draft-ietf-6lo-rfc6775-update-12.txt   draft-ietf-6lo-rfc6775-update-13.txt 
6lo P. Thubert, Ed. 6lo P. Thubert, Ed.
Internet-Draft cisco Internet-Draft cisco
Updates: 6775 (if approved) E. Nordmark Updates: 6775 (if approved) E. Nordmark
Intended status: Standards Track Zededa Intended status: Standards Track Zededa
Expires: August 24, 2018 S. Chakrabarti Expires: August 26, 2018 S. Chakrabarti
Verizon Verizon
C. Perkins C. Perkins
Futurewei Futurewei
February 20, 2018 February 22, 2018
An Update to 6LoWPAN ND An Update to 6LoWPAN ND
draft-ietf-6lo-rfc6775-update-12 draft-ietf-6lo-rfc6775-update-13
Abstract Abstract
This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
clarify the role of the protocol as a registration technique, clarify the role of the protocol as a registration technique,
simplify the registration operation in 6LoWPAN routers, as well as to simplify the registration operation in 6LoWPAN routers, as well as to
provide enhancements to the registration capabilities and mobility provide enhancements to the registration capabilities and mobility
detection for different network topologies including the backbone detection for different network topologies including the backbone
routers performing proxy Neighbor Discovery in a low power network. routers performing proxy Neighbor Discovery in a low power network.
skipping to change at page 1, line 40 skipping to change at page 1, line 40
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 August 24, 2018. This Internet-Draft will expire on August 26, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Internet-Draft An Update to 6LoWPAN ND February
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Applicability of Address Registration Options . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Applicability of Address Registration Options . . . . . . . . 5
4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 6 4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Extended Address Registration Option (EARO) . . . . . . . 7 4.1. Extended Address Registration Option (EARO) . . . . . . . 7
4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 7 4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 7
4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 8 4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 7
4.3. Registration Unique ID . . . . . . . . . . . . . . . . . 9 4.3. Registration Unique ID . . . . . . . . . . . . . . . . . 9
4.4. Extended Duplicate Address Messages . . . . . . . . . . . 10 4.4. Extended Duplicate Address Messages . . . . . . . . . . . 10
4.5. Registering the Target Address . . . . . . . . . . . . . 10 4.5. Registering the Target Address . . . . . . . . . . . . . 10
4.6. Link-Local Addresses and Registration . . . . . . . . . . 11 4.6. Link-Local Addresses and Registration . . . . . . . . . . 11
4.7. Maintaining the Registration States . . . . . . . . . . . 12 4.7. Maintaining the Registration States . . . . . . . . . . . 12
5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 14 5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 14
6. Extended ND Options And Messages . . . . . . . . . . . . . . 14 6. Extended ND Options And Messages . . . . . . . . . . . . . . 14
6.1. Enhanced Address Registration Option (EARO) . . . . . . . 14 6.1. Enhanced Address Registration Option (EARO) . . . . . . . 14
6.2. Extended Duplicate Address Message Formats . . . . . . . 17 6.2. Extended Duplicate Address Message Formats . . . . . . . 16
6.3. New 6LoWPAN Capability Bits in the Capability Indication 6.3. New 6LoWPAN Capability Bits in the Capability Indication
Option . . . . . . . . . . . . . . . . . . . . . . . . . 18 Option . . . . . . . . . . . . . . . . . . . . . . . . . 17
7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 19 7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 18
7.1. Discovering the capabilities of an ND peer . . . . . . . 19 7.1. Discovering the capabilities of an ND peer . . . . . . . 18
7.1.1. Using the "E" Flag in the 6CIO . . . . . . . . . . . 19 7.1.1. Using the "E" Flag in the 6CIO . . . . . . . . . . . 18
7.1.2. Using the "T" Flag in the EARO . . . . . . . . . . . 19 7.1.2. Using the "T" Flag in the EARO . . . . . . . . . . . 18
7.2. Legacy 6LoWPAN Node . . . . . . . . . . . . . . . . . . . 20 7.2. RFC6775-only 6LoWPAN Node . . . . . . . . . . . . . . . . 19
7.3. Legacy 6LoWPAN Router . . . . . . . . . . . . . . . . . . 20 7.3. RFC6775-only 6LoWPAN Router . . . . . . . . . . . . . . . 19
7.4. Legacy 6LoWPAN Border Router . . . . . . . . . . . . . . 21 7.4. RFC6775-only 6LoWPAN Border Router . . . . . . . . . . . 20
8. Security Considerations . . . . . . . . . . . . . . . . . . . 21 8. Security Considerations . . . . . . . . . . . . . . . . . . . 20
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 23 9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 22
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 24 10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 23
10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 24 10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 23
10.3. New ARO Status values . . . . . . . . . . . . . . . . . 25 10.3. New ARO Status values . . . . . . . . . . . . . . . . . 24
10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 26 10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 24
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
12.1. Normative References . . . . . . . . . . . . . . . . . . 27 12.1. Normative References . . . . . . . . . . . . . . . . . . 25
12.2. Informative References . . . . . . . . . . . . . . . . . 28 12.2. Informative References . . . . . . . . . . . . . . . . . 26
12.3. External Informative References . . . . . . . . . . . . 31 12.3. External Informative References . . . . . . . . . . . . 30
Appendix A. Applicability and Requirements Served . . . . . . . 32 Appendix A. Applicability and Requirements Served . . . . . . . 30
Appendix B. Requirements . . . . . . . . . . . . . . . . . . . . 33 Appendix B. Requirements . . . . . . . . . . . . . . . . . . . . 31
B.1. Requirements Related to Mobility . . . . . . . . . . . . 31
Internet-Draft An Update to 6LoWPAN ND February B.2. Requirements Related to Routing Protocols . . . . . . . . 32
B.1. Requirements Related to Mobility . . . . . . . . . . . . 33
B.2. Requirements Related to Routing Protocols . . . . . . . . 33
B.3. Requirements Related to the Variety of Low-Power Link B.3. Requirements Related to the Variety of Low-Power Link
types . . . . . . . . . . . . . . . . . . . . . . . . . . 34 types . . . . . . . . . . . . . . . . . . . . . . . . . . 33
B.4. Requirements Related to Proxy Operations . . . . . . . . 35 B.4. Requirements Related to Proxy Operations . . . . . . . . 34
B.5. Requirements Related to Security . . . . . . . . . . . . 35 B.5. Requirements Related to Security . . . . . . . . . . . . 34
B.6. Requirements Related to Scalability . . . . . . . . . . . 37 B.6. Requirements Related to Scalability . . . . . . . . . . . 35
B.7. Matching Requirements with Specifications . . . . . . . . 37 B.7. Requirements Related to Operations and Management . . . . 36
B.8. Matching Requirements with Specifications . . . . . . . . 36
Appendix C. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . 38 Appendix C. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction 1. Introduction
The scope of this draft is an IPv6 Low Power Networks including star The scope of this draft is an IPv6 Low Power Networks including star
and mesh topologies. This specification modifies and extends the and mesh topologies. This specification modifies and extends the
behavior and protocol elements of "Neighbor Discovery Optimization behavior and protocol elements of "Neighbor Discovery Optimization
for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND) for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND)
[RFC6775] to enable additional capabilities and enhancements such as: [RFC6775] to enable additional capabilities and enhancements such as:
o Support for indicating mobility vs retry (T-bit) o Support for indicating mobility vs retry (T-bit)
skipping to change at page 3, line 27 skipping to change at page 3, line 25
1. Introduction 1. Introduction
The scope of this draft is an IPv6 Low Power Networks including star The scope of this draft is an IPv6 Low Power Networks including star
and mesh topologies. This specification modifies and extends the and mesh topologies. This specification modifies and extends the
behavior and protocol elements of "Neighbor Discovery Optimization behavior and protocol elements of "Neighbor Discovery Optimization
for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND) for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND)
[RFC6775] to enable additional capabilities and enhancements such as: [RFC6775] to enable additional capabilities and enhancements such as:
o Support for indicating mobility vs retry (T-bit) o Support for indicating mobility vs retry (T-bit)
o Simplify the registration flow for link-local addresses o Simplify the registration flow for link-local addresses
o Enhancement to Address Registration Option (ARO) o Enhancement to Address Registration Option (ARO)
o Permitting registration of a target address o Permitting registration of a target address
o Clarification of support of privacy and temporary addresses o Clarification of support of privacy and temporary addresses
The applicability of 6LoWPAN ND registration is discussed in The applicability of 6LoWPAN ND registration is discussed in
Section 2, and new extensions and updates to [RFC6775] are presented Section 3, and new extensions and updates to [RFC6775] are presented
in Section 4. Considerations on Backward Compatibility, Security and in Section 4. Considerations on Backward Compatibility, Security and
Privacy are also elaborated upon in Section 7, Section 8 and in Privacy are also elaborated upon in Section 7, Section 8 and in
Section 9, respectively. Section 9, respectively.
2. Applicability of Address Registration Options 2. Terminology
The purpose of the Address Registration Option (ARO) in the legacy
6LoWPAN ND specification is to facilitate duplicate address detection
(DAD) for hosts as well as populate Neighbor Cache Entries (NCE)
[RFC4861] in the routers. This reduces the reliance on multicast
operations, which are often as intrusive as broadcast, in IPv6 ND
operations.
With this specification, a failed or useless registration can be
detected for reasons other than address duplication. Examples
include: the router having run out of space; a registration bearing a
stale sequence number perhaps denoting a movement of the host after
Internet-Draft An Update to 6LoWPAN ND February
the registration was placed; a host misbehaving and attempting to
register an invalid address such as the unspecified address
[RFC4291]; or a host using an address which is not topologically
correct on that link.
In such cases the host will receive an error to help diagnose the
issue and may retry, possibly with a different address, and possibly
registering to a different router, depending on the returned error.
The ability to return errors to address registrations is not intended
to be used to restrict the ability of hosts to form and use multiple
addresses, as recommended in "Host Address Availability
Recommendations" [RFC7934].
In particular, the freedom to form and register addresses is needed
for enhanced privacy; each host may register a number of addresses
using mechanisms such as "Privacy Extensions for Stateless Address
Autoconfiguration (SLAAC) in IPv6" [RFC4941].
In IPv6 ND [RFC4861], a router must have enough storage to hold
neighbor cache entries for all the addresses to which it may forward.
A router using the Address Registration mechanism also needs enough
storage to hold NCEs for all the addresses that may be registered to
it, regardless of whether or not they are actively communicating.
The number of registrations supported by a 6LoWPAN Router (6LR) or
6LoWPAN Border Router (6LBR) must be clearly documented.
A network administrator should deploy updated 6LR/6LBRs to support
the number and type of devices in their network, based on the number
of IPv6 addresses that those devices require and their address
renewal rate and behavior.
3. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
The Terminology used in this document is consistent with and The Terminology used in this document is consistent with and
incorporates that described in Terms Used in Routing for Low-Power incorporates that described in Terms Used in Routing for Low-Power
and Lossy Networks (LLNs). [RFC7102]. and Lossy Networks (LLNs). [RFC7102].
Other terms in use in LLNs are found in Terminology for Constrained- Other terms in use in LLNs are found in Terminology for Constrained-
skipping to change at page 4, line 53 skipping to change at page 4, line 4
The Terminology used in this document is consistent with and The Terminology used in this document is consistent with and
incorporates that described in Terms Used in Routing for Low-Power incorporates that described in Terms Used in Routing for Low-Power
and Lossy Networks (LLNs). [RFC7102]. and Lossy Networks (LLNs). [RFC7102].
Other terms in use in LLNs are found in Terminology for Constrained- Other terms in use in LLNs are found in Terminology for Constrained-
Node Networks [RFC7228]. Node Networks [RFC7228].
