically assign the remaining part of the prefix/address. It
SHOULD NOT use a prefix that is also routed outside the ACP so that SHOULD NOT use a prefix that is also routed outside the ACP so that
the addresses clearly indicate whether it is used inside the ACP or the addresses clearly indicate whether it is used inside the ACP or
not. not.
The prefix of ACP connect subnets MUST be distributed by the ACP edge The prefix of ACP connect subnets MUST be distributed by the ACP edge
node into the ACP routing protocol RPL. The NMS hosts MUST connect node into the ACP routing protocol RPL. The NMS hosts MUST connect
to prefixes in the ACP routing table via its ACP connect interface. to prefixes in the ACP routing table via its ACP connect interface.
In the simple case where the ACP uses only one ULA prefix and all ACP In the simple case where the ACP uses only one ULA prefix and all ACP
skipping to change at page 90, line 49 skipping to change at page 92, line 7
towards its different interfaces, ACP and Data-Plane. With RFC6724, towards its different interfaces, ACP and Data-Plane. With RFC6724,
The NMS host will select the ACP connect interface for all addresses The NMS host will select the ACP connect interface for all addresses
in the ACP because any ACP destination address is longest matched by in the ACP because any ACP destination address is longest matched by
the address on the ACP connect interface. If the NMS hosts ACP the address on the ACP connect interface. If the NMS hosts ACP
connect interface uses another prefix or if the ACP uses multiple ULA connect interface uses another prefix or if the ACP uses multiple ULA
prefixes, then the NMS hosts require (static) routes towards the ACP prefixes, then the NMS hosts require (static) routes towards the ACP
interface for these prefixes. interface for these prefixes.
When an ACP Edge node receives a packet from an ACP connect When an ACP Edge node receives a packet from an ACP connect
interface, the ACP Edge node MUST only forward the packet into the interface, the ACP Edge node MUST only forward the packet into the
ACP if the packet has an IPv6 source address from that interface. ACP if the packet has an IPv6 source address from that interface
This is sometimes called "RPF filtering". This MAY be changed (this is sometimes called "RPF filtering"). This filtering rule MAY
through administrative measures. be changed through administrative measures. The more any such
administrative action enable reachability of non ACP nodes to the
ACP, the more this may cause security issues.
To limit the security impact of ACP connect, nodes supporting it To limit the security impact of ACP connect, nodes supporting it
SHOULD implement a security mechanism to allow configuration/use of SHOULD implement a security mechanism to allow configuration/use of
ACP connect interfaces only on nodes explicitly targeted to be ACP connect interfaces only on nodes explicitly targeted to be
deployed with it (those in physically secure locations such as a deployed with it (those in physically secure locations such as a
NOC). For example, the registrar could disable the ability to enable NOC). For example, the registrar could disable the ability to enable
ACP connect on devices during enrollment and that property could only ACP connect on devices during enrollment and that property could only
be changed through re-enrollment. See also Appendix A.10.5. be changed through re-enrollment. See also Appendix A.10.5.
ACP Edge nodes SHOULD have a configurable option to filter packets ACP Edge nodes SHOULD have a configurable option to prohibit packets
with RPI headers (xsee Section 6.11.1.13 across an ACP connect with RPI headers (see Section 6.12.1.13 across an ACP connect
interface. These headers are outside the scope of the RPL profile in interface. These headers are outside the scope of the RPL profile in
this specification but may be used in future extensions of this this specification but may be used in future extensions of this
specification. specification.
8.1.2. Software Components 8.1.2. Software Components
The previous section assumed that ACP Edge node and NOC devices are The previous section assumed that ACP Edge node and NOC devices are
separate physical devices and the ACP connect interface is a physical separate physical devices and the ACP connect interface is a physical
network connection. This section discusses the implication when network connection. This section discusses the implication when
these components are instead software components running on a single these components are instead software components running on a single
skipping to change at page 92, line 22 skipping to change at page 93, line 35
software packages. software packages.
8.1.3. Auto Configuration 8.1.3. Auto Configuration
ACP edge nodes, NMS hosts and software components that as described ACP edge nodes, NMS hosts and software components that as described
in the previous section are meant to be composed via virtual in the previous section are meant to be composed via virtual
interfaces SHOULD support on the ACP connect subnet StateLess Address interfaces SHOULD support on the ACP connect subnet StateLess Address
Autoconfiguration (SLAAC - [RFC4862]) and route auto configuration Autoconfiguration (SLAAC - [RFC4862]) and route auto configuration
according to [RFC4191]. according to [RFC4191].
