draft-ietf-softwire-dslite-yang-17.txt   rfc8513.txt 
Network Working Group M. Boucadair Internet Engineering Task Force (IETF) M. Boucadair
Internet-Draft C. Jacquenet Request for Comments: 8513 C. Jacquenet
Intended status: Standards Track Orange Category: Standards Track Orange
Expires: November 30, 2018 S. Sivakumar ISSN: 2070-1721 S. Sivakumar
Cisco Systems Cisco Systems
May 29, 2018 January 2019
A YANG Data Model for Dual-Stack Lite (DS-Lite) A YANG Data Model for Dual-Stack Lite (DS-Lite)
draft-ietf-softwire-dslite-yang-17
Abstract Abstract
This document defines a YANG module for the DS-Lite Address Family This document defines a YANG module for the Dual-Stack Lite (DS-Lite)
Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements. Address Family Transition Router (AFTR) and Basic Bridging BroadBand
(B4) elements.
Editorial Note (To be removed by RFC Editor)
Please update these statements in the document with the RFC number to
be assigned to this document:
o "This version of this YANG module is part of RFC XXXX;"
o "RFC XXXX: A YANG Data Model for Dual-Stack Lite (DS-Lite)";
o "reference: RFC XXXX"
Please update the "revision" date of the YANG module.
Also, update this sentence with the RFC number to be assigned to I-
D.ietf-opsawg-nat-yang:
o "RFC YYYY: A YANG Module for Network Address Translation (NAT) and
Network Prefix Translation (NPT)"
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on November 30, 2018. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8513.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2019 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
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. DS-Lite YANG Module: An Overview . . . . . . . . . . . . . . 4 2. DS-Lite YANG Module: An Overview . . . . . . . . . . . . . . 4
3. DS-Lite YANG Module . . . . . . . . . . . . . . . . . . . . . 6 3. DS-Lite YANG Module . . . . . . . . . . . . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . 15 4. Security Considerations . . . . . . . . . . . . . . . . . . . 15
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 6.1. Normative References . . . . . . . . . . . . . . . . . . 16
7.1. Normative references . . . . . . . . . . . . . . . . . . 16 6.2. Informative References . . . . . . . . . . . . . . . . . 17
7.2. Informative references . . . . . . . . . . . . . . . . . 17
Appendix A. B4 Example . . . . . . . . . . . . . . . . . . . . . 19 Appendix A. B4 Example . . . . . . . . . . . . . . . . . . . . . 19
Appendix B. AFTR Examples . . . . . . . . . . . . . . . . . . . 19 Appendix B. AFTR Examples . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction 1. Introduction
This document defines a data model for DS-Lite [RFC6333], using the This document defines a data model for DS-Lite [RFC6333], using the
YANG data modeling language [RFC7950]. Both the Address Family YANG data modeling language [RFC7950]. Both the Address Family
Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements
are covered by this specification. are covered by this specification.
As a reminder, Figure 1 illustrates an overview of the DS-Lite Figure 1 is a slight adaptation of Figure 1 from RFC 6333 and is
architecture that involves AFTR and B4 elements. provided here for the convenience of the reader.
+-----------+ +-----------+
| Host | | Host |
+-----+-----+ +-----+-----+
|192.0.2.1 |192.0.2.1
| |
| |
|192.0.2.2 |192.0.2.2
+---------|---------+ +---------|---------+
| | | | | |
| Home router | | Home router |
|+--------+--------+| |+--------+--------+|
|| B4 || || B4 ||
|+--------+--------+| |+--------+--------+|
+--------|||--------+ +--------|||--------+
|||2001:db8:0:1::1 |||2001:db8:0:1::1
||| |||
|||<-IPv4-in-IPv6 softwire |||<-IPv4-in-IPv6 Softwire
||| |||
-------|||------- -------|||-------
/ ||| \ / ||| \
| ISP core network | | ISP core network |
\ ||| / \ ||| /
-------|||------- -------|||-------
||| |||
|||2001:db8:0:2::1 |||2001:db8:0:2::1
+--------|||--------+ +--------|||--------+
| AFTR | | AFTR |
skipping to change at page 4, line 7 skipping to change at page 4, line 7
| |
|203.0.113.1 |203.0.113.1
+-----+-----+ +-----+-----+
| IPv4 Host | | IPv4 Host |
+-----------+ +-----------+
Figure 1: DS-Lite Base Architecture Figure 1: DS-Lite Base Architecture
DS-Lite deployment considerations are discussed in [RFC6908]. DS-Lite deployment considerations are discussed in [RFC6908].
This document follows the guidelines of [RFC6087], uses the common This document follows the guidelines of [RFC8407], uses the common
YANG types defined in [RFC6991], and adopts the Network Management YANG types defined in [RFC6991], and adopts the Network Management
Datastore Architecture (NMDA). Datastore Architecture (NMDA) [RFC8342].
1.1. Terminology 1.1. Terminology
This document makes use of the terms defined in Section 3 of This document makes use of the terms defined in Section 3 of
[RFC6333]. [RFC6333].
The terminology for describing YANG data models is defined in The terminology for describing YANG data models is defined in
[RFC7950]. [RFC7950].
The meaning of the symbols in tree diagrams is defined in [RFC8340]. The meaning of the symbols in tree diagrams is defined in [RFC8340].
skipping to change at page 4, line 31 skipping to change at page 4, line 31
2. DS-Lite YANG Module: An Overview 2. DS-Lite YANG Module: An Overview
As shown in Figure 1: As shown in Figure 1:
o The AFTR element is a combination of an IPv4-in-IPv6 tunnel and a o The AFTR element is a combination of an IPv4-in-IPv6 tunnel and a
NAPT function (Section 2.2 of [RFC3022]). NAPT function (Section 2.2 of [RFC3022]).
o The B4 element is an IPv4-in-IPv6 tunnel. o The B4 element is an IPv4-in-IPv6 tunnel.