Readers are expected to be familiar with all the terms and concepts Readers are expected to be familiar with all the terms and concepts
that are discussed in that are discussed in
o "Neighbor Discovery for IP version 6" [RFC4861], o "Neighbor Discovery for IP version 6" [RFC4861],
Internet-Draft An Update to 6LoWPAN ND February
o "IPv6 Stateless Address Autoconfiguration" [RFC4862], o "IPv6 Stateless Address Autoconfiguration" [RFC4862],
o "Problem Statement and Requirements for IPv6 over Low-Power o "Problem Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing" [RFC6606], Wireless Personal Area Network (6LoWPAN) Routing" [RFC6606],
o "IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs): o "IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals" [RFC4919], Overview, Assumptions, Problem Statement, and Goals" [RFC4919],
o "Neighbor Discovery Optimization for Low-power and Lossy Networks" o "Neighbor Discovery Optimization for Low-power and Lossy Networks"
[RFC6775] and [RFC6775] and
o "Multi-link Subnet Support in IPv6" o "Multi-link Subnet Support in IPv6"
[I-D.ietf-ipv6-multilink-subnets], [I-D.ietf-ipv6-multilink-subnets],
as well as the following terminology: as well as the following terminology:
Backbone Link: An IPv6 transit link that interconnects two or more Backbone Link: An IPv6 transit link that interconnects two or more
Backbone Routers. It is expected to be a higher speed device Backbone Routers. It is expected to be of high speed compared
speed compared to the LLN in order to carry the traffic that is to the LLN in order to carry the traffic that is required to
required to federate multiple segments of the potentially large federate multiple segments of the potentially large LLN into a
LLN into a single IPv6 subnet. single IPv6 subnet.
Backbone Router: A logical network function in an IPv6 router that Backbone Router: A logical network function in an IPv6 router that
federates a LLN over a Backbone Link. In order to do so, the federates a LLN over a Backbone Link. In order to do so, the
Backbone Router (6BBR) proxies the 6LoWPAN ND operations Backbone Router (6BBR) proxies the 6LoWPAN ND operations
detailed in the document onto the matching operations that run detailed in the document onto the matching operations that run
over the backbone, typically IPv6 ND. Note that 6BBR is a over the backbone, typically IPv6 ND. Note that 6BBR is a
logical function, just like 6LR and 6LBR, and that a same logical function, just like 6LR and 6LBR, and that a same
physical router may operate all three. physical router may operate all three.
Extended LLN: The aggregation of multiple LLNs as defined in Extended LLN: The aggregation of multiple LLNs as defined in
[RFC4919], interconnected by a Backbone Link via Backbone [RFC4919], interconnected by a Backbone Link via Backbone
Routers, and forming a single IPv6 MultiLink Subnet. Routers, and forming a single IPv6 MultiLink Subnet.
Registration: The process during which a 6LN registers its Registration: The process during which a 6LN registers its
address(es) with the Border Router so the 6BBR can serve as address(es) with the Border Router so the 6BBR can serve as
proxy for ND operations over the Backbone. proxy for ND operations over the Backbone.
Binding: The association between an IP address with a MAC address, a Binding: The association between an IP address with a MAC address, a
port and/or other information about the node that owns the IP port and/or other information about the node that owns the IP
address. address.
Registered Node: The node for which the registration is performed, Registered Node: The node for which the registration is performed,
and which owns the fields in the EARO option. and which owns the fields in the EARO option.
Registering Node: The node that performs the registration to the Registering Node: The node that performs the registration to the
6BBR, which may proxy for the registered node. 6BBR, which may proxy for the registered node.
Internet-Draft An Update to 6LoWPAN ND February
Registered Address: An address owned by the Registered Node node Registered Address: An address owned by the Registered Node node
that was or is being registered. that was or is being registered.
RFC6775-only: Applied to a type of node or a type of message, this
adjective indicates a behavior that is strictly as specified by
[RFC6775] as opposed to updated with this specification.
updated: a 6LN, a 6LR or a 6LBR that supports this specification.
legacy: a 6LN, a 6LR or a 6LBR that supports [RFC6775] but not this 3. Applicability of Address Registration Options
specification.
updated: a 6LN, a 6LR or a 6LBR that supports this specification. The purpose of the Address Registration Option (ARO) in [RFC6775] is
to facilitate duplicate address detection (DAD) for hosts as well as
populate Neighbor Cache Entries (NCE) [RFC4861] in the routers. This
reduces the reliance on multicast operations, which are often as
intrusive as broadcast, in IPv6 ND operations.
With this specification, a failed or useless registration can be
detected by a 6LR or a 6LBR for reasons other than address
duplication. Examples include: the router having run out of space; a
registration bearing a stale sequence number perhaps denoting a
movement of the host after the registration was placed; a host
misbehaving and attempting to register an invalid address such as the
unspecified address [RFC4291]; or a host using an address which is
not topologically correct on that link.
In such cases the host will receive an error to help diagnose the
issue and may retry, possibly with a different address, and possibly
registering to a different router, depending on the returned error.
The ability to return errors to address registrations is not intended
to be used to restrict the ability of hosts to form and use multiple
addresses, as recommended in "Host Address Availability
Recommendations" [RFC7934].
In particular, the freedom to form and register addresses is needed
for enhanced privacy; each host may register a number of addresses
using mechanisms such as "Privacy Extensions for Stateless Address
Autoconfiguration (SLAAC) in IPv6" [RFC4941].
In IPv6 ND [RFC4861], a router must have enough storage to hold
neighbor cache entries for all the addresses to which it may forward.
A router using the Address Registration mechanism also needs enough
storage to hold NCEs for all the addresses that may be registered to
it, regardless of whether or not they are actively communicating.
The number of registrations supported by a 6LoWPAN Router (6LR) or
6LoWPAN Border Router (6LBR) must be clearly documented.
A network administrator should deploy updated 6LR/6LBRs to support
the number and type of devices in their network, based on the number
of IPv6 addresses that those devices require and their address
renewal rate and behavior.
4. Updating RFC 6775 4. Updating RFC 6775
This specification introduces the Extended Address Registration This specification introduces the Extended Address Registration
Option (EARO) based on the ARO as defined [RFC6775]; in particular a Option (EARO) based on the ARO as defined [RFC6775]; in particular a
"T" flag is added that MUST be set in NS messages when this "T" flag is added that MUST be set in NS messages when this
specification is used, and echoed in NA messages to confirm that the specification is used, and echoed in NA messages to confirm that the
protocol is supported. protocol is supported.
The extensions to the ARO option are used in the Duplicate Address The extensions to the ARO option are used in the Duplicate Address
Request (DAR) and Duplicate Address Confirmation (DAC) messages, so Request (DAR) and Duplicate Address Confirmation (DAC) messages, so
as to convey the additional information all the way to the 6LBR. In as to convey the additional information all the way to the 6LBR. In
turn the 6LBR may proxy the registration using IPv6 ND over a turn the 6LBR may proxy the registration using IPv6 ND over a
backbone as illustrated in Figure 1. Note that this specification Backbone Link as illustrated in Figure 1. Note that this
avoids the extended DAR flow for Link Local Addresses in a Route-Over specification avoids the extended DAR flow for Link Local Addresses
[RFC6606] mesh. in a Route-Over [RFC6606] mesh.
6LN 6LR 6LBR 6BBR 6LN 6LR 6LBR 6BBR
| | | | | | | |
| NS(EARO) | | | | NS(EARO) | | |
|--------------->| | | |--------------->| | |
| | Extended DAR | | | | Extended DAR | |
| |-------------->| | | |-------------->| |
| | | | | | | |
| | | proxy NS(EARO) | | | | proxy NS(EARO) |
| | |--------------->| | | |--------------->|
skipping to change at page 7, line 5 skipping to change at page 6, line 38
| | | proxy NA(EARO) | | | | proxy NA(EARO) |
| | |<---------------| | | |<---------------|
| | Extended DAC | | | | Extended DAC | |
| |<--------------| | | |<--------------| |
| NA(EARO) | | | | NA(EARO) | | |
|<---------------| | | |<---------------| | |
| | | | | | | |
Figure 1: (Re-)Registration Flow Figure 1: (Re-)Registration Flow
Internet-Draft An Update to 6LoWPAN ND February
In order to support various types of link layers, it is RECOMMENDED In order to support various types of link layers, it is RECOMMENDED
to allow multiple registrations, including for privacy / temporary to allow multiple registrations, including for privacy / temporary
addresses, and provide new mechanisms to help clean up stale addresses, and provide new mechanisms to help clean up stale
registration states as soon as possible. registration states as soon as possible.
Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface
and locates available 6LRs; a Registering Node SHOULD prefer and locates available 6LRs; a Registering Node SHOULD prefer
registering to a 6LR that is found to support this specification, as registering to a 6LR that is found to support this specification, as
discussed in Section 7.1, over a legacy one. discussed in Section 7.1, over a RFC6775-only one.
4.1. Extended Address Registration Option (EARO) 4.1. Extended Address Registration Option (EARO)
The Extended ARO (EARO) deprecates the ARO and is backward compatible The Extended ARO (EARO) deprecates the ARO and is backward compatible
with it. More details on backward compatibility can be found in with it. More details on backward compatibility can be found in
Section 7. Section 7.
The semantics of the ARO are modified as follows: The semantics of the ARO are modified as follows:
o The address that is being registered with a Neighbor Solicitation o The address that is being registered with a Neighbor Solicitation
skipping to change at page 8, line 5 skipping to change at page 7, line 40
4.2. Transaction ID 4.2. Transaction ID
The Transaction ID (TID) is a sequence number that is incremented The Transaction ID (TID) is a sequence number that is incremented
with each re-registration. The TID is used to detect the freshness with each re-registration. The TID is used to detect the freshness
of the registration request and useful to detect one single of the registration request and useful to detect one single
registration by multiple 6LoWPAN border routers (e.g., 6LBRs and registration by multiple 6LoWPAN border routers (e.g., 6LBRs and
6BBRs) supporting the same 6LoWPAN. The TID may also be used by the 6BBRs) supporting the same 6LoWPAN. The TID may also be used by the
network to track the sequence of movements of a node in order to network to track the sequence of movements of a node in order to
route to the current (freshest known) location of a moving node. route to the current (freshest known) location of a moving node.
Internet-Draft An Update to 6LoWPAN ND February
When a Registered Node is registered with multiple 6BBRs in parallel, When a Registered Node is registered with multiple 6BBRs in parallel,
the same TID SHOULD be used, to enable the 6BBRs to determine that the same TID SHOULD be used, to enable the 6BBRs to determine that
the registrations are the same, and distinguish that situation from a the registrations are the same, and distinguish that situation from a
movement. movement.
4.2.1. Comparing TID values 4.2.1. Comparing TID values
The TID is a sequence counter and its operation is the exact match of The TID is a sequence counter and its operation is the exact match of
the path sequence specified in RPL, the IPv6 Routing Protocol for the path sequence specified in RPL, the IPv6 Routing Protocol for
Low-Power and Lossy Networks [RFC6550] specification. Low-Power and Lossy Networks [RFC6550] specification.
skipping to change at page 8, line 43 skipping to change at page 8, line 30
detailed below. detailed below.
A window of comparison, SEQUENCE_WINDOW = 16, is configured based on A window of comparison, SEQUENCE_WINDOW = 16, is configured based on
a value of 2^N, where N is defined to be 4 in this specification. a value of 2^N, where N is defined to be 4 in this specification.
For a given sequence counter, For a given sequence counter,
1. The sequence counter SHOULD be initialized to an implementation 1. The sequence counter SHOULD be initialized to an implementation
defined value which is 128 or greater prior to use. A defined value which is 128 or greater prior to use. A
recommended value is 240 (256 - SEQUENCE_WINDOW). recommended value is 240 (256 - SEQUENCE_WINDOW).
2. When a sequence counter increment would cause the sequence 2. When a sequence counter increment would cause the sequence
counter to increment beyond its maximum value, the sequence counter to increment beyond its maximum value, the sequence
counter MUST wrap back to zero. When incrementing a sequence counter MUST wrap back to zero. When incrementing a sequence
counter greater than or equal to 128, the maximum value is 255. counter greater than or equal to 128, the maximum value is 255.
When incrementing a sequence counter less than 128, the maximum When incrementing a sequence counter less than 128, the maximum
value is 127. value is 127.
3. When comparing two sequence counters, the following rules MUST be 3. When comparing two sequence counters, the following rules MUST be
applied: applied:
Internet-Draft An Update to 6LoWPAN ND February
1. When a first sequence counter A is in the interval [128..255] 1. When a first sequence counter A is in the interval [128..255]
and a second sequence counter B is in [0..127]: and a second sequence counter B is in [0..127]:
1. If (256 + B - A) is less than or equal to 1. If (256 + B - A) is less than or equal to
SEQUENCE_WINDOW, then B is greater than A, A is less than SEQUENCE_WINDOW, then B is greater than A, A is less than
B, and the two are not equal. B, and the two are not equal.