The ACP edge node acts as the router on the ACP connect subnet, The ACP edge node acts as the router towards the ACP on the ACP
providing the (auto-)configured prefix for the ACP connect subnet to connect subnet, providing the (auto-)configured prefix for the ACP
NMS hosts and/or software components. The ACP edge node uses route connect subnet and (auto-)configured routes into the ACP to NMS hosts
prefix option of RFC4191 to announce the default route (::/) with a and/or software components.
lifetime of 0 and aggregated prefixes for routes in the ACP routing
table with normal lifetimes. This will ensure that the ACP edge node The ACP edge node uses the Route Information Option (RIO) of RFC4191
does not become a default router, but that the NMS hosts and software to announce aggregated prefixes for address prefixes used in the ACP
components will route the prefixes used in the ACP to the ACP edge (with normal RIO lifetimes. In addition, the ACP edge node also uses
a RIO to announce the default route (::/0) with a lifetime of 0.
These RIOs allow to connect Type C hosts to the ACP via an ACP
connect subnet on one interface and another network (Data Plane / NMS
network) on the same or another interface of the Type C host, relying
on other routers than the ACP edge node. The RIOs ensure that these
hosts will only route the prefixes used in the ACP to the ACP edge
node. node.
Type A/B host ignore the RIOs and will consider the ACP node to be
their default router for all destination. This is sufficient when
type A/B hosts only need to connect to the ACP but not other
networks. Attaching Type A/B hosts to both the ACP and other
networks, requires either explicit ACP prefix route configuration on
the Type A/B hosts or the combined ACP/Data-Plane interface on the
ACP edge node, see Section 8.1.4.
Aggregated prefix means that the ACP edge node needs to only announce Aggregated prefix means that the ACP edge node needs to only announce
the /48 ULA prefixes used in the ACP but none of the actual /64 the /48 ULA prefixes used in the ACP but none of the actual /64
(Manual Addressing Sub-Scheme), /127 (ACP Zone Addressing Sub- (Manual Addressing Sub-Scheme), /127 (ACP Zone Addressing Sub-
Scheme), /112 or /120 (Vlong Addressing Sub-Scheme) routes of actual Scheme), /112 or /120 (Vlong Addressing Sub-Scheme) routes of actual
ACP nodes. If ACP interfaces are configured with non ULA prefixes, ACP nodes. If ACP interfaces are configured with non ULA prefixes,
then those prefixes cannot be aggregated without further configured then those prefixes cannot be aggregated without further configured
policy on the ACP edge node. This explains the above recommendation policy on the ACP edge node. This explains the above recommendation
to use ACP ULA prefix covered prefixes for ACP connect interfaces: to use ACP ULA prefix covered prefixes for ACP connect interfaces:
They allow for a shorter list of prefixes to be signaled via RFC4191 They allow for a shorter list of prefixes to be signaled via RFC4191
to NMS hosts and software components. to NMS hosts and software components.
skipping to change at page 93, line 22 skipping to change at page 94, line 46
| | | [ACP ]. | . | |+ | | | [ACP ]. | . | |+
| | | .[VRF ] .[VRF ] | v | "ACP address"|| | | | .[VRF ] .[VRF ] | v | "ACP address"||
| +-------+. .[Select].+--------+ "Date Plane || | +-------+. .[Select].+--------+ "Date Plane ||
| | ^ | .[Data ]. | | Address(es)"|| | | ^ | .[Data ]. | | Address(es)"||
| | . | [Plane] | | || | | . | [Plane] | | ||
| | . | [ ] | +--------------+| | | . | [ ] | +--------------+|
+--------+ . +--------------------+ +--------------+ +--------+ . +--------------------+ +--------------+
. .
Data-Plane "native" and + ACP auto-negotiated/encrypted Data-Plane "native" and + ACP auto-negotiated/encrypted
Figure 16: VRF select Figure 17: VRF select
Using two physical and/or virtual subnets (and therefore interfaces) Using two physical and/or virtual subnets (and therefore interfaces)
into NMS Hosts (as per Section 8.1.1) or Software (as per into NMS Hosts (as per Section 8.1.1) or Software (as per
Section 8.1.2) may be seen as additional complexity, for example with Section 8.1.2) may be seen as additional complexity, for example with
legacy NMS Hosts that support only one IP interface. legacy NMS Hosts that support only one IP interface, or it may be
insufficient to support [RFC4191] Type A or B host (see
Section 8.1.3).