Therefore, the DS-Lite YANG module is designed to augment both the Therefore, the DS-Lite YANG module is designed to augment both the
Interfaces YANG module [RFC8343] and the NAT YANG module Interfaces YANG module [RFC8343] and the NAT YANG module [RFC8512]
[I-D.ietf-opsawg-nat-yang] with DS-Lite specific features. with DS-Lite-specific features.
The YANG "feature" statement is used to distinguish which of the DS- The YANG "feature" statement is used to distinguish which of the
Lite elements ('aftr' or 'b4') is relevant for a specific data node. DS-Lite elements ('aftr' or 'b4') is relevant for a specific data
node.
Concretely, the DS-Lite YANG module (Figure 2) augments the Concretely, the DS-Lite YANG module (Figure 2) augments the
Interfaces YANG module with the following: Interfaces YANG module with the following:
o An IPv6 address used by the tunnel endpoint (AFTR or B4) for o An IPv6 address used by the tunnel endpoint (AFTR or B4) for
sending and receiving IPv4-in-IPv6 packets (ipv6-address). sending and receiving IPv4-in-IPv6 packets (ipv6-address).
o An IPv4 address that is used by the tunnel endpoint (AFTR or B4) o An IPv4 address that is used by the tunnel endpoint (AFTR or B4)
for troubleshooting purposes (ipv4-address). for troubleshooting purposes (ipv4-address).
o An IPv6 address used by a B4 element to reach its AFTR (aftr- o An IPv6 address used by a B4 element to reach its AFTR (aftr-
ipv6-addr). ipv6-addr).
o The tunnel MTU used to avoid fragmentation (tunnel-mtu). o The tunnel MTU used to avoid fragmentation (tunnel-mtu).
o A policy to instruct the tunnel endpoint (AFTR or B4) whether it o A policy to instruct the tunnel endpoint (AFTR or B4) whether it
must preserve DSCP marking when encapsulating/decapsulating must preserve Differentiated Services Code Point (DSCP) marking
packets (v6-v4-dscp-preservation). when encapsulating/decapsulating packets (v6-v4-dscp-
preservation).
In addition, the DS-Lite YANG module augments the NAT YANG module In addition, the DS-Lite YANG module augments the NAT YANG module
(policy, in particular) with the following: (policy, in particular) with the following:
o A policy to limit the number of DS-Lite softwires per subscriber o A policy to limit the number of DS-Lite softwires per subscriber
(max-softwire-per-subscriber). (max-softwire-per-subscriber).
o A policy to instruct the AFTR whether a state can be automatically o A policy to instruct the AFTR whether a state can be automatically
migrated (state-migrate). migrated (state-migrate).
o Further, in order to prevent a denial-of-service by frequently o Further, in order to prevent a Denial of Service (DoS) by
changing the source IPv6 address, 'b4-address-change-limit' is frequently changing the source IPv6 address, 'b4-address-change-
used to rate-limit such changes. limit' is used to rate-limit such changes.
o An instruction to rewrite the TCP Maximum Segment Size (MSS) o An instruction to rewrite the TCP Maximum Segment Size (MSS)
option (mss-clamping) to avoid TCP fragmentation. option (mss-clamping) to avoid TCP fragmentation.
Given that the NAPT table of the AFTR element is extended to include Given that the NAPT table of the AFTR element is extended to include
the source IPv6 address of incoming packets, the DS-Lite YANG module the source IPv6 address of incoming packets, the DS-Lite YANG module
augments the NAPT44 mapping-entry with the following: augments the NAPT44 mapping entry with the following:
o b4-ipv6-address which is used to record the source IPv6 address of o b4-ipv6-address, which is used to record the source IPv6 address
a packet received from a B4 element. This IPv6 address is of a packet received from a B4 element. This IPv6 address is
required to disambiguate between the overlapping IPv4 address required to disambiguate between the overlapping IPv4 address
space of subscribers. space of subscribers.
o The value of the Traffic Class field in the IPv6 header as o The value of the Traffic Class field in the IPv6 header as
received from a B4 element (v6-dscp): This information is used to received from a B4 element (v6-dscp): This information is used to
preserve DSCP marking when encapsulating/decapsulationg at the preserve DSCP marking when encapsulating/decapsulating at the
AFTR. AFTR.
o The IPv4 DSCP marking of the IPv4 packet received from a B4 o The IPv4 DSCP marking of the IPv4 packet received from a B4
element (internal-v4-dscp): This information can be used by the element (internal-v4-dscp): This information can be used by the
AFTR for setting the DSCP of packets relayed to a B4 element. AFTR for setting the DSCP of packets relayed to a B4 element.
o The IPv4 DSCP marking as set by the AFTR in its external interface o The IPv4 DSCP marking as set by the AFTR in its external interface
(external-v4-dscp): An AFTR can be instructed to preserve the same (external-v4-dscp): An AFTR can be instructed to preserve the same
marking or to set it to another value when forwarding an IPv4 marking or to set it to another value when forwarding an IPv4
packet destined to a remote IPv4 host. packet destined to a remote IPv4 host.
Access Control List (ACL) and Quality of Service (QoS) policies Access Control List (ACL) and Quality-of-Service (QoS) policies
discussed in Section 2.5 of [RFC6908] are out of scope. A YANG discussed in Section 2.5 of [RFC6908] are out of scope. A YANG
module for ACLs is documented in [I-D.ietf-netmod-acl-model]. module for ACLs is documented in [ACL-YANG].