2. If (256 + B - A) is greater than SEQUENCE_WINDOW, then A 2. If (256 + B - A) is greater than SEQUENCE_WINDOW, then A
is greater than B, B is less than A, and the two are not is greater than B, B is less than A, and the two are not
equal. equal.
For example, if A is 240, and B is 5, then (256 + 5 - 240) is For example, if A is 240, and B is 5, then (256 + 5 - 240) is
21. 21 is greater than SEQUENCE_WINDOW (16), thus 240 is 21. 21 is greater than SEQUENCE_WINDOW (16), thus 240 is
greater than 5. As another example, if A is 250 and B is 5, greater than 5. As another example, if A is 250 and B is 5,
then (256 + 5 - 250) is 11. 11 is less than SEQUENCE_WINDOW then (256 + 5 - 250) is 11. 11 is less than SEQUENCE_WINDOW
(16), thus 250 is less than 5. (16), thus 250 is less than 5.
2. In the case where both sequence counters to be compared are 2. In the case where both sequence counters to be compared are
less than or equal to 127, and in the case where both less than or equal to 127, and in the case where both
sequence counters to be compared are greater than or equal to sequence counters to be compared are greater than or equal to
128: 128:
1. If the absolute magnitude of difference between the two 1. If the absolute magnitude of difference between the two
sequence counters is less than or equal to sequence counters is less than or equal to
SEQUENCE_WINDOW, then a comparison as described in SEQUENCE_WINDOW, then a comparison as described in
[RFC1982] is used to determine the relationships greater [RFC1982] is used to determine the relationships greater
than, less than, and equal. than, less than, and equal.
skipping to change at page 9, line 51 skipping to change at page 9, line 31
the results of the comparison are not defined, then a node should the results of the comparison are not defined, then a node should
give precedence to the sequence number that was most recently give precedence to the sequence number that was most recently
incremented. Failing this, the node should select the sequence incremented. Failing this, the node should select the sequence
number in order to minimize the resulting changes to its own number in order to minimize the resulting changes to its own
state. state.
4.3. Registration Unique ID 4.3. Registration Unique ID
The Registration Unique ID (RUID) enables a duplicate address The Registration Unique ID (RUID) enables a duplicate address
registration to be distinguished from a double registration or a registration to be distinguished from a double registration or a
movement. An ND message from the 6BBR over the Backbone that is movement. An ND message from the 6BBR over the Backbone Link that is
proxied on behalf of a Registered Node must carry the most recent proxied on behalf of a Registered Node must carry the most recent
EARO option seen for that node. A NS/NA with an EARO and a NS/NA EARO option seen for that node. A NS/NA with an EARO and a NS/NA
Internet-Draft An Update to 6LoWPAN ND February
without a EARO thus represent different nodes; if they relate to a without a EARO thus represent different nodes; if they relate to a
same target then an address duplication is likely. same target then an address duplication is likely.
The Registration Unique ID in [RFC6775] is a EUI-64 globally unique The Registration Unique ID in [RFC6775] is a EUI-64 globally unique
address configured at a Lower Layer, under the assumption that address configured at a Lower Layer, under the assumption that
duplicate EUI-64 addresses are avoided. duplicate EUI-64 addresses are avoided.
With this specification, the Registration Unique ID is allowed to be With this specification, the Registration Unique ID is allowed to be
extended to different types of identifier, as long as the type is extended to different types of identifier, as long as the type is
clearly indicated. For instance, the type can be a cryptographic clearly indicated. For instance, the type can be a cryptographic
skipping to change at page 10, line 42 skipping to change at page 10, line 23
TID field is added to the Extended DAR (EDAR) and the Extended DAC TID field is added to the Extended DAR (EDAR) and the Extended DAC
(EDAC) messages as a replacement to a Reserved field, and an odd (EDAC) messages as a replacement to a Reserved field, and an odd
value of the ICMP Code indicates support for the TID, to transport value of the ICMP Code indicates support for the TID, to transport
the "T" flag. the "T" flag.
In order to prepare for future extensions, and though no option has In order to prepare for future extensions, and though no option has
been defined for the Duplicate Address messages, implementations been defined for the Duplicate Address messages, implementations
SHOULD expect ND options after the main body, and SHOULD ignore them. SHOULD expect ND options after the main body, and SHOULD ignore them.
As for the EARO, the Extended Duplicate Address messages are backward As for the EARO, the Extended Duplicate Address messages are backward
compatible with the legacy versions, and remarks concerning backwards compatible with the RFC6775-only versions, and remarks concerning
compatibility for the protocol between the 6LN and the 6LR apply backwards compatibility for the protocol between the 6LN and the 6LR
similarly between a 6LR and a 6LBR. apply similarly between a 6LR and a 6LBR.
4.5. Registering the Target Address 4.5. Registering the Target Address
The Registering Node is the node that performs the registration to The Registering Node is the node that performs the registration to
the 6BBR. As in [RFC6775], it may be the Registered Node as well, in the 6BBR. As in [RFC6775], it may be the Registered Node as well, in
which case it registers one of its own addresses, and indicates its which case it registers one of its own addresses, and indicates its
own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO). own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO).
This specification adds the capability to proxy the registration This specification adds the capability to proxy the registration
operation on behalf of a Registered Node that is reachable over a LLN operation on behalf of a Registered Node that is reachable over a LLN
Internet-Draft An Update to 6LoWPAN ND February
mesh. In that case, if the Registered Node is reachable from the mesh. In that case, if the Registered Node is reachable from the
6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC 6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC
Address of the Registered Node as SLLA in the NS(EARO). If the Address of the Registered Node as SLLA in the NS(EARO). If the
Registered Node is reachable over a Route-Over mesh from the Registered Node is reachable over a Route-Over mesh from the
Registering Node, the SLLA in the NS(ARO) is that of the Registering Registering Node, the SLLA in the NS(ARO) is that of the Registering
Node. This enables the Registering Node to attract the packets from Node. This enables the Registering Node to attract the packets from
the 6BBR and route them over the LLN to the Registered Node. the 6BBR and route them over the LLN to the Registered Node.
In order to enable the latter operation, this specification changes In order to enable the latter operation, this specification changes
the behavior of the 6LN and the 6LR so that the Registered Address is the behavior of the 6LN and the 6LR so that the Registered Address is
found in the Target Address field of the NS and NA messages as found in the Target Address field of the NS and NA messages as
opposed to the Source Address. With this convention, a TLLA option opposed to the Source Address. With this convention, a TLLA option
indicates the link-layer address of the 6LN that owns the address, indicates the link-layer address of the 6LN that owns the address,
whereas the SLLA Option in a NS message indicates that of the whereas the SLLA Option in a NS message indicates that of the
Registering Node, which can be the owner device, or a proxy. Registering Node, which can be the owner device, or a proxy.
The Registering Node is reachable from the 6LR, and is also the one The Registering Node is reachable from the 6LR, and is also the one
expecting packets for the 6LN. Therefore, it MUST place its own Link expecting packets for the 6LN. Therefore, it MUST place its own Link
Layer Address in the SLLA Option that MUST always be placed in a Layer Address in the SLLA Option that MUST always be placed in a
registration NS(EARO) message. This maintains compatibility with registration NS(EARO) message. This maintains compatibility with
legacy 6LoWPAN ND [RFC6775]. RFC6775-only 6LoWPAN ND [RFC6775].
4.6. Link-Local Addresses and Registration 4.6. Link-Local Addresses and Registration
Considering that LLN nodes are often not wired and may move, there is Considering that LLN nodes are often not wired and may move, there is
no guarantee that a Link-Local address stays unique between a no guarantee that a Link-Local address stays unique between a
potentially variable and unbounded set of neighboring nodes. potentially variable and unbounded set of neighboring nodes.
Compared to [RFC6775], this specification only requires that a Link- Compared to [RFC6775], this specification only requires that a Link-
Local address is unique from the perspective of the two nodes that Local address is unique from the perspective of the two nodes that
use it to communicate (e.g. the 6LN and the 6LR in an NS/NA use it to communicate (e.g. the 6LN and the 6LR in an NS/NA
skipping to change at page 12, line 4 skipping to change at page 11, line 37
they are reachable over one hop and that at least one of the 2 nodes they are reachable over one hop and that at least one of the 2 nodes
acts as a 6LR. A node MUST register a Link-Local address to a 6LR in acts as a 6LR. A node MUST register a Link-Local address to a 6LR in
order to obtain reachability from that 6LR beyond the current order to obtain reachability from that 6LR beyond the current
exchange, and in particular to use the Link-Local address as source exchange, and in particular to use the Link-Local address as source
address to register other addresses, e.g. global addresses. address to register other addresses, e.g. global addresses.
If there is no collision with an address previously registered to If there is no collision with an address previously registered to
this 6LR by another 6LN, then the Link-Local address is unique from this 6LR by another 6LN, then the Link-Local address is unique from
the standpoint of this 6LR and the registration is acceptable. the standpoint of this 6LR and the registration is acceptable.
Alternatively, two different 6LRs might expose the same Link-Local Alternatively, two different 6LRs might expose the same Link-Local
Internet-Draft An Update to 6LoWPAN ND February
address but different link-layer addresses. In that case, a 6LN MUST address but different link-layer addresses. In that case, a 6LN MUST
only interact with at most one of the 6LRs. only interact with at most one of the 6LRs.
The DAD process between the 6LR and a 6LBR, which is based on an The DAD process between the 6LR and a 6LBR, which is based on an
exchange of Duplicate Address messages, does not need to take place exchange of Duplicate Address messages, does not need to take place
for Link-Local addresses. for Link-Local addresses.
When registering to a 6LR that conforms this specification, a node When registering to a 6LR that conforms this specification, a node
MUST use a Link-Local address as the source address of the MUST use a Link-Local address as the source address of the
registration, whatever the type of IPv6 address that is being registration, whatever the type of IPv6 address that is being
skipping to change at page 13, line 4 skipping to change at page 12, line 36
4.7. Maintaining the Registration States 4.7. Maintaining the Registration States
This section discusses protocol actions that involve the Registering This section discusses protocol actions that involve the Registering
Node, the 6LR and the 6LBR. It must be noted that the portion that Node, the 6LR and the 6LBR. It must be noted that the portion that
deals with a 6LBR only applies to those addresses that are registered deals with a 6LBR only applies to those addresses that are registered
to it; as discussed in Section 4.6, this is not the case for Link- to it; as discussed in Section 4.6, this is not the case for Link-
Local addresses. The registration state includes all data that is Local addresses. The registration state includes all data that is
stored in the router relative to that registration, in particular, stored in the router relative to that registration, in particular,
but not limited to, an NCE in a 6LR. 6LBRs and 6BBRs may store but not limited to, an NCE in a 6LR. 6LBRs and 6BBRs may store
additional registration information in more complex data structures additional registration information in more complex data structures
Internet-Draft An Update to 6LoWPAN ND February
and use protocols that are out of scope of this document to keep them and use protocols that are out of scope of this document to keep them
synchronized when they are distributed. synchronized when they are distributed.
When its Neighbor Cache is full, a 6LR cannot accept a new When its Neighbor Cache is full, a 6LR cannot accept a new
registration. In that situation, the EARO is returned in a NA registration. In that situation, the EARO is returned in a NA
message with a Status of 2, and the Registering Node may attempt to message with a Status of 2, and the Registering Node may attempt to
register to another 6LR. register to another 6LR.
If the registry in the 6LBR is saturated, the LBR cannot guarantee If the registry in the 6LBR is saturated, then the LBR cannot decide
that a new address is effectively not a duplicate. In that case, the whether a new address is a duplicate. In that case, the 6LBR replies
6LBR replies to a EDAR message with a EDAC message that carries a new to a EDAR message with a EDAC message that carries a new Status Code
Status Code indicating "6LBR Registry saturated" Table 1. Note: this indicating "6LBR Registry saturated" Table 1. Note: this code is
code is used by 6LBRs instead of Status 2 when responding to a used by 6LBRs instead of Status 2 when responding to a Duplicate
Duplicate Address message exchange and passed on to the Registering Address message exchange and passed on to the Registering Node by the
Node by the 6LR. There is no point for the node to retry this 6LR. There is no point for the node to retry this registration
registration immediately via another 6LR, since the problem is global immediately via another 6LR, since the problem is global to the
to the network. The node may either abandon that address, de- network. The node may either abandon that address, de-register other
register other addresses first to make room, or keep the address in addresses first to make room, or keep the address in TENTATIVE state
TENTATIVE state and retry later. and retry later.