To provide a single subnet into both ACP and Data-Plane, the ACP Edge To provide a single subnet into both ACP and Data-Plane, the ACP Edge
node needs to de-multiplex packets from NMS hosts into ACP VRF and node needs to de-multiplex packets from NMS hosts into ACP VRF and
Data-Plane. This is sometimes called "VRF select". If the ACP VRF Data-Plane. This is sometimes called "VRF select". If the ACP VRF
has no overlapping IPv6 addresses with the Data-Plane (it should have has no overlapping IPv6 addresses with the Data-Plane (it should have
no overlapping addresses), then this function can use the IPv6 no overlapping addresses), then this function can use the IPv6
Destination address. The problem is Source Address Selection on the Destination address. The problem is Source Address Selection on the
NMS Host(s) according to RFC6724. NMS Host(s) according to RFC6724.
Consider the simple case: The ACP uses only one ULA prefix, the ACP Consider the simple case: The ACP uses only one ULA prefix, the ACP
skipping to change at page 95, line 48 skipping to change at page 97, line 29
ABNF. ABNF.
connection = [ method , local-addr, remote-addr, ?pmtu ] connection = [ method , local-addr, remote-addr, ?pmtu ]
method = [ "IKEv2" , ?port ] method = [ "IKEv2" , ?port ]
method =/ [ "DTLS", port ] method =/ [ "DTLS", port ]
local-addr = [ address , ?vrf ] local-addr = [ address , ?vrf ]
remote-addr = [ address ] remote-addr = [ address ]
address = ("any" | ipv4-address | ipv6-address ) address = ("any" | ipv4-address | ipv6-address )
vrf = tstr ; Name of a VRF on this node with local-address vrf = tstr ; Name of a VRF on this node with local-address
Figure 17: Parameters for remote ACP neighbors Figure 18: Parameters for remote ACP neighbors
Explicit configuration of a remote-peer according to this ABNF Explicit configuration of a remote-peer according to this ABNF
provides all the information to build a secure channel without provides all the information to build a secure channel without
requiring a tunnel to that peer and running DULL GRASP inside of it. requiring a tunnel to that peer and running DULL GRASP inside of it.
The configuration includes the parameters otherwise signaled via DULL The configuration includes the parameters otherwise signaled via DULL
GRASP: local address, remote (peer) locator and method. The GRASP: local address, remote (peer) locator and method. The
differences over DULL GRASP local neighbor discovery and secure differences over DULL GRASP local neighbor discovery and secure
channel creation are as follows: channel creation are as follows:
o The local and remote address can be IPv4 or IPv6 and are typically * The local and remote address can be IPv4 or IPv6 and are typically
global scope addresses. global scope addresses.
* The VRF across which the connection is built (and in which local-
o The VRF across which the connection is built (and in which local-
addr exists) can to be specified. If vrf is not specified, it is addr exists) can to be specified. If vrf is not specified, it is
the default VRF on the node. In DULL GRASP the VRF is implied by the default VRF on the node. In DULL GRASP the VRF is implied by
the interface across which DULL GRASP operates. the interface across which DULL GRASP operates.
* If local address is "any", the local address used when initiating
o If local address is "any", the local address used when initiating
a secure channel connection is decided by source address selection a secure channel connection is decided by source address selection
([RFC6724] for IPv6). As a responder, the connection listens on ([RFC6724] for IPv6). As a responder, the connection listens on
all addresses of the node in the selected VRF. all addresses of the node in the selected VRF.
* Configuration of port is only required for methods where no
o Configuration of port is only required for methods where no
defaults exist (e.g., "DTLS"). defaults exist (e.g., "DTLS").
o If remote address is "any", the connection is only a responder. * If remote address is "any", the connection is only a responder.
It is a "hub" that can be used by multiple remote peers to connect It is a "hub" that can be used by multiple remote peers to connect
simultaneously - without having to know or configure their simultaneously - without having to know or configure their
addresses. Example: Hub site for remote "spoke" sites reachable addresses. Example: Hub site for remote "spoke" sites reachable
over the Internet. over the Internet.
* Pmtu should be configurable to overcome issues/limitations of Path
o Pmtu should be configurable to overcome issues/limitations of Path
MTU Discovery (PMTUD). MTU Discovery (PMTUD).