Likewise, Port Control Protocol (PCP) related considerations Likewise, considerations that are related to the Port Control
discussed in Section 8.5 of [RFC6333] are out of scope. A YANG Protocol (PCP) and discussed in Section 8.5 of [RFC6333] are out of
module for PCP is documented in [I-D.boucadair-pcp-yang]. scope. A YANG module for PCP is documented in [YANG-PCP].
The YANG module "ietf-dslite" has the following structure: The YANG module "ietf-dslite" has the following structure:
module: ietf-dslite module: ietf-dslite
augment /if:interfaces/if:interface: augment /if:interfaces/if:interface:
+--rw ipv6-address? inet:ipv6-address +--rw ipv6-address? inet:ipv6-address
+--rw ipv4-address? inet:ipv4-address +--rw ipv4-address? inet:ipv4-address
+--rw aftr-ipv6-addr? inet:ipv6-address {b4}? +--rw aftr-ipv6-addr? inet:ipv6-address {b4}?
+--rw tunnel-mtu? uint16 +--rw tunnel-mtu? uint16
+--rw v6-v4-dscp-preservation? boolean +--rw v6-v4-dscp-preservation? boolean
skipping to change at page 6, line 43 skipping to change at page 6, line 43
augment /nat:nat/nat:instances/nat:instance augment /nat:nat/nat:instances/nat:instance
/nat:statistics/nat:mappings-statistics: /nat:statistics/nat:mappings-statistics:
+--ro active-softwires? yang:gauge32 {aftr}? +--ro active-softwires? yang:gauge32 {aftr}?
notifications: notifications:
+---n b4-address-change-limit-policy-violation {aftr}? +---n b4-address-change-limit-policy-violation {aftr}?
+--ro id -> /nat:nat/instances/instance/id +--ro id -> /nat:nat/instances/instance/id
+--ro policy-id -> /nat:nat/instances/instance/policy/id +--ro policy-id -> /nat:nat/instances/instance/policy/id
+--ro address inet:ipv6-address +--ro address inet:ipv6-address
Figure 2: DS-Lite YANG tree diagram Figure 2: DS-Lite YANG Tree Diagram
Examples to illustrate the use of the "ietf-dslite" module are Examples to illustrate the use of the "ietf-dslite" module are
provided in Appendix A and Appendix B. provided in Appendices A and B.
3. DS-Lite YANG Module 3. DS-Lite YANG Module
This module uses the tunnel interface identity defined in [RFC7224]. This module uses the tunnel interface identity defined in [RFC7224].
<CODE BEGINS> file "ietf-dslite@2018-02-26.yang" <CODE BEGINS> file "ietf-dslite@2019-01-10.yang"
module ietf-dslite {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite";
prefix dslite;
import ietf-inet-types {
prefix inet;
reference
"Section 4 of RFC 6991";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import iana-if-type {
prefix ianaift;
reference
"RFC 7224: IANA Interface Type YANG Module";
}
import ietf-nat {
prefix nat;
reference
"RFC YYYY: A YANG Module for Network Address Translation (NAT)
and Network Prefix Translation (NPT)";
}
import ietf-yang-types {
prefix yang;
reference
"Section 3 of RFC 6991";
}
organization "IETF Softwire Working Group"; module ietf-dslite {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite";
prefix dslite;
contact import ietf-inet-types {
prefix inet;
reference
"Section 4 of RFC 6991";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import iana-if-type {
prefix ianaift;
reference
"RFC 7224: IANA Interface Type YANG Module";
}
import ietf-nat {
prefix nat;
reference
"RFC 8512: A YANG Module for Network Address Translation (NAT)
and Network Prefix Translation (NPT)";
}
import ietf-yang-types {
prefix yang;
reference
"Section 3 of RFC 6991";
}
"WG Web: <https://datatracker.ietf.org/wg/softwire/> organization
WG List: <mailto:softwires@ietf.org> "IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwires@ietf.org>
Editor: Mohamed Boucadair Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com> <mailto:mohamed.boucadair@orange.com>
Author: Christian Jacquenet Author: Christian Jacquenet
<mailto:christian.jacquenet@orange.com> <mailto:christian.jacquenet@orange.com>
Author: Senthil Sivakumar Author: Senthil Sivakumar
<mailto:ssenthil@cisco.com>"; <mailto:ssenthil@cisco.com>";
description description
"This module is a YANG module for DS-Lite AFTR and B4 "This module is a YANG module for DS-Lite AFTR and B4
implementations. implementations.
Copyright (c) 2018 IETF Trust and the persons identified as Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved. authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents Relating to IETF Documents
(http://trustee.ietf.org/license-info). (http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see This version of this YANG module is part of RFC 8513; see
the RFC itself for full legal notices."; the RFC itself for full legal notices.";
revision 2018-02-26 { revision 2019-01-10 {
description description
"Initial revision."; "Initial revision.";
reference reference
"RFC XXXX: A YANG Data Model for Dual-Stack Lite (DS-Lite)"; "RFC 8513: A YANG Data Model for Dual-Stack Lite (DS-Lite)";
} }
/*
* Features
*/
feature b4 {
description
"The B4 element is a function implemented on a dual-stack-capable
node, either a directly connected device or a CPE, that creates
a tunnel to an AFTR.";
reference
"Section 5 of RFC 6333.";
}
feature aftr {
description
"An AFTR element is the combination of an IPv4-in-IPv6 tunnel
endpoint and an IPv4-IPv4 NAT implemented on the same node.";
reference
"Section 6 of RFC 6333.";
}
/*
* Augments
*/
augment "/if:interfaces/if:interface" {
when 'derived-from(if:type, "ianaift:tunnel")';
description
"Augments Interface module with DS-Lite parameters.