A node renews an existing registration by sending a new NS(EARO) A node renews an existing registration by sending a new NS(EARO)
message for the Registered Address. In order to refresh the message for the Registered Address. In order to refresh the
registration state in the 6LBR, the registration MUST be reported to registration state in the 6LBR, the registration MUST be reported to
the 6LBR. the 6LBR.
A node that ceases to use an address SHOULD attempt to de-register A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it has registered the that address from all the 6LRs to which it has registered the
address, which is achieved using an NS(EARO) message with a address, which is achieved using an NS(EARO) message with a
Registration Lifetime of 0. Registration Lifetime of 0.
A node that moves away from a particular 6LR SHOULD attempt to de- A node that moves away from a particular 6LR SHOULD attempt to de-
register all of its addresses registered to that 6LR and register to register all of its addresses registered to that 6LR and register to
a new 6LR with an incremented TID. When/if the node shows up a new 6LR with an incremented TID. When/if the node shows up
elsewhere, an asynchronous NA(EARO) or EDAC message with a status of elsewhere, an asynchronous NA(EARO) or EDAC message with a status of
3 "Moved" SHOULD be used to clean up the state in the previous 3 "Moved" SHOULD be used to clean up the state in the previous
location. For instance, as described in location. For instance, as described in
[I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a [I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a
6BBR in a NA(EARO) message to indicate that the ownership of the 6BBR in a NA(EARO) message to indicate that the ownership of the
proxy state on the Backbone was transferred to another 6BBR, as the proxy state on the Backbone Link was transferred to another 6BBR, as
consequence of a movement of the device. The receiver of the message the consequence of a movement of the device. The receiver of the
SHOULD propagate the status down the chain towards the Registered message SHOULD propagate the status down the chain towards the
node (e.g. reversing an existing RPL [RFC6550] path) and then clean Registered node (e.g. reversing an existing RPL [RFC6550] path) and
up its state. then clean up its state.
Upon receiving a NS(EARO) message with a Registration Lifetime of 0 Upon receiving a NS(EARO) message with a Registration Lifetime of 0
and determining that this EARO is the freshest for a given NCE (see and determining that this EARO is the freshest for a given NCE (see
Section 4.2), a 6LR cleans up its NCE. If the address was registered Section 4.2), a 6LR cleans up its NCE. If the address was registered
to the 6LBR, then the 6LR MUST report to the 6LBR, through a to the 6LBR, then the 6LR MUST report to the 6LBR, through a
Internet-Draft An Update to 6LoWPAN ND February
Duplicate Address exchange with the 6LBR, indicating the null Duplicate Address exchange with the 6LBR, indicating the null
Registration Lifetime and the latest TID that this 6LR is aware of. Registration Lifetime and the latest TID that this 6LR is aware of.
Upon receiving the Extended DAR message, the 6LBR evaluates if this Upon receiving the Extended DAR message, the 6LBR evaluates if this
is the most recent TID it has received for that particular registry is the most recent TID it has received for that particular registry
entry. If so, then the entry is scheduled to be removed, and the entry. If so, then the entry is scheduled to be removed, and the
EDAR is answered with a EDAC message bearing a Status of 0 EDAR is answered with a EDAC message bearing a Status of 0
("Success"). Otherwise, a Status 3 ("Moved") is returned instead, ("Success"). Otherwise, a Status 3 ("Moved") is returned instead,
and the existing entry is maintained. and the existing entry is maintained.
skipping to change at page 15, line 4 skipping to change at page 14, line 36
the following subsections. the following subsections.
6.1. Enhanced Address Registration Option (EARO) 6.1. Enhanced Address Registration Option (EARO)
The Address Registration Option (ARO) is defined in section 4.1. of The Address Registration Option (ARO) is defined in section 4.1. of
[RFC6775]. [RFC6775].
The Enhanced Address Registration Option (EARO) updates the ARO The Enhanced Address Registration Option (EARO) updates the ARO
option within Neighbor Discovery NS and NA messages between a 6LN and option within Neighbor Discovery NS and NA messages between a 6LN and
its 6LR. On the other hand, the Extended Duplicate Address messages, its 6LR. On the other hand, the Extended Duplicate Address messages,
Internet-Draft An Update to 6LoWPAN ND February
EDAR and EDAC, replace the DAR and DAC messages so as to transport EDAR and EDAC, replace the DAR and DAC messages so as to transport
the new information between 6LRs and 6LBRs across LLN meshes such as the new information between 6LRs and 6LBRs across LLN meshes such as
6TiSCH networks. 6TiSCH networks.
An NS message with an EARO option is a registration if and only if it An NS message with an EARO option is a registration if and only if it
also carries an SLLAO option. The EARO option also used in NS and NA also carries an SLLAO option. The EARO option also used in NS and NA
messages between Backbone Routers [I-D.ietf-6lo-backbone-router] over messages between Backbone Routers [I-D.ietf-6lo-backbone-router] over
the Backbone link to sort out the distributed registration state; in the Backbone Link to sort out the distributed registration state; in
that case, it does not carry the SLLAO option and is not confused that case, it does not carry the SLLAO option and is not confused
with a registration. with a registration.
When using the EARO option, the address being registered is found in When using the EARO option, the address being registered is found in
the Target Address field of the NS and NA messages. the Target Address field of the NS and NA messages.
The EARO extends the ARO and is indicated by the "T" flag set. The The EARO extends the ARO and is indicated by the "T" flag set. The
format of the EARO option is as follows: format of the EARO option is as follows:
0 1 2 3 0 1 2 3
skipping to change at page 16, line 4 skipping to change at page 15, line 34
Status: 8-bit unsigned integer. Indicates the status of a Status: 8-bit unsigned integer. Indicates the status of a
registration in the NA response. MUST be set to 0 in registration in the NA response. MUST be set to 0 in
NS messages. See Table 1 below. NS messages. See Table 1 below.
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| Value | Description | | Value | Description |
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| 0..2 | See [RFC6775]. Note: a Status of 1 "Duplicate Address" | | 0..2 | See [RFC6775]. Note: a Status of 1 "Duplicate Address" |
| | applies to the Registered Address. If the Source Address | | | applies to the Registered Address. If the Source Address |
| | conflicts with an existing registration, "Duplicate | | | conflicts with an existing registration, "Duplicate |
Internet-Draft An Update to 6LoWPAN ND February
| | Source Address" should be used. | | | Source Address" should be used. |
| | | | | |
| 3 | Moved: The registration failed because it is not the | | 3 | Moved: The registration failed because it is not the |
| | freshest. This Status indicates that the registration is | | | freshest. This Status indicates that the registration is |
| | rejected because another more recent registration was | | | rejected because another more recent registration was |
| | done, as indicated by a same OUI and a more recent TID. | | | done, as indicated by a same RUID and a more recent TID. |
| | One possible cause is a stale registration that has | | | One possible cause is a stale registration that has |
| | progressed slowly in the network and was passed by a more | | | progressed slowly in the network and was passed by a more |
| | recent one. It could also indicate a OUI collision. | | | recent one. It could also indicate a RUID collision. |
| | | | | |
| 4 | Removed: The binding state was removed. This may be | | 4 | Removed: The binding state was removed. This may be |
| | placed in an asynchronous NS(ARO) message, or as the | | | placed in an asynchronous NS(ARO) message, or as the |
| | rejection of a proxy registration to a Backbone Router | | | rejection of a proxy registration to a Backbone Router |
| | | | | |
| 5 | Validation Requested: The Registering Node is challenged | | 5 | Validation Requested: The Registering Node is challenged |
| | for owning the Registered Address or for being an | | | for owning the Registered Address or for being an |
| | acceptable proxy for the registration. This Status is | | | acceptable proxy for the registration. This Status is |
| | expected in asynchronous messages from a registrar (6LR, | | | expected in asynchronous messages from a registrar (6LR, |
| | 6LBR, 6BBR) to indicate that the registration state is | | | 6LBR, 6BBR) to indicate that the registration state is |
skipping to change at page 17, line 4 skipping to change at page 16, line 31
| | passed on to the Registering Node by the 6LR. | | | passed on to the Registering Node by the 6LR. |
| | | | | |
| 10 | Validation Failed: The proof of ownership of the | | 10 | Validation Failed: The proof of ownership of the |
| | registered address is not correct. | | | registered address is not correct. |
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
Table 1: EARO Status Table 1: EARO Status
Reserved: This field is unused. It MUST be initialized to zero Reserved: This field is unused. It MUST be initialized to zero
by the sender and MUST be ignored by the receiver. by the sender and MUST be ignored by the receiver.
T: One bit flag. Set if the next octet is used as a
Internet-Draft An Update to 6LoWPAN ND February
T: One bit flag. Set if the next octet is a used as a
TID. TID.
TID: 1-byte integer; a transaction id that is maintained TID: 1-byte integer; a transaction id that is maintained
by the node and incremented with each transaction. by the node and incremented with each transaction.
The node SHOULD maintain the TID in a persistent The node SHOULD maintain the TID in a persistent
storage. storage.
Registration Lifetime: 16-bit integer; expressed in minutes. 0 Registration Lifetime: 16-bit integer; expressed in minutes. 0
means that the registration has ended and the means that the registration has ended and the
associated state should be removed. associated state should be removed.
Registration Unique IDentifier (RUID): A globally unique identifier
Registration Unique IDentifier (OUI): A globally unique identifier
for the node associated. This can be the EUI-64 for the node associated. This can be the EUI-64
derived IID of an interface, or some provable ID derived IID of an interface, or some provable ID
obtained cryptographically. obtained cryptographically.
6.2. Extended Duplicate Address Message Formats 6.2. Extended Duplicate Address Message Formats
The Duplicate Address Request (DAR) and the Duplicate Address The Duplicate Address Request (DAR) and the Duplicate Address
Confirmation (DAC) messages are defined in section 4.4 of [RFC6775]. Confirmation (DAC) messages are defined in section 4.4 of [RFC6775].
Those messages follow a common base format, which enables information Those messages follow a common base format, which enables information
from the ARO to be transported over multiple hops. from the ARO to be transported over multiple hops.
The Duplicate Address Messages are extended to adapt to the Extended The Duplicate Address Messages are extended to adapt to the Extended
ARO format, as follows: ARO format, as follows:
Internet-Draft An Update to 6LoWPAN ND February
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum | | Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status | TID | Registration Lifetime | | Status | TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Registration Unique ID (EUI-64 or equivalent) + + Registration Unique ID (EUI-64 or equivalent) +
| | | |
skipping to change at page 18, line 35 skipping to change at page 17, line 36
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Duplicate Address Messages Format Figure 3: Duplicate Address Messages Format
Modified Message Fields Modified Message Fields
Code: The ICMP Code as defined in [RFC4443]. The ICMP Code Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
MUST be set to 1 with this specification. An odd MUST be set to 1 with this specification. An odd
value of the ICMP Code indicates that the TID field value of the ICMP Code indicates that the TID field
is present and obeys this specification. is present and obeys this specification.
TID: 1-byte integer; same definition and processing as the TID: 1-byte integer; same definition and processing as the
TID in the EARO option as defined in Section 6.1. TID in the EARO option as defined in Section 6.1.
Registration Unique IDentifier (RUID): 8 bytes; same definition and
Registration Unique IDentifier (OUI): 8 bytes; same definition and processing as the RUID in the EARO option as defined
processing as the OUI in the EARO option as defined
in Section 6.1. in Section 6.1.
6.3. New 6LoWPAN Capability Bits in the Capability Indication Option 6.3. New 6LoWPAN Capability Bits in the Capability Indication Option
This specification defines new capability bits for use in the 6CIO, This specification defines new capability bits for use in the 6CIO,
which was introduced by [RFC7400] for use in IPv6 ND RA messages. which was introduced by [RFC7400] for use in IPv6 ND RA messages.
Routers that support this specification MUST set the "E" flag and 6LN Routers that support this specification MUST set the "E" flag and 6LN
SHOULD favor 6LR routers that support this specification over those SHOULD favor 6LR routers that support this specification over those
that do not. Routers that are capable of acting as 6LR, 6LBR and that do not. Routers that are capable of acting as 6LR, 6LBR and
6BBR SHOULD set the "L", "B" and "P" flags, respectively. In 6BBR SHOULD set the "L", "B" and "P" flags, respectively. In
particular, the function 6LR is often collocated with that of 6LBR. particular, the function 6LR is often collocated with that of 6LBR.