* IKEv2/IPsec to remote peers should support the optional NAT
o IKEv2/IPsec to remote peers should support the optional NAT
Traversal (NAT-T) procedures. Traversal (NAT-T) procedures.
8.2.2. Tunneled Remote ACP Neighbor 8.2.2. Tunneled Remote ACP Neighbor
An IPinIP, GRE or other form of pre-existing tunnel is configured An IPinIP, GRE or other form of pre-existing tunnel is configured
between two remote ACP peers and the virtual interfaces representing between two remote ACP peers and the virtual interfaces representing
the tunnel are configured for "ACP enable". This will enable IPv6 the tunnel are configured for "ACP enable". This will enable IPv6
link local addresses and DULL on this tunnel. In result, the tunnel link local addresses and DULL on this tunnel. In result, the tunnel
is used for normal "L2 adjacent" candidate ACP neighbor discovery is used for normal "L2 adjacent" candidate ACP neighbor discovery
with DULL and secure channel setup procedures described in this with DULL and secure channel setup procedures described in this
skipping to change at page 97, line 9 skipping to change at page 98, line 35
Tunneled Remote ACP Neighbor requires two encapsulations: the Tunneled Remote ACP Neighbor requires two encapsulations: the
configured tunnel and the secure channel inside of that tunnel. This configured tunnel and the secure channel inside of that tunnel. This
makes it in general less desirable than Configured Remote ACP makes it in general less desirable than Configured Remote ACP
Neighbor. Benefits of tunnels are that it may be easier to implement Neighbor. Benefits of tunnels are that it may be easier to implement
because there is no change to the ACP functionality - just running it because there is no change to the ACP functionality - just running it
over a virtual (tunnel) interface instead of only native interfaces. over a virtual (tunnel) interface instead of only native interfaces.
The tunnel itself may also provide PMTUD while the secure channel The tunnel itself may also provide PMTUD while the secure channel
method may not. Or the tunnel mechanism is permitted/possible method may not. Or the tunnel mechanism is permitted/possible
through some firewall while the secure channel method may not. through some firewall while the secure channel method may not.
Tunneling using an insecure tunnel encapsulation increases on average
the risk of a MITM downgrade attack somewhere along the underlay path
that blocks all but the most easily attacked ACP secure channel
option. ACP nodes supporting tunneled remote ACP Neighbors SHOULD
support configuration on such tunnel interfaces to restrict or
explicitly select the available ACP secure channel protocols (if the
ACP node supports more than one ACP secure channel protocol in the
first place).
8.2.3. Summary 8.2.3. Summary
Configured/Tunneled Remote ACP neighbors are less "indestructible" Configured/Tunneled Remote ACP neighbors are less "indestructible"
than L2 adjacent ACP neighbors based on link local addressing, since than L2 adjacent ACP neighbors based on link local addressing, since
they depend on more correct Data-Plane operations, such as routing they depend on more correct Data-Plane operations, such as routing
and global addressing. and global addressing.
Nevertheless, these options may be crucial to incrementally deploy Nevertheless, these options may be crucial to incrementally deploy
the ACP, especially if it is meant to connect islands across the the ACP, especially if it is meant to connect islands across the
Internet. Implementations SHOULD support at least Tunneled Remote Internet. Implementations SHOULD support at least Tunneled Remote
skipping to change at page 97, line 31 skipping to change at page 99, line 20
9. ACP Operations (Informative) 9. ACP Operations (Informative)
The following sections document important operational aspects of the The following sections document important operational aspects of the
ACP. They are not normative because they do not impact the ACP. They are not normative because they do not impact the
interoperability between components of the ACP, but they include interoperability between components of the ACP, but they include
recommendations/requirements for the internal operational model recommendations/requirements for the internal operational model
beneficial or necessary to achieve the desired use-case benefits of beneficial or necessary to achieve the desired use-case benefits of
the ACP (see Section 3). the ACP (see Section 3).
o Section 9.1 describes recommended operator diagnostics * Section 9.1 describes recommended operator diagnostics
capabilities of ACP nodes. capabilities of ACP nodes.