IANA interface types are maintained at this registry:
https://www.iana.org/assignments/ianaiftype-mib/ianaiftype-mib.
tunnel (131), -- Encapsulation interface";
leaf ipv6-address {
type inet:ipv6-address;
description
"IPv6 address of the local DS-Lite endpoint (AFTR or B4).";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf ipv4-address {
type inet:ipv4-address;
description
"IPv4 address of the local DS-Lite AFTR or B4.
192.0.0.1 is reserved for the AFTR element, while
192.0.0.0/29 is reserved for the B4 element.
This address can be used to report ICMP problems and will
appear in traceroute outputs.";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf aftr-ipv6-addr {
if-feature b4;
type inet:ipv6-address;
description
"Indicates the AFTR's IPv6 address to be used by a B4 element.";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
[RFC6908] specifies that since fragmentation and reassembly
is not optimal, the operator should do everything possible
to eliminate the need for it. If the operator uses simple
IPv4-in-IPv6 softwire, it is recommended that the MTU size
of the IPv6 network between the B4 and the AFTR accounts for
the additional overhead (40 bytes).";
reference
"RFC 6908: Deployment Considerations for Dual-Stack Lite";
}
leaf v6-v4-dscp-preservation {
type boolean;
description
"Copies the DSCP value from the IPv6 header and vice versa.
According to Section 2.10 of [RFC6908], operators should
use the uniform model by provisioning the network such
that the AFTR/B4 copies the DSCP value in the IPv4 header
to the Traffic Class field in the IPv6 header, after the
IPv4-in-IPv6 encapsulation.";
reference
"Section 2.10 of RFC 6908.";
}
}
augment "/nat:nat/nat:instances/nat:instance/nat:policy" {
when "derived-from-or-self(/nat:nat/nat:instances/nat:instance/" +
"nat:type, 'nat:napt44')" +
" and /nat:nat/nat:instances/nat:instance/" +
"nat:per-interface-binding='dslite'";
if-feature aftr;
description
"Augments the NAPT44 module with AFTR parameters.";
leaf max-softwires-per-subscriber {
type uint8;
default 1;
description
"Configures the maximum softwires per subscriber feature.
A subscriber is uniquely identified by means identity dslite {
of a subscriber mask (subscriber-mask-v6). base ianaift:tunnel;
description
"DS-Lite tunnel.";
}
This policy aims to prevent a misbehaving subscriber from /*
mounting several DS-Lite softwires that would consume * Features
additional AFTR resources (e.g., get more external ports */
if the quota were enforced on a per-softwire basis,
consume extra processing due to a large number of active
softwires).";
reference feature b4 {
"Section 4 of RFC 7785."; description
} "The B4 element is a function implemented on a dual-stack-capable
node, either a directly connected device or Customer Premises
Equipment (CPE), that creates a tunnel to an AFTR.";
reference
"Section 5 of RFC 6333";
}
feature aftr {
description
"An AFTR element is the combination of an IPv4-in-IPv6 tunnel
endpoint and an IPv4-IPv4 NAT implemented on the same node.";
reference
"Section 6 of RFC 6333";
}
leaf state-migrate { /*
type boolean; * Augments
default true; */
description
"State migration is enabled by default.
In the event a new IPv6 address is assigned to the B4 element, augment "/if:interfaces/if:interface" {
the AFTR should migrate existing state to be bound to the new when 'derived-from(if:type, "dslite")';
IPv6 address. This operation ensures that traffic destined to description
the previous B4's IPv6 address will be redirected to the newer "Augments Interface module with DS-Lite parameters.
B4's IPv6 address. The destination IPv6 address for tunneling
return traffic from the AFTR should be the last seen as the
B4's IPv6 source address from the user device (e.g., CPE).
The AFTR uses the subscriber-mask-v6 to determine whether two IANA interface types are maintained at this registry:
IPv6 addresses belong to the same CPE (e.g., if the <https://www.iana.org/assignments/ianaiftype-mib/>.
subscriber-mask-v6 is set to 56, the AFTR concludes that
2001:db8:100:100::1 and 2001:db8:100:100::2 belong to the same
CPE assigned with 2001:db8:100:100::/56).";
reference tunnel (131), -- Encapsulation interface";
"RFC 7785: Recommendations for Prefix Binding in the Context leaf ipv6-address {
of Softwire Dual-Stack Lite"; type inet:ipv6-address;
} description
"IPv6 address of the local DS-Lite endpoint (AFTR or B4).";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf ipv4-address {
type inet:ipv4-address;
description
"IPv4 address of the local DS-Lite AFTR or B4.
leaf b4-address-change-limit { 192.0.0.1 is reserved for the AFTR element, while
type uint32; 192.0.0.0/29 is reserved for the B4 element.
units "seconds";
default '1800';
description
"Minimum number of seconds between successive B4's IPv6 address
change from the same prefix.