Internet-Draft An Update to 6LoWPAN ND February
Those flags are not mutually exclusive and if a router is capable of Those flags are not mutually exclusive and if a router is capable of
performing multiple functions, it SHOULD set all the related flags. performing multiple functions, it SHOULD set all the related flags.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 1 | Reserved |L|B|P|E|G| | Type | Length = 1 | Reserved |L|B|P|E|G|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 19, line 51 skipping to change at page 18, line 45
A router that supports this specification SHOULD indicate that with a A router that supports this specification SHOULD indicate that with a
6CIO. 6CIO.
If the Registering Node receives a 6CIO in a Router Advertisement If the Registering Node receives a 6CIO in a Router Advertisement
message, then the setting of the "E" Flag indicates whether or not message, then the setting of the "E" Flag indicates whether or not
this specification is supported. this specification is supported.
7.1.2. Using the "T" Flag in the EARO 7.1.2. Using the "T" Flag in the EARO
One alternate way for a 6LN to discover the router's capabilities is One alternate way for a 6LN to discover the router's capabilities is
to first register a Link Local address, placing the same address in to start by registering a Link Local address, placing the same
the Source and Target Address fields of the NS message, and setting address in the Source and Target Address fields of the NS message,
the "T" Flag. The node may for instance register an address that is and setting the "T" Flag. The node may for instance register an
address that is based on EUI-64. For such an address, DAD is not
Internet-Draft An Update to 6LoWPAN ND February required and using the SLLAO option in the NS is actually more
consistent with existing ND specifications such as the "Optimistic
based on EUI-64. For such an address, DAD is not required and using Duplicate Address Detection (ODAD) for IPv6" [RFC4429].
the SLLAO option in the NS is actually more consistent with existing
ND specifications such as the "Optimistic Duplicate Address Detection
(ODAD) for IPv6" [RFC4429].
Once its first registration is complete, the node knows from the Once its first registration is complete, the node knows from the
setting of the "T" Flag in the response whether the router supports setting of the "T" Flag in the response whether the router supports
this specification. If support is verified, the node may register this specification. If support is verified, the node may register
other addresses that it owns, or proxy-register addresses on behalf other addresses that it owns, or proxy-register addresses on behalf
some another node, indicating those addresses being registered in the some another node, indicating those addresses being registered in the
Target Address field of the NS messages, while using one of its own Target Address field of the NS messages, while using one of its own
previously registered addresses as source. previously registered addresses as source.
A node that supports this specification MUST always use an EARO as a A node that supports this specification MUST always use an EARO as a
replacement to an ARO in its registration to a router. This is replacement to an ARO in its registration to a router. This is
harmless since the "T" flag and TID field are reserved in [RFC6775], harmless since the "T" flag and TID field are reserved in [RFC6775],
and are ignored by a legacy router. A router that supports this and are ignored by a RFC6775-only router. A router that supports
specification answers an ARO with an ARO and answers an EARO with an this specification answers an ARO with an ARO and answers an EARO
EARO. with an EARO.
This specification changes the behavior of the peers in a This specification changes the behavior of the peers in a
registration flow. To enable backward compatibility, a 6LN that registration flow. To enable backward compatibility, a 6LN that
registers to a 6LR that is not known to support this specification registers to a 6LR that is not known to support this specification
MUST behave in a manner that is compatible with [RFC6775]. A 6LN can MUST behave in a manner that is compatible with [RFC6775]. A 6LN can
achieve that by sending a NS(EARO) message with a Link-Local Address achieve that by sending a NS(EARO) message with a Link-Local Address
used as both Source and Target Address, as described in Section 4.6. used as both Source and Target Address, as described in Section 4.6.
Once the 6LR is known to support this specification, the 6LN MUST Once the 6LR is known to support this specification, the 6LN MUST
obey this specification. obey this specification.
7.2. Legacy 6LoWPAN Node 7.2. RFC6775-only 6LoWPAN Node
A legacy 6LN will use the Registered Address as source and will not A RFC6775-only 6LN will use the Registered Address as source and will
use an EARO option. An updated 6LR MUST accept that registration if not use an EARO option. An updated 6LR MUST accept that registration
it is valid per [RFC6775], and it MUST manage the binding cache if it is valid per [RFC6775], and it MUST manage the binding cache
accordingly. The updated 6LR MUST then use the legacy Duplicate accordingly. The updated 6LR MUST then use the RFC6775-only
Address messages as specified in [RFC6775] to indicate to the 6LBR Duplicate Address messages as specified in [RFC6775] to indicate to
that the TID is not present in the messages. the 6LBR that the TID is not present in the messages.
The main difference with [RFC6775] is that Duplicate Address exchange The main difference with [RFC6775] is that Duplicate Address exchange
for DAD is avoided for Link-Local addresses. In any case, the 6LR for DAD is avoided for Link-Local addresses. In any case, the 6LR
SHOULD use an EARO in the reply, and may use any of the Status codes SHOULD use an EARO in the reply, and may use any of the Status codes
defined in this specification. defined in this specification.
7.3. Legacy 6LoWPAN Router 7.3. RFC6775-only 6LoWPAN Router
The first registration by an updated 6LN MUST be for a Link-Local The first registration by an updated 6LN MUST be for a Link-Local
address, using that Link-Local address as source. A legacy 6LR will address, using that Link-Local address as source. A RFC6775-only 6LR
will not make a difference and treat that registration as if the 6LN
Internet-Draft An Update to 6LoWPAN ND February was a RFC6775-only node.
not make a difference and treat that registration as if the 6LN was a
legacy node.
An updated 6LN will always use an EARO option in the registration NS An updated 6LN will always use an EARO option in the registration NS
message, whereas a legacy 6LR will always reply with an ARO option in message, whereas a RFC6775-only 6LR will always reply with an ARO
the NA message. From that first registration, the updated 6LN can option in the NA message. From that first registration, the updated
determine whether or not the 6LR supports this specification. 6LN can determine whether or not the 6LR supports this specification.
After detecting a legacy 6LR, an updated 6LN SHOULD attempt to find After detecting a RFC6775-only 6LR, an updated 6LN SHOULD attempt to
an alternate 6LR that is updated for a reasonable time that depends find an alternate 6LR that is updated for a reasonable time that
on the type of device and the expected deployment. depends on the type of device and the expected deployment.
An updated 6LN SHOULD use an EARO in the request regardless of the An updated 6LN SHOULD use an EARO in the request regardless of the
type of 6LR, legacy or updated, which implies that the "T" flag is type of 6LR, RFC6775-only or updated, which implies that the "T" flag
set. is set.
If an updated 6LN moves from an updated 6LR to a legacy 6LR, the If an updated 6LN moves from an updated 6LR to a RFC6775-only 6LR,
legacy 6LR will send a legacy DAR message, which can not be compared the RFC6775-only 6LR will send a RFC6775-only DAR message, which can
with an updated one for freshness. not be compared with an updated one for freshness.
Allowing legacy DAR messages to replace a state established by the Allowing RFC6775-only DAR messages to replace a state established by
updated protocol in the 6LBR would be an attack vector and that the updated protocol in the 6LBR would be an attack vector and that
cannot be the default behavior. cannot be the default behavior.
But if legacy and updated 6LRs coexist temporarily in a network, then But if RFC6775-only and updated 6LRs coexist temporarily in a
it makes sense for an administrator to install a policy that allows network, then it makes sense for an administrator to install a policy
so, and the capability to install such a policy should be that allows so, and the capability to install such a policy should be
configurable in a 6LBR though it is out of scope for this document. configurable in a 6LBR though it is out of scope for this document.
7.4. Legacy 6LoWPAN Border Router 7.4. RFC6775-only 6LoWPAN Border Router
With this specification, the Duplicate Address messages are extended With this specification, the Duplicate Address messages are extended
to transport the EARO information. Similarly to the NS/NA exchange, to transport the EARO information. Similarly to the NS/NA exchange,
updated 6LBR devices always use the Extended Duplicate Address updated 6LBR devices always use the Extended Duplicate Address
messages and all the associated behavior so they can always be messages and all the associated behavior so they can always be
differentiated from legacy ones. differentiated from RFC6775-only ones.
Note that a legacy 6LBR will accept and process an EDAR message as if Note that a RFC6775-only 6LBR will accept and process an EDAR message
it was a legacy DAR, so legacy support of DAD is preserved. as if it was a RFC6775-only DAR, so the support of DAD is preserved.
8. Security Considerations 8. Security Considerations
This specification extends [RFC6775], and the security section of This specification extends [RFC6775], and the security section of
that draft also applies to this as well. In particular, it is that standard also applies to this as well. In particular, it is
expected that the link layer is sufficiently protected to prevent a expected that the link layer is sufficiently protected to prevent a
rogue access, either by means of physical or IP security on the rogue access, either by means of physical or IP security on the
Backbone Link and link layer cryptography on the LLN. Backbone Link and link layer cryptography on the LLN.
Internet-Draft An Update to 6LoWPAN ND February
This specification also expects that the LLN MAC provides secure This specification also expects that the LLN MAC provides secure
unicast to/from the Backbone Router and secure Broadcast from the unicast to/from the Backbone Router and secure Broadcast from the
Backbone Router in a way that prevents tampering with or replaying Backbone Router in a way that prevents tampering with or replaying
the RA messages. the RA messages.
This specification recommends using privacy techniques (see This specification recommends using privacy techniques (see
Section 9), and protection against address theft such as provided by Section 9), and protection against address theft such as provided by
"Address Protected Neighbor Discovery for Low-power and Lossy "Address Protected Neighbor Discovery for Low-power and Lossy
Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the
Registered Address using a cryptographic RUID. Registered Address using a cryptographic RUID.
The registration mechanism may be used by a rogue node to attack the The registration mechanism may be used by a rogue node to attack the
6LR or the 6LBR with a Denial-of-Service attack against the registry. 6LR or the 6LBR with a Denial-of-Service attack against the registry.
It may also happen that the registry of a 6LR or a 6LBR is saturated It may also happen that the registry of a 6LR or a 6LBR is saturated
and cannot take any more registration, which effectively denies the and cannot take any more registration, which effectively denies the
requesting a node the capability to use a new address. In order to requesting node the capability to use a new address. In order to
alleviate those concerns, Section 4.7 provides a number of alleviate those concerns, Section 4.7 provides a number of
recommendations that ensure that a stale registration is removed as recommendations that ensure that a stale registration is removed as
soon as possible from the 6LR and 6LBR. In particular, this soon as possible from the 6LR and 6LBR. In particular, this
specification recommends that: specification recommends that:
o A node that ceases to use an address SHOULD attempt to de-register o A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it is registered. See that address from all the 6LRs to which it is registered. See
Section 4.2 for the mechanism to avoid replay attacks and avoiding Section 4.2 for the mechanism to avoid replay attacks and avoiding
the use of stale registration information. the use of stale registration information.
o The Registration lifetimes SHOULD be individually configurable for o The Registration lifetimes SHOULD be individually configurable for
each address or group of addresses. The nodes SHOULD be each address or group of addresses. The nodes SHOULD be
configured with a Registration Lifetime that reflects their configured with a Registration Lifetime that reflects their
expectation of how long they will use the address with the 6LR to expectation of how long they will use the address with the 6LR to
which it is registered. In particular, use cases that involve which it is registered. In particular, use cases that involve
mobility or rapid address changes SHOULD use lifetimes that are mobility or rapid address changes SHOULD use lifetimes that are
larger yet of a same order as the duration of the expectation of larger yet of a same order as the duration of the expectation of
presence. presence.
o The router (6LR or 6LBR) SHOULD be configurable so as to limit the o The router (6LR or 6LBR) SHOULD be configurable so as to limit the
number of addresses that can be registered by a single node, as number of addresses that can be registered by a single node, as
identified at least by MAC address and preferably by security identified at least by MAC address and preferably by security
credentials. When that maximum is reached, the router should use credentials. When that maximum is reached, the router should use
a Least-Recently-Used (LRU) algorithm to clean up the addresses, a Least-Recently-Used (LRU) algorithm to clean up the addresses,
keeping at least one Link-Local address. The router SHOULD keeping at least one Link-Local address. The router SHOULD
attempt to keep one or more stable addresses if stability can be attempt to keep one or more stable addresses if stability can be
determined, e.g. from the way the IID is formed or because they determined, e.g. from the way the IID is formed or because they
are used over a much longer time span than other (privacy, are used over a much longer time span than other (privacy,
shorter-lived) addresses. Address lifetimes SHOULD be shorter-lived) addresses. Address lifetimes SHOULD be
skipping to change at page 23, line 4 skipping to change at page 21, line 44
number of addresses that can be registered by a single node, as number of addresses that can be registered by a single node, as
identified at least by MAC address and preferably by security identified at least by MAC address and preferably by security
credentials. When that maximum is reached, the router should use credentials. When that maximum is reached, the router should use
a Least-Recently-Used (LRU) algorithm to clean up the addresses, a Least-Recently-Used (LRU) algorithm to clean up the addresses,
keeping at least one Link-Local address. The router SHOULD keeping at least one Link-Local address. The router SHOULD
attempt to keep one or more stable addresses if stability can be attempt to keep one or more stable addresses if stability can be
determined, e.g. from the way the IID is formed or because they determined, e.g. from the way the IID is formed or because they
are used over a much longer time span than other (privacy, are used over a much longer time span than other (privacy,
shorter-lived) addresses. Address lifetimes SHOULD be shorter-lived) addresses. Address lifetimes SHOULD be
individually configurable. individually configurable.