* Section 9.2 describes high level how an ACP registrar needs to
o Section 9.2 describes high level how an ACP registrar needs to
work, what its configuration parameters are and specific issues work, what its configuration parameters are and specific issues
impacting the choices of deployment design due to renewal and impacting the choices of deployment design due to renewal and
revocation issues. It describes a model where ACP Registrars have revocation issues. It describes a model where ACP Registrars have
their own sub-CA to provide the most distributed deployment option their own sub-CA to provide the most distributed deployment option
for ACP Registrars, and it describes considerations for for ACP Registrars, and it describes considerations for
centralized policy control of ACP Registrar operations. centralized policy control of ACP Registrar operations.
* Section 9.3 describes suggested ACP node behavior and operational
o Section 9.3 describes suggested ACP node behavior and operational
interfaces (configuration options) to manage the ACP in so-called interfaces (configuration options) to manage the ACP in so-called
greenfield devices (previously unconfigured) and brownfield greenfield devices (previously unconfigured) and brownfield
devices (preconfigured). devices (preconfigured).
The recommendations and suggestions of this chapter were derived from The recommendations and suggestions of this chapter were derived from
operational experience gained with a commercially available pre- operational experience gained with a commercially available pre-
standard ACP implementation. standard ACP implementation.
9.1. ACP (and BRSKI) Diagnostics 9.1. ACP (and BRSKI) Diagnostics
skipping to change at page 98, line 33 skipping to change at page 100, line 21
operators are expected to ask, such as "is the ACP working operators are expected to ask, such as "is the ACP working
correctly?", or "why is there no ACP connection to a known correctly?", or "why is there no ACP connection to a known
neighboring node?" neighboring node?"
In current network management approaches, the logic to answer these In current network management approaches, the logic to answer these
questions is most often built as centralized diagnostics software questions is most often built as centralized diagnostics software
that leverages the above mentioned data models. While this approach that leverages the above mentioned data models. While this approach
is feasible for components utilizing the ANI, it is not sufficient to is feasible for components utilizing the ANI, it is not sufficient to
diagnose the ANI itself: diagnose the ANI itself:
o Developing the logic to identify common issues requires * Developing the logic to identify common issues requires
operational experience with the components of the ANI. Letting operational experience with the components of the ANI. Letting
each management system define its own analysis is inefficient. each management system define its own analysis is inefficient.
* When the ANI is not operating correctly, it may not be possible to
o When the ANI is not operating correctly, it may not be possible to
run diagnostics from remote because of missing connectivity. The run diagnostics from remote because of missing connectivity. The
ANI should therefore have diagnostic capabilities available ANI should therefore have diagnostic capabilities available
locally on the nodes themselves. locally on the nodes themselves.
* Certain operations are difficult or impossible to monitor in real-
o Certain operations are difficult or impossible to monitor in real-
time, such as initial bootstrap issues in a network location where time, such as initial bootstrap issues in a network location where
no capabilities exist to attach local diagnostics. Therefore it no capabilities exist to attach local diagnostics. Therefore it
is important to also define means of capturing (logging) is important to also define means of capturing (logging)
diagnostics locally for later retrieval. Ideally, these captures diagnostics locally for later retrieval. Ideally, these captures
are also non-volatile so that they can survive extended power-off are also non-volatile so that they can survive extended power-off
conditions - for example when a device that fails to be brought up conditions - for example when a device that fails to be brought up
zero-touch is being sent back for diagnostics at a more zero-touch is being sent back for diagnostics at a more
appropriate location. appropriate location.
The most simple form of diagnostics answering questions such as the The most simple form of diagnostics answering questions such as the
above is to represent the relevant information sequentially in above is to represent the relevant information sequentially in
dependency order, so that the first non-expected/non-operational item dependency order, so that the first non-expected/non-operational item
is the most likely root cause. Or just log/highlight that item. For is the most likely root cause. Or just log/highlight that item. For
example: example:
Q: Is ACP operational to accept neighbor connections: Q: Is ACP operational to accept neighbor connections:
o Check if any potentially necessary configuration to make ACP/ANI * Check if any potentially necessary configuration to make ACP/ANI
operational are correct (see Section 9.3 for a discussion of such operational are correct (see Section 9.3 for a discussion of such
commands). commands).
* Does the system time look reasonable, or could it be the default
o Does the system time look reasonable, or could it be the default
system time after clock chip battery failure (certificate checks system time after clock chip battery failure (certificate checks
depend on reasonable notion of time). depend on reasonable notion of time).
o Does the node have keying material - domain certificate, TA * Does the node have keying material - domain certificate, TA
certificates, .... certificates, ....