Changing the source B4's IPv6 address may be used as an attack This address can be used to report ICMP problems and will
vector. Packets with a new B4's IPv6 address from the same appear in traceroute outputs.";
prefix should be rate-limited. reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf aftr-ipv6-addr {
if-feature "b4";
type inet:ipv6-address;
description
"Indicates the AFTR's IPv6 address to be used by a B4
element.";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
It is recommended to set this rate limit to 30 minutes; other RFC 6908 specifies that since fragmentation and reassembly
values can be set on a per-deployment basis."; are not optimal, the operator should do everything possible
to eliminate the need for them. If the operator uses simple
IPv4-in-IPv6 softwire, it is recommended that the MTU size
of the IPv6 network between the B4 and the AFTR account
for the additional overhead (40 bytes).";
reference
"RFC 6908: Deployment Considerations for Dual-Stack Lite";
}
leaf v6-v4-dscp-preservation {
type boolean;
description
"Copies the DSCP value from the IPv6 header, and vice versa.
reference According to Section 2.10 of RFC 6908, operators should
"RFC 7785: Recommendations for Prefix Binding in the Context use the uniform model by provisioning the network such
of Softwire Dual-Stack Lite"; that the AFTR/B4 copies the DSCP value in the IPv4 header
} to the Traffic Class field in the IPv6 header, after the
IPv4-in-IPv6 encapsulation.";
reference
"Section 2.10 of RFC 6908";
}
}
container mss-clamping { augment "/nat:nat/nat:instances/nat:instance/nat:policy" {
description when "derived-from-or-self(/nat:nat/nat:instances/nat:instance"
"MSS rewriting configuration to avoid IPv6 fragmentation."; + "/nat:type, 'nat:napt44')"
+ " and /nat:nat/nat:instances/nat:instance/"
+ "nat:per-interface-binding='dslite'";
if-feature "aftr";
description
"Augments the NAPT44 module with AFTR parameters.";
leaf max-softwires-per-subscriber {
type uint8;
default "1";
description
"Configures the maximum softwires per subscriber feature.
leaf enable { A subscriber is uniquely identified by means
type boolean; of a subscriber-mask (subscriber-mask-v6).
description
"Enable/disable MSS rewriting feature.";
}
leaf mss-value { This policy aims to prevent a misbehaving subscriber from
type uint16; mounting several DS-Lite softwires that would consume
units "octets"; additional AFTR resources (e.g., get more external ports
description if the quota was enforced on a per-softwire basis and
"Sets the MSS value to be used for MSS rewriting."; consume extra processing due to a large number of active
} softwires).";
} reference
} "Section 4 of RFC 7785";
}
leaf state-migrate {
type boolean;
default "true";
description
"State migration is enabled by default.
augment "/nat:nat/nat:instances/nat:instance/"+ In the event a new IPv6 address is assigned to the B4 element,
"nat:mapping-table/nat:mapping-entry" { the AFTR should migrate existing state to be bound to the new
when "derived-from-or-self(/nat:nat/nat:instances/nat:instance/" + IPv6 address. This operation ensures that traffic destined to
"nat:type, 'nat:napt44')" + the previous B4's IPv6 address will be redirected to the newer
" and /nat:nat/nat:instances/nat:instance/" + B4's IPv6 address. The destination IPv6 address for tunneling
"nat:per-interface-binding='dslite'"; return traffic from the AFTR should be the last seen as the
if-feature aftr; B4's IPv6 source address from the user device (e.g., CPE).
description
"Augments the NAPT44 mapping table with DS-Lite specifics.";
container b4-ipv6-address { The AFTR uses the subscriber-mask-v6 to determine whether two
description IPv6 addresses belong to the same CPE (e.g., if the
"Records the IPv6 address used by a B4 element and the last subscriber-mask-v6 is set to 56, the AFTR concludes that
time that address changed."; 2001:db8:100:100::1 and 2001:db8:100:100::2 belong to the same
CPE assigned with 2001:db8:100:100::/56).";
reference
"RFC 7785: Recommendations for Prefix Binding in the Context
of Softwire Dual-Stack Lite";
}
leaf b4-address-change-limit {
type uint32;
units "seconds";
default "1800";
description
"Minimum number of seconds between a successive B4's IPv6
address change from the same prefix.
leaf address { Changing the source B4's IPv6 address may be used as an attack
type inet:ipv6-address; vector. Packets with a new B4's IPv6 address from the same
description prefix should be rate-limited.
"Corresponds to the IPv6 address used by a B4 element.";
reference It is recommended that this rate limit be set to 30 minutes;
"RFC 6333: Dual-Stack Lite Broadband Deployments Following other values can be set on a per-deployment basis.";
IPv4 Exhaustion"; reference
} "RFC 7785: Recommendations for Prefix Binding in the Context
of Softwire Dual-Stack Lite";
}
container mss-clamping {
description
"MSS rewriting configuration to avoid IPv6 fragmentation.";
leaf enable {
type boolean;
description
"Enable/disable MSS rewriting feature.";
}
leaf mss-value {
type uint16;
units "octets";
description
"Sets the MSS value to be used for MSS rewriting.";
}
}
}
leaf last-address-change { augment "/nat:nat/nat:instances/nat:instance"
type yang:date-and-time; + "/nat:mapping-table/nat:mapping-entry" {
description when "derived-from-or-self(/nat:nat/nat:instances/nat:instance"
"Records the last time when the address changed."; + "/nat:type, 'nat:napt44')"
} + "and /nat:nat/nat:instances/nat:instance"
} + "/nat:per-interface-binding='dslite'";
if-feature "aftr";
description
"Augments the NAPT44 mapping table with DS-Lite specifics.";
container b4-ipv6-address {
description
"Records the IPv6 address used by a B4 element and the last
time that address changed.";
leaf address {
type inet:ipv6-address;
description
"Corresponds to the IPv6 address used by a B4 element.";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf last-address-change {
type yang:date-and-time;
description
"Records the last time that the address changed.";
}
leaf v6-dscp { }
when "/if:interfaces/if:interface/" + leaf v6-dscp {
"dslite:v6-v4-dscp-preservation='true'"; when "/if:interfaces/if:interface"