Internet-Draft An Update to 6LoWPAN ND February
o In order to avoid denial of registration for the lack of o In order to avoid denial of registration for the lack of
resources, administrators should take great care to deploy resources, administrators should take great care to deploy
adequate numbers of 6LRs to cover the needs of the nodes in their adequate numbers of 6LRs to cover the needs of the nodes in their
range, so as to avoid a situation of starving nodes. It is range, so as to avoid a situation of starving nodes. It is
expected that the 6LBR that serves a LLN is a more capable node expected that the 6LBR that serves a LLN is a more capable node
then the average 6LR, but in a network condition where it may then the average 6LR, but in a network condition where it may
become saturated, a particular deployment should distribute the become saturated, a particular deployment should distribute the
6LBR functionality, for instance by leveraging a high speed 6LBR functionality, for instance by leveraging a high speed
Backbone and Backbone Routers to aggregate multiple LLNs into a Backbone Link and Backbone Routers to aggregate multiple LLNs into
larger subnet. a larger subnet.
The LLN nodes depend on the 6LBR and the 6BBR for their operation. A The LLN nodes depend on the 6LBR and the 6BBR for their operation. A
trust model must be put in place to ensure that the right devices are trust model must be put in place to ensure that the right devices are
acting in these roles, so as to avoid threats such as black-holing, acting in these roles, so as to avoid threats such as black-holing,
or bombing attack whereby an impersonated 6LBR would destroy state in or bombing attack whereby an impersonated 6LBR would destroy state in
the network by using the "Removed" Status code. This trust model the network by using the "Removed" Status code. This trust model
could be at a minimum based on a Layer-2 access control, or could could be at a minimum based on a Layer-2 access control, or could
provide role validation as well (see Req5.1 in Appendix B.5). provide role validation as well (see Req5.1 in Appendix B.5).
9. Privacy Considerations 9. Privacy Considerations
As indicated in section Section 2, this protocol does not aim at As indicated in Section 3, this protocol does not aim at limiting the
limiting the number of IPv6 addresses that a device can form. A host number of IPv6 addresses that a device can form. A host should be
should be able to form and register any address that is topologically able to form and register any address that is topologically correct
correct in the subnet(s) advertised by the 6LR/6LBR. in the subnet(s) advertised by the 6LR/6LBR.
This specification does not mandate any particular way for forming This specification does not mandate any particular way for forming
IPv6 addresses, but it discourages using EUI-64 for forming the IPv6 addresses, but it discourages using EUI-64 for forming the
Interface ID in the Link-Local address because this method prevents Interface ID in the Link-Local address because this method prevents
the usage of "SEcure Neighbor Discovery (SEND)" [RFC3971] and the usage of "SEcure Neighbor Discovery (SEND)" [RFC3971] and
"Cryptographically Generated Addresses (CGA)" [RFC3972], and that of "Cryptographically Generated Addresses (CGA)" [RFC3972], and that of
address privacy techniques. address privacy techniques.
"Privacy Considerations for IPv6 Adaptation-Layer Mechanisms" "Privacy Considerations for IPv6 Adaptation-Layer Mechanisms"
[RFC8065] explains why privacy is important and how to form privacy- [RFC8065] explains why privacy is important and how to form privacy-
skipping to change at page 24, line 4 skipping to change at page 22, line 43
The IPv6 address of the 6LN in the IPv6 header can be compressed The IPv6 address of the 6LN in the IPv6 header can be compressed
statelessly when the Interface Identifier in the IPv6 address can be statelessly when the Interface Identifier in the IPv6 address can be
derived from the Lower Layer address. When it is not critical to derived from the Lower Layer address. When it is not critical to
benefit from that compression, e.g. the address can be compressed benefit from that compression, e.g. the address can be compressed
statefully, or it is rarely used and/or it is used only over one hop, statefully, or it is rarely used and/or it is used only over one hop,
then privacy concerns should be considered. In particular, new then privacy concerns should be considered. In particular, new
implementations should follow the IETF "Recommendation on Stable IPv6 implementations should follow the IETF "Recommendation on Stable IPv6
Interface Identifiers" [RFC8064] This RFC recommends the use of "A Interface Identifiers" [RFC8064] This RFC recommends the use of "A
Method for Generating Semantically Opaque Interface Identifiers with Method for Generating Semantically Opaque Interface Identifiers with
Internet-Draft An Update to 6LoWPAN ND February
IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for
generating Interface Identifiers to be used in SLAAC. generating Interface Identifiers to be used in SLAAC.
10. IANA Considerations 10. IANA Considerations
Note to RFC Editor: please replace "This RFC" throughout this Note to RFC Editor: please replace "This RFC" throughout this
document by the RFC number for this specification once it is document by the RFC number for this specification once it is
attributed. attributed.
IANA is requested to make a number of changes under the "Internet IANA is requested to make a number of changes under the "Internet
skipping to change at page 25, line 5 skipping to change at page 23, line 38
Table 2: new ARO Flags Table 2: new ARO Flags
10.2. ICMP Codes 10.2. ICMP Codes
IANA is requested to create a new entry in the ICMPv6 "Code" Fields IANA is requested to create a new entry in the ICMPv6 "Code" Fields
subregistry of the Internet Control Message Protocol version 6 subregistry of the Internet Control Message Protocol version 6
(ICMPv6) Parameters for the ICMP codes related to the ICMP type 157 (ICMPv6) Parameters for the ICMP codes related to the ICMP type 157
and 158 Duplicate Address Request (shown in Table 3) and Confirmation and 158 Duplicate Address Request (shown in Table 3) and Confirmation
(shown in Table 4), respectively, as follows: (shown in Table 4), respectively, as follows:
Internet-Draft An Update to 6LoWPAN ND February
New entries for ICMP types 157 DAR message New entries for ICMP types 157 DAR message
+-------+----------------------+------------+ +-------+----------------------+------------+
| Code | Name | Reference | | Code | Name | Reference |
+-------+----------------------+------------+ +-------+----------------------+------------+
| 0 | Original DAR message | RFC 6775 | | 0 | Original DAR message | RFC 6775 |
| | | | | | | |
| 1 | Extended DAR message | This RFC | | 1 | Extended DAR message | This RFC |
+-------+----------------------+------------+ +-------+----------------------+------------+
skipping to change at page 26, line 5 skipping to change at page 24, line 22
| 1 | Extended DAC message | This RFC | | 1 | Extended DAC message | This RFC |
+-------+----------------------+------------+ +-------+----------------------+------------+
Table 4: new ICMPv6 Code Fields Table 4: new ICMPv6 Code Fields
10.3. New ARO Status values 10.3. New ARO Status values
IANA is requested to make additions to the Address Registration IANA is requested to make additions to the Address Registration
Option Status Values Registry as follows: Option Status Values Registry as follows:
Internet-Draft An Update to 6LoWPAN ND February
Address Registration Option Status Values Registry Address Registration Option Status Values Registry
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| ARO Status | Description | Document | | ARO Status | Description | Document |
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| 3 | Moved | This RFC | | 3 | Moved | This RFC |
| | | | | | | |
| 4 | Removed | This RFC | | 4 | Removed | This RFC |
| | | | | | | |
| 5 | Validation Requested | This RFC | | 5 | Validation Requested | This RFC |
skipping to change at page 27, line 5 skipping to change at page 25, line 22
| | | | | | | |
| 12 | 6LBR capable (B bit) | This RFC | | 12 | 6LBR capable (B bit) | This RFC |
| | | | | | | |
| 13 | 6BBR capable (P bit) | This RFC | | 13 | 6BBR capable (P bit) | This RFC |
| | | | | | | |
| 14 | EARO support (E bit) | This RFC | | 14 | EARO support (E bit) | This RFC |
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
Table 6: New 6LoWPAN capability Bits Table 6: New 6LoWPAN capability Bits
Internet-Draft An Update to 6LoWPAN ND February
11. Acknowledgments 11. Acknowledgments
Kudos to Eric Levy-Abegnoli who designed the First Hop Security Kudos to Eric Levy-Abegnoli who designed the First Hop Security
infrastructure upon which the first backbone router was implemented. infrastructure upon which the first backbone router was implemented.
Many thanks to Sedat Gormus, Rahul Jadhav and Lorenzo Colitti for Many thanks to Sedat Gormus, Rahul Jadhav, Tim Chown, Juergen
their various contributions and reviews. Also many thanks to Thomas Schoenwaelder, Chris Lonvick and Lorenzo Colitti for their various
Watteyne for his early implementation of a 6LN that was instrumental contributions and reviews. Also many thanks to Thomas Watteyne for
to the early tests of the 6LR, 6LBR and Backbone Router. his early implementation of a 6LN that was instrumental to the early
tests of the 6LR, 6LBR and Backbone Router.
12. References 12. References
12.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 28, line 5 skipping to change at page 26, line 26
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011, DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>. <https://www.rfc-editor.org/info/rfc6282>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)", Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012, RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>. <https://www.rfc-editor.org/info/rfc6775>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for [RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>. 2014, <https://www.rfc-editor.org/info/rfc7400>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
skipping to change at page 29, line 5 skipping to change at page 27, line 31
[I-D.ietf-6tisch-architecture] [I-D.ietf-6tisch-architecture]
Thubert, P., "An Architecture for IPv6 over the TSCH mode Thubert, P., "An Architecture for IPv6 over the TSCH mode
of IEEE 802.15.4", draft-ietf-6tisch-architecture-13 (work of IEEE 802.15.4", draft-ietf-6tisch-architecture-13 (work
in progress), November 2017. in progress), November 2017.
[I-D.ietf-ipv6-multilink-subnets] [I-D.ietf-ipv6-multilink-subnets]
Thaler, D. and C. Huitema, "Multi-link Subnet Support in Thaler, D. and C. Huitema, "Multi-link Subnet Support in
IPv6", draft-ietf-ipv6-multilink-subnets-00 (work in IPv6", draft-ietf-ipv6-multilink-subnets-00 (work in
progress), July 2002. progress), July 2002.
Internet-Draft An Update to 6LoWPAN ND February
[I-D.ietf-mboned-ieee802-mcast-problems] [I-D.ietf-mboned-ieee802-mcast-problems]
Perkins, C., McBride, M., Stanley, D., Kumari, W., and J. Perkins, C., McBride, M., Stanley, D., Kumari, W., and J.
Zuniga, "Multicast Considerations over IEEE 802 Wireless Zuniga, "Multicast Considerations over IEEE 802 Wireless
Media", draft-ietf-mboned-ieee802-mcast-problems-01 (work Media", draft-ietf-mboned-ieee802-mcast-problems-01 (work
in progress), February 2018. in progress), February 2018.