* If no keying material and ANI is supported/enabled, check the
o If no keying material and ANI is supported/enabled, check the
state of BRSKI (not detailed in this example). state of BRSKI (not detailed in this example).
* Check the validity of the domain certificate:
o Check the validity of the domain certificate: - Does the certificate validate against the TA?
- Has it been revoked?
* Does the certificate validate against the TA? - Was the last scheduled attempt to retrieve a CRL successful
* Has it been revoked?
* Was the last scheduled attempt to retrieve a CRL successful
(e.g., do we know that our CRL information is up to date). (e.g., do we know that our CRL information is up to date).
- Is the certificate valid: validity start time in the past,
* Is the certificate valid: validity start time in the past,
expiration time in the future? expiration time in the future?
- Does the certificate have a correctly formatted acp-node-name
* Does the certificate have a correctly formatted acp-node-name
field? field?
* Was the ACP VRF successfully created?
o Was the ACP VRF successfully created? * Is ACP enabled on one or more interfaces that are up and running?
o Is ACP enabled on one or more interfaces that are up and running?
If all this looks good, the ACP should be running locally "fine" - If all this looks good, the ACP should be running locally "fine" -
but we did not check any ACP neighbor relationships. but we did not check any ACP neighbor relationships.
Question: why does the node not create a working ACP connection to a Question: why does the node not create a working ACP connection to a
neighbor on an interface? neighbor on an interface?
o Is the interface physically up? Does it have an IPv6 link-local
address?
o Is it enabled for ACP? * Is the interface physically up? Does it have an IPv6 link-local
address?
o Do we successfully send DULL GRASP messages to the interface (link * Is it enabled for ACP?
* Do we successfully send DULL GRASP messages to the interface (link
layer errors)? layer errors)?
* Do we receive DULL GRASP messages on the interface? If not, some
o Do we receive DULL GRASP messages on the interface? If not, some
intervening L2 equipment performing bad MLD snooping could have intervening L2 equipment performing bad MLD snooping could have
caused problems. Provide e.g., diagnostics of the MLD querier caused problems. Provide e.g., diagnostics of the MLD querier
IPv6 and MAC address. IPv6 and MAC address.
* Do we see the ACP objective in any DULL GRASP message from that
o Do we see the ACP objective in any DULL GRASP message from that
interface? Diagnose the supported secure channel methods. interface? Diagnose the supported secure channel methods.
* Do we know the MAC address of the neighbor with the ACP objective?
o Do we know the MAC address of the neighbor with the ACP objective?
If not, diagnose SLAAC/ND state. If not, diagnose SLAAC/ND state.
* When did we last attempt to build an ACP secure channel to the
o When did we last attempt to build an ACP secure channel to the
neighbor? neighbor?
* If it failed, why:
o If it failed, why: - Did the neighbor close the connection on us or did we close the
* Did the neighbor close the connection on us or did we close the
connection on it because the domain certificate membership connection on it because the domain certificate membership
failed? failed?
- If the neighbor closed the connection on us, provide any error
* If the neighbor closed the connection on us, provide any error
diagnostics from the secure channel protocol. diagnostics from the secure channel protocol.
- If we failed the attempt, display our local reason:
* If we failed the attempt, display our local reason: o There was no common secure channel protocol supported by the
+ There was no common secure channel protocol supported by the
two neighbors (this could not happen on nodes supporting two neighbors (this could not happen on nodes supporting
this specification because it mandates common support for this specification because it mandates common support for
IPsec). IPsec).
+ The ACP certificate membership check (Section 6.1.3) fails: o The ACP certificate membership check (Section 6.2.3) fails:
+ The neighbor's certificate is not signed directly or
- The neighbor's certificate is not signed directly or
indirectly by one of the nodes TA. Provide diagnostics indirectly by one of the nodes TA. Provide diagnostics
which TA it has (can identify whom the device belongs which TA it has (can identify whom the device belongs
to). to).
+ The neighbor's certificate does not have the same domain
- The neighbor's certificate does not have the same domain
(or no domain at all). Diagnose domain-name and (or no domain at all). Diagnose domain-name and
potentially other cert info. potentially other cert info.
+ The neighbor's certificate has been revoked or could not
- The neighbor's certificate has been revoked or could not
be authenticated by OCSP. be authenticated by OCSP.
+ The neighbor's certificate has expired - or is not yet
- The neighbor's certificate has expired - or is not yet
valid. valid.