type inet:dscp; + "/dslite:v6-v4-dscp-preservation = 'true'";
description type inet:dscp;
"DSCP value used at the softwire level (i.e., IPv6 header)."; description
} "DSCP value used at the softwire level (i.e., IPv6 header).";
}
leaf internal-v4-dscp {
when "/if:interfaces/if:interface"
+ "/dslite:v6-v4-dscp-preservation = 'true'";
type inet:dscp;
description
"DSCP value of the encapsulated IPv4 packet.";
}
leaf external-v4-dscp {
when "/if:interfaces/if:interface"
+ "/dslite:v6-v4-dscp-preservation = 'true'";
type inet:dscp;
description
"DSCP value of the translated IPv4 packet as marked by
the AFTR.";
}
}
leaf internal-v4-dscp { augment "/nat:nat/nat:instances/nat:instance"
when "/if:interfaces/if:interface/" + + "/nat:statistics/nat:mappings-statistics" {
"dslite:v6-v4-dscp-preservation='true'"; if-feature "aftr";
type inet:dscp; description
description "Indicates the number of active softwires.";
"DSCP value of the encapsulated IPv4 packet."; leaf active-softwires {
} type yang:gauge32;
description
"The number of currently active softwires on the AFTR
instance.";
}
}
leaf external-v4-dscp { /*
when "/if:interfaces/if:interface/" + * Notifications
"dslite:v6-v4-dscp-preservation='true'"; */
type inet:dscp;
description
"DSCP value of the translated IPv4 packet as marked by
the AFTR.";
}
}
augment "/nat:nat/nat:instances/nat:instance/nat:statistics/" + notification b4-address-change-limit-policy-violation {
"nat:mappings-statistics" { if-feature "aftr";
if-feature aftr; description
description "Generates notifications when a B4 unsuccessfully attempts
"Indicates the number of active softwires."; to change the IPv6 address in a time shorter than the value
of b4-address-change-limit.
leaf active-softwires{ Notifications are rate-limited (notify-interval).";
type yang:gauge32; leaf id {
description type leafref {
"The number of currently active softwires on the AFTR path "/nat:nat/nat:instances/nat:instance/nat:id";
instance."; }
} mandatory true;
description
"NAT instance identifier.";
}
leaf policy-id {
type leafref {
path "/nat:nat/nat:instances/nat:instance/nat:policy/nat:id";
}
mandatory true;
description
"Policy identifier.";
}
leaf address {
type inet:ipv6-address;
mandatory true;
description
"B4's IPv6 address.";
}
}
} }
/* <CODE ENDS>
* Notifications
*/
notification b4-address-change-limit-policy-violation {
if-feature aftr;
description
"Generates notifications when a B4 unsuccessfully attempts
to change IPv6 address in a time shorter than the value of
b4-address-change-limit.
Notifications are rate-limited (notify-interval).";
leaf id {
type leafref {
path "/nat:nat/nat:instances/nat:instance/nat:id";
}
mandatory true;
description
"NAT instance identifier.";
}
leaf policy-id {
type leafref {
path "/nat:nat/nat:instances/nat:instance/nat:policy/nat:id";
}
mandatory true;
description
"Policy Identifier.";
}
leaf address {
type inet:ipv6-address;
mandatory true;
description
"B4's IPv6 address.";
}
}
}
<CODE ENDS>
4. Security Considerations 4. Security Considerations
The YANG module defined in this document is designed to be accessed The YANG module specified in this document defines a schema for data
via network management protocols such as NETCONF [RFC6241] or that is designed to be accessed via network management protocols such
RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
layer, and the mandatory-to-implement secure transport is Secure is the secure transport layer, and the mandatory-to-implement secure
Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
mandatory-to-implement secure transport is TLS [RFC5246]. is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The NETCONF access control model [RFC8341] provides the means to The Network Configuration Access Control Model (NACM) [RFC8341]
restrict access for particular NETCONF or RESTCONF users to a provides the means to restrict access for particular NETCONF or
preconfigured subset of all available NETCONF or RESTCONF protocol RESTCONF users to a preconfigured subset of all available NETCONF or
operations and content. RESTCONF protocol operations and content.
All data nodes defined in the YANG module which can be created, All data nodes defined in the YANG module that can be created,
modified and deleted (i.e., config true, which is the default) are modified, and deleted (i.e., config true, which is the default) are
considered sensitive. Write operations (e.g., edit-config) applied considered sensitive. Write operations (e.g., edit-config) applied
to these data nodes without proper protection can negatively affect to these data nodes without proper protection can negatively affect
network operations. An attacker who is able to access to the B4/AFTR network operations. An attacker who is able to access the B4/AFTR
can undertake various attacks, such as: can undertake various attacks, such as:
o Set the value of 'aftr-ipv6-addr' on the B4 to point to an o Setting the value of 'aftr-ipv6-addr' on the B4 to point to an
illegitimate AFTR so that it can intercept all the traffic sent by illegitimate AFTR so that it can intercept all the traffic sent by
a B4. Illegitimately intercepting users' traffic is a attack with a B4. Illegitimately intercepting users' traffic is an attack
severe implications on privacy. with severe implications on privacy.
o Set the MTU to a low value which may increase the number of o Setting the MTU to a low value, which may increase the number of
fragments ('tunnel-mtu' for both B4 and AFTR). fragments ('tunnel-mtu' for both B4 and AFTR).
o Set 'max-softwire-per-subscriber' to an arbitrary high value, o Setting 'max-softwire-per-subscriber' to an arbitrary high value,
which will be exploited by a misbehaving user to grab more which will be exploited by a misbehaving user to grab more
resources (by mounting as many softwires as required to get more resources (by mounting as many softwires as required to get more
external IP addresses/ports) or to perform a Denial-of-Service on external IP addresses/ports) or to perform a DoS on the AFTR by
the AFTR by mounting a massive number of softwires. mounting a massive number of softwires.