[I-D.perkins-intarea-multicast-ieee802] [I-D.perkins-intarea-multicast-ieee802]
Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,
"Multicast Considerations over IEEE 802 Wireless Media", "Multicast Considerations over IEEE 802 Wireless Media",
draft-perkins-intarea-multicast-ieee802-03 (work in draft-perkins-intarea-multicast-ieee802-03 (work in
skipping to change at page 29, line 30 skipping to change at page 28, line 5
Popa, D. and J. Hui, "6LoPLC: Transmission of IPv6 Packets Popa, D. and J. Hui, "6LoPLC: Transmission of IPv6 Packets
over IEEE 1901.2 Narrowband Powerline Communication over IEEE 1901.2 Narrowband Powerline Communication
Networks", draft-popa-6lo-6loplc-ipv6-over- Networks", draft-popa-6lo-6loplc-ipv6-over-
ieee19012-networks-00 (work in progress), March 2014. ieee19012-networks-00 (work in progress), March 2014.
[I-D.struik-lwip-curve-representations] [I-D.struik-lwip-curve-representations]
Struik, R., "Alternative Elliptic Curve Representations", Struik, R., "Alternative Elliptic Curve Representations",
draft-struik-lwip-curve-representations-00 (work in draft-struik-lwip-curve-representations-00 (work in
progress), October 2017. progress), October 2017.
[RFC1558] Howes, T., "A String Representation of LDAP Search
Filters", RFC 1558, DOI 10.17487/RFC1558, December 1993,
<https://www.rfc-editor.org/info/rfc1558>.
[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
DOI 10.17487/RFC1982, August 1996, DOI 10.17487/RFC1982, August 1996,
<https://www.rfc-editor.org/info/rfc1982>. <https://www.rfc-editor.org/info/rfc1982>.
[RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with [RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with
CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September
2003, <https://www.rfc-editor.org/info/rfc3610>. 2003, <https://www.rfc-editor.org/info/rfc3610>.
[RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener [RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener
Discovery Version 2 (MLDv2) for IPv6", RFC 3810, Discovery Version 2 (MLDv2) for IPv6", RFC 3810,
skipping to change at page 30, line 5 skipping to change at page 28, line 35
<https://www.rfc-editor.org/info/rfc3971>. <https://www.rfc-editor.org/info/rfc3971>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005, RFC 3972, DOI 10.17487/RFC3972, March 2005,
<https://www.rfc-editor.org/info/rfc3972>. <https://www.rfc-editor.org/info/rfc3972>.
[RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD) [RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD)
for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006, for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006,
<https://www.rfc-editor.org/info/rfc4429>. <https://www.rfc-editor.org/info/rfc4429>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6 [RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs): over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals", Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007, RFC 4919, DOI 10.17487/RFC4919, August 2007,
<https://www.rfc-editor.org/info/rfc4919>. <https://www.rfc-editor.org/info/rfc4919>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007, IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<https://www.rfc-editor.org/info/rfc4941>. <https://www.rfc-editor.org/info/rfc4941>.
skipping to change at page 31, line 5 skipping to change at page 29, line 36
[RFC7428] Brandt, A. and J. Buron, "Transmission of IPv6 Packets [RFC7428] Brandt, A. and J. Buron, "Transmission of IPv6 Packets
over ITU-T G.9959 Networks", RFC 7428, over ITU-T G.9959 Networks", RFC 7428,
DOI 10.17487/RFC7428, February 2015, DOI 10.17487/RFC7428, February 2015,
<https://www.rfc-editor.org/info/rfc7428>. <https://www.rfc-editor.org/info/rfc7428>.
[RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B., [RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B.,
Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low
Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015, Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015,
<https://www.rfc-editor.org/info/rfc7668>. <https://www.rfc-editor.org/info/rfc7668>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi, [RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi,
"Host Address Availability Recommendations", BCP 204, "Host Address Availability Recommendations", BCP 204,
RFC 7934, DOI 10.17487/RFC7934, July 2016, RFC 7934, DOI 10.17487/RFC7934, July 2016,
<https://www.rfc-editor.org/info/rfc7934>. <https://www.rfc-editor.org/info/rfc7934>.
[RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu,
"Recommendation on Stable IPv6 Interface Identifiers", "Recommendation on Stable IPv6 Interface Identifiers",
RFC 8064, DOI 10.17487/RFC8064, February 2017, RFC 8064, DOI 10.17487/RFC8064, February 2017,
<https://www.rfc-editor.org/info/rfc8064>. <https://www.rfc-editor.org/info/rfc8064>.
skipping to change at page 32, line 5 skipping to change at page 30, line 36
IEEE Standard 802.15.4, DOI 10.1109/IEEE IEEE Standard 802.15.4, DOI 10.1109/IEEE
P802.15.4-REVd/D01, June 2017, P802.15.4-REVd/D01, June 2017,
<http://ieeexplore.ieee.org/document/7460875/>. <http://ieeexplore.ieee.org/document/7460875/>.
[Perlman83] [Perlman83]
Perlman, R., "Fault-Tolerant Broadcast of Routing Perlman, R., "Fault-Tolerant Broadcast of Routing
Information", North-Holland Computer Networks 7: 395-405, Information", North-Holland Computer Networks 7: 395-405,
1983, <http://www.cs.illinois.edu/~pbg/courses/cs598fa09/ 1983, <http://www.cs.illinois.edu/~pbg/courses/cs598fa09/
readings/p83.pdf>. readings/p83.pdf>.
Internet-Draft An Update to 6LoWPAN ND February
Appendix A. Applicability and Requirements Served Appendix A. Applicability and Requirements Served
This specification extends 6LoWPAN ND to provide a sequence number to This specification extends 6LoWPAN ND to provide a sequence number to
the registration and serves the requirements expressed Appendix B.1 the registration and serves the requirements expressed Appendix B.1
by enabling the mobility of devices from one LLN to the next based on by enabling the mobility of devices from one LLN to the next based on
the complementary work in the "IPv6 Backbone Router" the complementary work in the "IPv6 Backbone Router"
[I-D.ietf-6lo-backbone-router] specification. [I-D.ietf-6lo-backbone-router] specification.
In the context of the the TimeSlotted Channel Hopping (TSCH) mode of In the context of the the TimeSlotted Channel Hopping (TSCH) mode of
IEEE Std. 802.15.4 [IEEEstd802154], the "6TiSCH architecture" IEEE Std. 802.15.4 [IEEEstd802154], the "6TiSCH architecture"
skipping to change at page 32, line 32 skipping to change at page 31, line 12
implement the 6TiSCH architecture and serves the requirements listed implement the 6TiSCH architecture and serves the requirements listed
in Appendix B.2. in Appendix B.2.
The term LLN is used loosely in this specification to cover multiple The term LLN is used loosely in this specification to cover multiple
types of WLANs and WPANs, including Low-Power Wi-Fi, BLUETOOTH(R) Low types of WLANs and WPANs, including Low-Power Wi-Fi, BLUETOOTH(R) Low
Energy, IEEE Std.802.11AH and IEEE Std.802.15.4 wireless meshes, so Energy, IEEE Std.802.11AH and IEEE Std.802.15.4 wireless meshes, so
as to address the requirements discussed in Appendix B.3. as to address the requirements discussed in Appendix B.3.
This specification can be used by any wireless node to associate at This specification can be used by any wireless node to associate at
Layer-3 with a 6BBR and register its IPv6 addresses to obtain routing Layer-3 with a 6BBR and register its IPv6 addresses to obtain routing
services including proxy-ND operations over the Backbone, effectively services including proxy-ND operations over a Backbone Link,
providing a solution to the requirements expressed in Appendix B.4. effectively providing a solution to the requirements expressed in
Appendix B.4.
This specification is extended by "Address Protected Neighbor This specification is extended by "Address Protected Neighbor
Discovery for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd] to Discovery for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd] to
providing a solution to some of the security-related requirements providing a solution to some of the security-related requirements
expressed in Appendix B.5. expressed in Appendix B.5.
"Efficiency aware IPv6 Neighbor Discovery Optimizations" "Efficiency aware IPv6 Neighbor Discovery Optimizations"
[I-D.chakrabarti-nordmark-6man-efficient-nd] suggests that 6LoWPAN ND [I-D.chakrabarti-nordmark-6man-efficient-nd] suggests that 6LoWPAN ND
[RFC6775] can be extended to other types of links beyond IEEE Std. [RFC6775] can be extended to other types of links beyond IEEE Std.
802.15.4 for which it was defined. The registration technique is 802.15.4 for which it was defined. The registration technique is
skipping to change at page 33, line 5 skipping to change at page 31, line 36
packets is not sufficiently efficient in terms of delivery ratio or packets is not sufficiently efficient in terms of delivery ratio or
energy consumption in the end devices, in particular to enable energy consumption in the end devices, in particular to enable
energy-constrained sleeping nodes. The value of such extension is energy-constrained sleeping nodes. The value of such extension is
especially apparent in the case of mobile wireless nodes, to reduce especially apparent in the case of mobile wireless nodes, to reduce
the multicast operations that are related to IPv6 ND ([RFC4861], the multicast operations that are related to IPv6 ND ([RFC4861],
[RFC4862]) and affect the operation of the wireless medium [RFC4862]) and affect the operation of the wireless medium
[I-D.ietf-mboned-ieee802-mcast-problems] [I-D.ietf-mboned-ieee802-mcast-problems]
[I-D.perkins-intarea-multicast-ieee802]. This serves the scalability [I-D.perkins-intarea-multicast-ieee802]. This serves the scalability
requirements listed in Appendix B.6. requirements listed in Appendix B.6.
Internet-Draft An Update to 6LoWPAN ND February Finally Appendix B.8 provides a matching of requirements with the
Finally Appendix B.7 provides a matching of requirements with the
specifications that serves them. specifications that serves them.
Appendix B. Requirements Appendix B. Requirements
This section lists requirements that were discussed at 6lo for an This section lists requirements that were discussed at 6lo for an
update to 6LoWPAN ND. This specification meets most of them, but update to 6LoWPAN ND. This specification meets most of them, but
those listed in Appendix B.5 which are deferred to a different those listed in Appendix B.5 which are deferred to a different
specification such as [I-D.ietf-6lo-ap-nd], and those related to specification such as [I-D.ietf-6lo-ap-nd], and those related to
multicast. multicast.
skipping to change at page 34, line 4 skipping to change at page 32, line 34
that was defined at the IETF for this particular purpose. Other that was defined at the IETF for this particular purpose. Other
routing protocols than RPL are also considered by Standard Defining routing protocols than RPL are also considered by Standard Defining
Organizations (SDO) on the basis of the expected network Organizations (SDO) on the basis of the expected network
characteristics. It is required that a 6LoWPAN Node attached via ND characteristics. It is required that a 6LoWPAN Node attached via ND
to a 6LR would need to participate in the selected routing protocol to a 6LR would need to participate in the selected routing protocol
to obtain reachability via the 6LR. to obtain reachability via the 6LR.
Next to the 6LBR unicast address registered by ND, other addresses Next to the 6LBR unicast address registered by ND, other addresses
including multicast addresses are needed as well. For example a including multicast addresses are needed as well. For example a
routing protocol often uses a multicast address to register changes routing protocol often uses a multicast address to register changes
Internet-Draft An Update to 6LoWPAN ND February
to established paths. ND needs to register such a multicast address to established paths. ND needs to register such a multicast address
to enable routing concurrently with discovery. to enable routing concurrently with discovery.
Multicast is needed for groups. Groups may be formed by device type Multicast is needed for groups. Groups may be formed by device type
(e.g. routers, street lamps), location (Geography, RPL sub-tree), or (e.g. routers, street lamps), location (Geography, RPL sub-tree), or
both. both.
The Bit Index Explicit Replication (BIER) Architecture [RFC8279] The Bit Index Explicit Replication (BIER) Architecture [RFC8279]
proposes an optimized technique to enable multicast in a LLN with a proposes an optimized technique to enable multicast in a LLN with a
very limited requirement for routing state in the nodes. very limited requirement for routing state in the nodes.
skipping to change at page 35, line 4 skipping to change at page 33, line 35
Communication [I-D.ietf-6lo-nfc], IEEE Std. 802.11ah Communication [I-D.ietf-6lo-nfc], IEEE Std. 802.11ah
[I-D.delcarpio-6lo-wlanah], as well as IEEE1901.2 Narrowband [I-D.delcarpio-6lo-wlanah], as well as IEEE1901.2 Narrowband
Powerline Communication Networks Powerline Communication Networks
[I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks] and BLUETOOTH(R) [I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks] and BLUETOOTH(R)
Low Energy [RFC7668]. Low Energy [RFC7668].