- Any other connection issues in e.g., IKEv2 / IPsec, DTLS?.
* Any other connection issues in e.g., IKEv2 / IPsec, DTLS?.
Question: Is the ACP operating correctly across its secure channels? Question: Is the ACP operating correctly across its secure channels?
o Are there one or more active ACP neighbors with secure channels? * Are there one or more active ACP neighbors with secure channels?
* Is the RPL routing protocol for the ACP running?
o Is the RPL routing protocol for the ACP running? * Is there a default route to the root in the ACP routing table?
* Is there for each direct ACP neighbor not reachable over the ACP
o Is there a default route to the root in the ACP routing table?
o Is there for each direct ACP neighbor not reachable over the ACP
virtual interface to the root a route in the ACP routing table? virtual interface to the root a route in the ACP routing table?
* Is ACP GRASP running?
o Is ACP GRASP running? * Is at least one SRV.est objective cached (to support certificate
o Is at least one SRV.est objective cached (to support certificate
renewal)? renewal)?
* Is there at least one BRSKI registrar objective cached (in case
o Is there at least one BRSKI registrar objective cached (in case
BRSKI is supported) BRSKI is supported)
* Is BRSKI proxy operating normally on all interfaces where ACP is
o Is BRSKI proxy operating normally on all interfaces where ACP is
operating? operating?
* ...
o ...
These lists are not necessarily complete, but illustrate the These lists are not necessarily complete, but illustrate the
principle and show that there are variety of issues ranging from principle and show that there are variety of issues ranging from
normal operational causes (a neighbor in another ACP domain) over normal operational causes (a neighbor in another ACP domain) over
problems in the credentials management (certificate lifetimes), problems in the credentials management (certificate lifetimes),
explicit security actions (revocation) or unexpected connectivity explicit security actions (revocation) or unexpected connectivity
issues (intervening L2 equipment). issues (intervening L2 equipment).
The items so far are illustrating how the ANI operations can be The items so far are illustrating how the ANI operations can be
diagnosed with passive observation of the operational state of its diagnosed with passive observation of the operational state of its
skipping to change at page 102, line 32 skipping to change at page 103, line 31
unsolicited (as it would be in LLDP) so that other observers on the unsolicited (as it would be in LLDP) so that other observers on the
same subnet can determine who is an "interested adjacent party". same subnet can determine who is an "interested adjacent party".
9.1.1. Secure Channel Peer diagnostics 9.1.1. Secure Channel Peer diagnostics
When using mutual certificate authentication, the TA certificate is When using mutual certificate authentication, the TA certificate is
not required to be signalled explicitly because its hash is not required to be signalled explicitly because its hash is
sufficient for certificate chain validation. In the case of ACP sufficient for certificate chain validation. In the case of ACP
secure channel setup this leads to limited diagnostics when secure channel setup this leads to limited diagnostics when
authentication fails because of TA mismatch. For this reason, authentication fails because of TA mismatch. For this reason,
Section 6.7.2 recommends to also include the TA certificate in the Section 6.8.2 recommends to also include the TA certificate in the
secure channel signalling. This should be possible to do without secure channel signalling. This should be possible to do without
protocol modifications in the security association protocols used by protocol modifications in the security association protocols used by
the ACP. For example, while [RFC7296] does not mention this, it also the ACP. For example, while [RFC7296] does not mention this, it also
does not prohibit it. does not prohibit it.
One common deployment use case where the diagnostic through the One common deployment use case where the diagnostic through the
signalled TA of a candidate peer is very helpfull are multi-tenant signalled TA of a candidate peer is very helpfull are multi-tenant
environments such as office buildings, where different tenants run environments such as office buildings, where different tenants run
their own networks and ACPs. Each tenant is given supposedly their own networks and ACPs. Each tenant is given supposedly
disjoint L2 connectivity through the building infrastructure. In disjoint L2 connectivity through the building infrastructure. In
skipping to change at page 103, line 7 skipping to change at page 104, line 7
While the ACP itself is not impact by this, the Data-Plane to be While the ACP itself is not impact by this, the Data-Plane to be
built later may be impacted. Therefore it is important to be able to built later may be impacted. Therefore it is important to be able to
diagnose such undesirable connectivity from the ACP so that any diagnose such undesirable connectivity from the ACP so that any
autonomic or non-autonomic mechanisms to configure the Data-Plane can autonomic or non-autonomic mechanisms to configure the Data-Plane can
accordingly treat such interfaces. The information in the TA of the accordingly treat such interfaces. The information in the TA of the
peer can then ease troubleshooting of such issues. peer can then ease troubleshooting of such issues.