o Set 'state-migrate' to 'false' on the AFTR. This action may lead o Setting 'state-migrate' to 'false' on the AFTR. This action may
to a service degradation for the users. lead to a service degradation for the users.
o Set 'b4-address-change-limit" to an arbitrary low value can ease o Setting 'b4-address-change-limit' to an arbitrary low value can
DoS attacks based on frequent change of B4 IPv6 address. ease DoS attacks based on frequent change of the B4 IPv6 address.
o Set 'v6-v4-dscp-preservation' to 'false" may lead to a service o Setting 'v6-v4-dscp-preservation' to 'false" may lead to a service
degradation if some policies are applied on the network based on degradation if some policies are applied on the network based on
the DSCP value. the DSCP value.
Additional security considerations are discussed in Additional security considerations are discussed in [RFC8512].
[I-D.ietf-opsawg-nat-yang].
Security considerations related to DS-Lite are discussed in Security considerations related to DS-Lite are discussed in
[RFC6333]. [RFC6333].
5. IANA Considerations 5. IANA Considerations
This document requests IANA to register the following URI in the IANA has registered the following URI in the "ns" subregistry within
"IETF XML Registry" [RFC3688]: the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-dslite URI: urn:ietf:params:xml:ns:yang:ietf-dslite
Registrant Contact: The IESG. Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace. XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG module in IANA has registered the following YANG module in the "YANG Module
the "YANG Module Names" registry [RFC7950]. Names" subregistry [RFC7950] within the "YANG Parameters" registry.
name: ietf-dslite name: ietf-dslite
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite namespace: urn:ietf:params:xml:ns:yang:ietf-dslite
prefix: dslite prefix: dslite
reference: RFC XXXX reference: RFC 8513
6. Acknowledgements
Thanks to Qin Wu, Benoit Claise, and Andy Bierman who helped for
identifying compiling errors. Mahesh Jethanandani provided early
yangdoctors reviews; many thanks to him.
Many thanks to Ian Farrer and Tom Petch for the review and comments.
7. References
7.1. Normative references 6. References
[I-D.ietf-opsawg-nat-yang] 6.1. Normative References
Boucadair, M., Sivakumar, S., Jacquenet, C., Vinapamula,
S., and Q. Wu, "A YANG Module for Network Address
Translation (NAT) and Network Prefix Translation (NPT)",
draft-ietf-opsawg-nat-yang-14 (work in progress), March
2018.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004, DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>. <https://www.rfc-editor.org/info/rfc3688>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/info/rfc5246>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>. <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>. <https://www.rfc-editor.org/info/rfc6242>.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
skipping to change at page 17, line 44 skipping to change at page 17, line 26
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341, Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018, DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>. <https://www.rfc-editor.org/info/rfc8341>.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface [RFC8343] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
<https://www.rfc-editor.org/info/rfc8343>. <https://www.rfc-editor.org/info/rfc8343>.
7.2. Informative references [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[I-D.boucadair-pcp-yang] [RFC8512] Boucadair, M., Ed., Sivakumar, S., Jacquenet, C.,
Boucadair, M., Jacquenet, C., Sivakumar, S., and S. Vinapamula, S., and Q. Wu, "A YANG Module for Network
Vinapamula, "YANG Modules for the Port Control Protocol Address Translation (NAT) and Network Prefix Translation
(PCP)", draft-boucadair-pcp-yang-05 (work in progress), (NPT)", RFC 8512, DOI 10.17487/RFC8512, January 2019,
October 2017. <https://www.rfc-editor.org/info/rfc8512>.
[I-D.ietf-netmod-acl-model] 6.2. Informative References
Jethanandani, M., Huang, L., Agarwal, S., and D. Blair,
"Network Access Control List (ACL) YANG Data Model", [ACL-YANG] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair,
draft-ietf-netmod-acl-model-19 (work in progress), April "Network Access Control List (ACL) YANG Data Model", Work
in Progress, draft-ietf-netmod-acl-model-21, November
2018. 2018.
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network [RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022, Address Translator (Traditional NAT)", RFC 3022,
DOI 10.17487/RFC3022, January 2001, DOI 10.17487/RFC3022, January 2001,
<https://www.rfc-editor.org/info/rfc3022>. <https://www.rfc-editor.org/info/rfc3022>.
[RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG [RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and
Data Model Documents", RFC 6087, DOI 10.17487/RFC6087, M. Boucadair, "Deployment Considerations for Dual-Stack
January 2011, <https://www.rfc-editor.org/info/rfc6087>.
[RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M.
Boucadair, "Deployment Considerations for Dual-Stack
Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013, Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013,
<https://www.rfc-editor.org/info/rfc6908>. <https://www.rfc-editor.org/info/rfc6908>.
[RFC7785] Vinapamula, S. and M. Boucadair, "Recommendations for [RFC7785] Vinapamula, S. and M. Boucadair, "Recommendations for
Prefix Binding in the Context of Softwire Dual-Stack Prefix Binding in the Context of Softwire Dual-Stack
Lite", RFC 7785, DOI 10.17487/RFC7785, February 2016, Lite", RFC 7785, DOI 10.17487/RFC7785, February 2016,
<https://www.rfc-editor.org/info/rfc7785>. <https://www.rfc-editor.org/info/rfc7785>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>. <https://www.rfc-editor.org/info/rfc8340>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
[YANG-PCP] Boucadair, M., Jacquenet, C., Sivakumar, S., and
S. Vinapamula, "YANG Modules for the Port Control Protocol
(PCP)", Work in Progress, draft-boucadair-pcp-yang-05,
October 2017.