Related requirements are: Related requirements are:
Req3.1: The support of the registration mechanism SHOULD be extended Req3.1: The support of the registration mechanism SHOULD be extended
to more LLN links than IEEE Std.802.15.4, matching at least the LLN to more LLN links than IEEE Std.802.15.4, matching at least the LLN
Internet-Draft An Update to 6LoWPAN ND February
links for which an "IPv6 over foo" specification exists, as well as links for which an "IPv6 over foo" specification exists, as well as
Low-Power Wi-Fi. Low-Power Wi-Fi.
Req3.2: As part of this extension, a mechanism to compute a unique Req3.2: As part of this extension, a mechanism to compute a unique
Identifier should be provided, with the capability to form a Link- Identifier should be provided, with the capability to form a Link-
Local Address that SHOULD be unique at least within the LLN connected Local Address that SHOULD be unique at least within the LLN connected
to a 6LBR discovered by ND in each node within the LLN. to a 6LBR discovered by ND in each node within the LLN.
Req3.3: The Address Registration Option used in the ND registration Req3.3: The Address Registration Option used in the ND registration
SHOULD be extended to carry the relevant forms of unique Identifier. SHOULD be extended to carry the relevant forms of unique Identifier.
Req3.4: The Neighbour Discovery should specify the formation of a Req3.4: The Neighbour Discovery should specify the formation of a
site-local address that follows the security recommendations from site-local address that follows the security recommendations from
[RFC7217]. [RFC7217].
B.4. Requirements Related to Proxy Operations B.4. Requirements Related to Proxy Operations
Duty-cycled devices may not be able to answer themselves to a lookup Duty-cycled devices may not be able to answer themselves to a lookup
from a node that uses IPv6 ND on a Backbone and may need a proxy. from a node that uses IPv6 ND on a Backbone Link and may need a
Additionally, the duty-cycled device may need to rely on the 6LBR to proxy. Additionally, the duty-cycled device may need to rely on the
perform registration to the 6BBR. 6LBR to perform registration to the 6BBR.
The ND registration method SHOULD defend the addresses of duty-cycled The ND registration method SHOULD defend the addresses of duty-cycled
devices that are sleeping most of the time and not capable to defend devices that are sleeping most of the time and not capable to defend
their own Addresses. their own Addresses.
Related requirements are: Related requirements are:
Req4.1: The registration mechanism SHOULD enable a third party to Req4.1: The registration mechanism SHOULD enable a third party to
proxy register an Address on behalf of a 6LoWPAN node that may be proxy register an Address on behalf of a 6LoWPAN node that may be
sleeping or located deeper in an LLN mesh. sleeping or located deeper in an LLN mesh.
skipping to change at page 36, line 5 skipping to change at page 34, line 37
durations, in the order of multiple days to a month. durations, in the order of multiple days to a month.
B.5. Requirements Related to Security B.5. Requirements Related to Security
In order to guarantee the operations of the 6LoWPAN ND flows, the In order to guarantee the operations of the 6LoWPAN ND flows, the
spoofing of the 6LR, 6LBR and 6BBRs roles should be avoided. Once a spoofing of the 6LR, 6LBR and 6BBRs roles should be avoided. Once a
node successfully registers an address, 6LoWPAN ND should provide node successfully registers an address, 6LoWPAN ND should provide
energy-efficient means for the 6LBR to protect that ownership even energy-efficient means for the 6LBR to protect that ownership even
when the node that registered the address is sleeping. when the node that registered the address is sleeping.
Internet-Draft An Update to 6LoWPAN ND February
In particular, the 6LR and the 6LBR then should be able to verify In particular, the 6LR and the 6LBR then should be able to verify
whether a subsequent registration for a given address comes from the whether a subsequent registration for a given address comes from the
original node. original node.
In a LLN it makes sense to base security on layer-2 security. During In a LLN it makes sense to base security on layer-2 security. During
bootstrap of the LLN, nodes join the network after authorization by a bootstrap of the LLN, nodes join the network after authorization by a
Joining Assistant (JA) or a Commissioning Tool (CT). After joining Joining Assistant (JA) or a Commissioning Tool (CT). After joining
nodes communicate with each other via secured links. The keys for nodes communicate with each other via secured links. The keys for
the layer-2 security are distributed by the JA/CT. The JA/CT can be the layer-2 security are distributed by the JA/CT. The JA/CT can be
part of the LLN or be outside the LLN. In both cases it is needed part of the LLN or be outside the LLN. In both cases it is needed
skipping to change at page 37, line 5 skipping to change at page 35, line 37
present on the device for upper layer security such as TLS. present on the device for upper layer security such as TLS.
Req5.7: Public key and signature sizes SHOULD be minimized while Req5.7: Public key and signature sizes SHOULD be minimized while
maintaining adequate confidentiality and data origin authentication maintaining adequate confidentiality and data origin authentication
for multiple types of applications with various degrees of for multiple types of applications with various degrees of
criticality. criticality.
Req5.8: Routing of packets should continue when links pass from the Req5.8: Routing of packets should continue when links pass from the
unsecured to the secured state. unsecured to the secured state.
Internet-Draft An Update to 6LoWPAN ND February
Req5.9: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for Req5.9: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for
the 6LR and the 6LBR to validate whether a new registration for a the 6LR and the 6LBR to validate whether a new registration for a
given address corresponds to the same 6LoWPAN Node that registered it given address corresponds to the same 6LoWPAN Node that registered it
initially, and, if not, determine the rightful owner, and deny or initially, and, if not, determine the rightful owner, and deny or
clean-up the registration that is duplicate. clean-up the registration that is duplicate.
B.6. Requirements Related to Scalability B.6. Requirements Related to Scalability
Use cases from Automatic Meter Reading (AMR, collection tree Use cases from Automatic Meter Reading (AMR, collection tree
operations) and Advanced Metering Infrastructure (AMI, bi-directional operations) and Advanced Metering Infrastructure (AMI, bi-directional
skipping to change at page 37, line 29 skipping to change at page 36, line 11
to the 6LBR over a large number of LLN hops (e.g. 15). to the 6LBR over a large number of LLN hops (e.g. 15).
Related requirements are: Related requirements are:
Req6.1: The registration mechanism SHOULD enable a single 6LBR to Req6.1: The registration mechanism SHOULD enable a single 6LBR to
register multiple thousands of devices. register multiple thousands of devices.
Req6.2: The timing of the registration operation should allow for a Req6.2: The timing of the registration operation should allow for a
large latency such as found in LLNs with ten and more hops. large latency such as found in LLNs with ten and more hops.
B.7. Matching Requirements with Specifications B.7. Requirements Related to Operations and Management
Section 3.8 of "Architectural Principles of the Internet" [RFC1558]
recommends to : "avoid options and parameters whenever possible. Any
options and parameters should be configured or negotiated dynamically
rather than manually". This is especially true in LLNs where the
number of devices may be large and manual configuration is
infeasible. Capabilities for a dynamic configuration of LLN devices
can also be constrained by the network and power limitation.
A Network Administrator should be able to validate that the network
is operating within capacity, and that in particular a 6LBR does not
get overloaded with an excessive amount of registration, so he can
take actions such as adding a Backbone Link with additional 6LBRs and
6BBRs to his network.
Related requirements are:
Req7.1: A management model SHOULD be provided providing access to the
6LBR and its capacity. It is recommended that the 6LBR be reachable
over a non-LLN link.
Req7.2: A management model SHOULD be provided providing access to the
6LR and its capacity to host additional NCE. This management model
SHOULD avoid polling individual 6LRs n a way that could disrupt the
operation of the LLN.
Req7.3: information on successful and failed registration SHOULD be
provided, including information such as the RUID of the 6LN, the
Registered Address, the Address of the 6LR and the duration of the
registration flow.
Req7.4: In case of a failed registration, information on the failure
including the identification of the node that rejected the
registration and the status in the EARO SHOULD be provided
B.8. Matching Requirements with Specifications
I-drafts/RFCs addressing requirements I-drafts/RFCs addressing requirements
+-------------+-----------------------------------------+ +-------------+-----------------------------------------+
| Requirement | Document | | Requirement | Document |
+-------------+-----------------------------------------+ +-------------+-----------------------------------------+
| Req1.1 | [I-D.ietf-6lo-backbone-router] | | Req1.1 | [I-D.ietf-6lo-backbone-router] |
| | | | | |
| Req1.2 | [RFC6775] | | Req1.2 | [RFC6775] |
| | | | | |
skipping to change at page 38, line 4 skipping to change at page 37, line 24
| | | | | |
| Req2.2 | This RFC | | Req2.2 | This RFC |
| | | | | |
| Req2.3 | | | Req2.3 | |
| | | | | |
| Req3.1 | Technology Dependant | | Req3.1 | Technology Dependant |
| | | | | |
| Req3.2 | Technology Dependant | | Req3.2 | Technology Dependant |
| | | | | |
| Req3.3 | Technology Dependant | | Req3.3 | Technology Dependant |
Internet-Draft An Update to 6LoWPAN ND February
| | | | | |
| Req3.4 | Technology Dependant | | Req3.4 | Technology Dependant |
| | | | | |
| Req4.1 | This RFC | | Req4.1 | This RFC |
| | | | | |
| Req4.2 | This RFC | | Req4.2 | This RFC |
| | | | | |
| Req4.3 | [RFC6775] | | Req4.3 | [RFC6775] |
| | | | | |
| Req5.1 | | | Req5.1 | |
skipping to change at page 38, line 37 skipping to change at page 38, line 6
| | | | | |
| Req5.7 | [I-D.ietf-6lo-ap-nd] | | Req5.7 | [I-D.ietf-6lo-ap-nd] |
| | | | | |
| Req5.8 | | | Req5.8 | |
| | | | | |
| Req5.9 | [I-D.ietf-6lo-ap-nd] | | Req5.9 | [I-D.ietf-6lo-ap-nd] |
| | | | | |
| Req6.1 | This RFC | | Req6.1 | This RFC |
| | | | | |
| Req6.2 | This RFC | | Req6.2 | This RFC |
| | |
| Req7.1 | |
| | |
| Req7.2 | |
| | |
| Req7.3 | |
| | |
| Req7.4 | |
+-------------+-----------------------------------------+ +-------------+-----------------------------------------+
Table 7: Addressing requirements Table 7: Work Addressing requirements
Appendix C. Subset of a 6LoWPAN Glossary Appendix C. Subset of a 6LoWPAN Glossary
This document often uses the followng acronyms: This document often uses the followng acronyms:
6BBR: 6LoWPAN Backbone Router (proxy for the registration) 6BBR: 6LoWPAN Backbone Router (proxy for the registration)
6LBR: 6LoWPAN Border Router (authoritative on DAD) 6LBR: 6LoWPAN Border Router (authoritative on DAD)
6LN: 6LoWPAN Node 6LN: 6LoWPAN Node
6LR: 6LoWPAN Router (relay to the registration process) 6LR: 6LoWPAN Router (relay to the registration process)
6CIO: Capability Indication Option 6CIO: Capability Indication Option
Internet-Draft An Update to 6LoWPAN ND February
(E)ARO: (Extended) Address Registration Option (E)ARO: (Extended) Address Registration Option
DAD: Duplicate Address Detection DAD: Duplicate Address Detection
LLN: Low Power Lossy Network (a typical IoT network) LLN: Low Power Lossy Network (a typical IoT network)
NCE: Neighbor Cache Entry NCE: Neighbor Cache Entry
RUID: Registration Unique ID
TSCH: TimeSlotted Channel Hopping TSCH: TimeSlotted Channel Hopping
TID: Transaction ID (a sequence counter in the EARO) TID: Transaction ID (a sequence counter in the EARO)
Authors' Addresses Authors' Addresses
Pascal Thubert (editor) Pascal Thubert (editor)
Cisco Systems, Inc Cisco Systems, Inc
Building D (Regus) 45 Allee des Ormes Building D (Regus) 45 Allee des Ormes
Mougins - Sophia Antipolis Mougins - Sophia Antipolis
France France
 End of changes. 120 change blocks. 
316 lines changed or deleted 235 lines changed or added

This html diff was produced by rfcdiff 1.46. The latest version is available from http://tools.ietf.org/tools/rfcdiff/