Another example case is the intended or accidental re-activation of Another example case is the intended or accidental re-activation of
equipment whose TA certificate has long expired, such as redundant equipment whose TA certificate has long expired, such as redundant
gear taken from storage after years. Potentially without following gear taken from storage after years.
the correct process set up for such cases.
A third example case is when in a mergers&aquisition case ACP nodes A third example case is when in a mergers&aquisition case ACP nodes
have not been correctly provisioned with the mutual TA of previously have not been correctly provisioned with the mutual TA of previously
disjoint ACP. This is assuming that the ACP domain names where disjoint ACP. This is assuming that the ACP domain names where
already aligned so that the ACP domain membership check is only already aligned so that the ACP domain membership check is only
failing on the TA. failing on the TA.
A fourth example case is when multiple registrars where set up for A fourth example case is when multiple registrars where set up for
the same ACP but without correctly setting up the same TA. For the same ACP but without correctly setting up the same TA. For
example when registrars support to also be CA themselves but are example when registrars support to also be CA themselves but are
misconfigured to become TA instead of intermediate CA. misconfigured to become TA instead of intermediate CA.
9.2. ACP Registrars 9.2. ACP Registrars
As described in Section 6.10.7, the ACP addressing mechanism is As described in Section 6.11.7, the ACP addressing mechanism is
designed to enable lightweight, distributed and uncoordinated ACP designed to enable lightweight, distributed and uncoordinated ACP
registrars that are providing ACP address prefixes to candidate ACP registrars that are providing ACP address prefixes to candidate ACP
nodes by enrolling them with an ACP certificate into an ACP domain nodes by enrolling them with an ACP certificate into an ACP domain
via any appropriate mechanism/protocol, automated or not. via any appropriate mechanism/protocol, automated or not.
This section discusses informatively more details and options for ACP This section discusses informatively more details and options for ACP
registrars. registrars.
9.2.1. Registrar interactions 9.2.1. Registrar interactions
skipping to change at page 103, line 48 skipping to change at page 104, line 47
beside a TA is required. Typically, this is a root CA. One or more beside a TA is required. Typically, this is a root CA. One or more
uncoordinated acting ACP registrar can be set up, performing the uncoordinated acting ACP registrar can be set up, performing the
following interactions: following interactions:
To orchestrate enrolling a candidate ACP node autonomically, the ACP To orchestrate enrolling a candidate ACP node autonomically, the ACP
registrar can rely on the ACP and use Proxies to reach the candidate registrar can rely on the ACP and use Proxies to reach the candidate
ACP node, therefore allowing minimum pre-existing (auto-)configured ACP node, therefore allowing minimum pre-existing (auto-)configured
network services on the candidate ACP node. BRSKI defines the BRSKI network services on the candidate ACP node. BRSKI defines the BRSKI
proxy, a design that can be adopted for various protocols that proxy, a design that can be adopted for various protocols that
Pledges/candidate ACP nodes could want to use, for example BRSKI over Pledges/candidate ACP nodes could want to use, for example BRSKI over
CoAP (Constrained Application Protocol), or proxying of Netconf. CoAP (Constrained Application Protocol), or proxying of NETCONF.
To reach a TA that has no ACP connectivity, the ACP registrar would To reach a TA that has no ACP connectivity, the ACP registrar would
use the Data-Plane. ACP and Data-Plane in an ACP registrar could use the Data-Plane. ACP and Data-Plane in an ACP registrar could
(and by default should be) completely isolated from each other at the (and by default should be) completely isolated from each other at the
network level. Only applications such as the ACP registrar would network level. Only applications such as the ACP registrar would
need the ability for their transport stacks to access both. need the ability for their transport stacks to access both.
In non-autonomic enrollment options, the Data-Plane between a ACP In non-autonomic enrollment options, the Data-Plane between a ACP
registrar and the candidate ACP node needs to be configured first. registrar and the candidate ACP node needs to be configured first.
This includes the ACP registrar and the candidate ACP node. Then any This includes the ACP registrar and the candidate ACP node. Then any
appropriate set of protocols can be used between ACP registrar and appropriate set of protocols can be used between ACP registrar and