Appendix A. B4 Example Appendix A. B4 Example
The following example shows a B4 element (2001:db8:0:1::1) that is The following example shows a B4 element (2001:db8:0:1::1) that is
configured with an AFTR element (2001:db8:0:2::1). The B4 element is configured with an AFTR element (2001:db8:0:2::1). The B4 element is
also instructed to preserve the DSCP marking. also instructed to preserve the DSCP marking.
<interfaces> <interfaces>
<interface> <interface>
<name>myB4</name> <name>myB4</name>
<type>ianaift:tunnel</type> <type>dslite:dslite</type>
<enabled>true</enabled> <enabled>true</enabled>
<dslite:ipv6-address> <dslite:ipv6-address>
2001:db8:0:1::1 2001:db8:0:1::1
</dslite:ipv6-address> </dslite:ipv6-address>
<dslite:aftr-ipv6-addr> <dslite:aftr-ipv6-addr>
2001:db8:0:2::1 2001:db8:0:2::1
</dslite:aftr-ipv6-addr> </dslite:aftr-ipv6-addr>
<dslite:v6-v4-dscp-preservation> <dslite:v6-v4-dscp-preservation>
true true
</dslite:v6-v4-dscp-preservation> </dslite:v6-v4-dscp-preservation>
</interface> </interface>
</interfaces> </interfaces>
Appendix B. AFTR Examples Appendix B. AFTR Examples
The following example shows an AFTR that is reachable at The following example shows an AFTR that is reachable at
2001:db8:0:2::1. Also, this XML snippet indicates that the AFTR is 2001:db8:0:2::1. Also, this XML snippet indicates that the AFTR is
provided with an IPv4 address (192.0.0.1) to be used for provided with an IPv4 address (192.0.0.1) to be used for
troubleshooting purposes such as reporting problems to B4s. troubleshooting purposes such as reporting problems to B4s.
Note that a subscriber is identified by a subscriber mask ([RFC7785]) Note that a subscriber is identified by a subscriber-mask [RFC7785]
that can be configured by means of [I-D.ietf-opsawg-nat-yang]. that can be configured by means of [RFC8512].
<interfaces> <interfaces>
<interface> <interface>
<name>myAFTR</name> <name>myAFTR</name>
<type>ianaift:tunnel</type> <type>dslite:dslite</type>
<enabled>true</enabled> <enabled>true</enabled>
<dslite:ipv6-address>2001:db8:0:2::1</dslite:ipv6-address> <dslite:ipv6-address>2001:db8:0:2::1</dslite:ipv6-address>
<dslite:ipv4-address>192.0.0.1</dslite:ipv4-address> <dslite:ipv4-address>192.0.0.1</dslite:ipv4-address>
</interface> </interface>
</interfaces> </interfaces>
The following shows an XML excerpt depicting a dynamic UDP mapping The following shows an XML excerpt depicting a dynamic UDP mapping
entry maintained by a DS-Lite AFTR for a packet received from the B4 entry maintained by a DS-Lite AFTR for a packet received from the B4
element introduced in Appendix A. Concretely, this UDP packet element introduced in Appendix A. Concretely, this UDP packet
received with a source IPv6 address (2001:db8:0:1::1), a source IPv4 received with a source IPv6 address (2001:db8:0:1::1), a source IPv4
address (192.0.2.1), and source port number (1568) is translated into address (192.0.2.1), and a source port number (1568) is translated
a UDP packet having a source IPv4 address (198.51.100.1) and source into a UDP packet having a source IPv4 address (198.51.100.1) and
port number (15000). The remaining lifetime of this mapping is 300 source port number (15000). The remaining lifetime of this mapping
seconds. is 300 seconds.
<mapping-entry> <mapping-entry>
<index>15</index> <index>15</index>
<type> <type>
dynamic-explicit dynamic-explicit
</type> </type>
<transport-protocol> <transport-protocol>
17 17
</transport-protocol> </transport-protocol>
<dslite:b4-ipv6-address> <dslite:b4-ipv6-address>
skipping to change at page 20, line 42 skipping to change at page 21, line 5
<external-src-port> <external-src-port>
<start-port-number> <start-port-number>
15000 15000
</start-port-number> </start-port-number>
</external-src-port> </external-src-port>
<lifetime> <lifetime>
300 300
</lifetime> </lifetime>
</mapping-entry> </mapping-entry>
Acknowledgements
Thanks to Qin Wu, Benoit Claise, and Andy Bierman who helped to
identify compiling errors. Mahesh Jethanandani provided early YANG
Doctors reviews; many thanks to him.
Many thanks to Ian Farrer and Tom Petch for their reviews and
comments.
Authors' Addresses Authors' Addresses
Mohamed Boucadair Mohamed Boucadair
Orange Orange
Rennes 35000 Rennes 35000
France France
EMail: mohamed.boucadair@orange.com Email: mohamed.boucadair@orange.com
Christian Jacquenet Christian Jacquenet
Orange Orange
Rennes 35000 Rennes 35000
France France
EMail: christian.jacquenet@orange.com Email: christian.jacquenet@orange.com
Senthil Sivakumar Senthil Sivakumar
Cisco Systems Cisco Systems
7100-8 Kit Creek Road 7100-8 Kit Creek Road
Research Triangle Park, North Carolina 27709 Research Triangle Park, North Carolina 27709
USA United States of America
Phone: +1 919 392 5158 Phone: +1-919-392-5158
EMail: ssenthil@cisco.com Email: ssenthil@cisco.com
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