Internet Engineering Task Force (IETF) M. Boucadair
Request for Comments: 8513 C. Jacquenet
Category: Standards Track Orange
ISSN: 2070-1721 S. Sivakumar
Cisco Systems
January 2019
Internet Engineering Task Force (IETF) M. Boucadair
Request for Comments: 8513 C. Jacquenet
Category: Standards Track Orange
ISSN: 2070-1721 S. Sivakumar
Cisco Systems
January 2019
A YANG Data Model for Dual-Stack Lite (DS-Lite)
双栈Lite（DS-Lite）的YANG数据模型
Abstract
摘要
This document defines a YANG module for the Dual-Stack Lite (DS-Lite) Address Family Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements.
本文件为双栈Lite（DS Lite）地址系列转换路由器（AFTR）和基本桥接宽带（B4）元件定义了一个YANG模块。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 7841第2节。
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.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问https://www.rfc-editor.org/info/rfc8513.
Copyright Notice
版权公告
Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.
版权（c）2019 IETF信托基金和被确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(https://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. DS-Lite YANG Module: An Overview . . . . . . . . . . . . . . 4
3. DS-Lite YANG Module . . . . . . . . . . . . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . 15
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.1. Normative References . . . . . . . . . . . . . . . . . . 16
6.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. B4 Example . . . . . . . . . . . . . . . . . . . . . 19
Appendix B. AFTR Examples . . . . . . . . . . . . . . . . . . . 19
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. DS-Lite YANG Module: An Overview . . . . . . . . . . . . . . 4
3. DS-Lite YANG Module . . . . . . . . . . . . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . 15
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.1. Normative References . . . . . . . . . . . . . . . . . . 16
6.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. B4 Example . . . . . . . . . . . . . . . . . . . . . 19
Appendix B. AFTR Examples . . . . . . . . . . . . . . . . . . . 19
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
This document defines a data model for DS-Lite [RFC6333], using the YANG data modeling language [RFC7950]. Both the Address Family Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements are covered by this specification.
本文档使用YANG数据建模语言[RFC7950]为DS Lite[RFC6333]定义了一个数据模型。本规范涵盖地址族转换路由器（AFTR）和基本桥接宽带（B4）元件。
Figure 1 is a slight adaptation of Figure 1 from RFC 6333 and is provided here for the convenience of the reader.
图1是RFC 6333中图1的轻微修改，此处提供图1是为了方便读者。
+-----------+
| Host |
+-----+-----+
|192.0.2.1
|
|
|192.0.2.2
+---------|---------+
| | |
| Home router |
|+--------+--------+|
|| B4 ||
|+--------+--------+|
+--------|||--------+
|||2001:db8:0:1::1
|||
|||<-IPv4-in-IPv6 Softwire
|||
-------|||-------
/ ||| \
| ISP core network |
\ ||| /
-------|||-------
|||
|||2001:db8:0:2::1
+--------|||--------+
| AFTR |
|+--------+--------+|
|| Concentrator ||
|+--------+--------+|
| |NAT| |
| +-+-+ |
+---------|---------+
|198.51.100.1
|
--------|--------
/ | \
| Internet |
\ | /
--------|--------
|
|203.0.113.1
+-----+-----+
| IPv4 Host |
+-----------+
+-----------+
| Host |
+-----+-----+
|192.0.2.1
|
|
|192.0.2.2
+---------|---------+
| | |
| Home router |
|+--------+--------+|
|| B4 ||
|+--------+--------+|
+--------|||--------+
|||2001:db8:0:1::1
|||
|||<-IPv4-in-IPv6 Softwire
|||
-------|||-------
/ ||| \
| ISP core network |
\ ||| /
-------|||-------
|||
|||2001:db8:0:2::1
+--------|||--------+
| AFTR |
|+--------+--------+|
|| Concentrator ||
|+--------+--------+|
| |NAT| |
| +-+-+ |
+---------|---------+
|198.51.100.1
|
--------|--------
/ | \
| Internet |
\ | /
--------|--------
|
|203.0.113.1
+-----+-----+
| IPv4 Host |
+-----------+
Figure 1: DS-Lite Base Architecture
图1:DS Lite基本架构
DS-Lite deployment considerations are discussed in [RFC6908].
[RFC6908]中讨论了DS Lite部署注意事项。
This document follows the guidelines of [RFC8407], uses the common YANG types defined in [RFC6991], and adopts the Network Management Datastore Architecture (NMDA) [RFC8342].
本文件遵循[RFC8407]的指南，使用[RFC6991]中定义的常见类型，并采用网络管理数据存储体系结构（NMDA）[RFC8342]。
This document makes use of the terms defined in Section 3 of [RFC6333].
本文件使用了[RFC6333]第3节中定义的术语。
The terminology for describing YANG data models is defined in [RFC7950].
[RFC7950]中定义了描述数据模型的术语。
The meaning of the symbols in tree diagrams is defined in [RFC8340].
[RFC8340]中定义了树形图中符号的含义。
As shown in Figure 1:
如图1所示：
o The AFTR element is a combination of an IPv4-in-IPv6 tunnel and a NAPT function (Section 2.2 of [RFC3022]).
o AFTR元素是IPv4-in-IPv6隧道和NAPT功能的组合（RFC3022第2.2节）。
o The B4 element is an IPv4-in-IPv6 tunnel.
o B4元素是IPv4-in-IPv6隧道。
Therefore, the DS-Lite YANG module is designed to augment both the Interfaces YANG module [RFC8343] and the NAT YANG module [RFC8512] with DS-Lite-specific features.
因此，DS-Lite YANG模块的设计目的是用DS-Lite特有的功能来扩充接口YANG模块[RFC8343]和NAT-YANG模块[RFC8512]。
The YANG "feature" statement is used to distinguish which of the DS-Lite elements ('aftr' or 'b4') is relevant for a specific data node.
YANG“feature”语句用于区分哪些DS Lite元素（“aftr”或“b4”）与特定数据节点相关。
Concretely, the DS-Lite YANG module (Figure 2) augments the Interfaces YANG module with the following:
具体而言，DS Lite YANG模块（图2）通过以下内容扩展了YANG模块的接口：
o An IPv6 address used by the tunnel endpoint (AFTR or B4) for sending and receiving IPv4-in-IPv6 packets (ipv6-address).
o 隧道端点（AFTR或B4）用于发送和接收IPv6中的IPv4数据包（IPv6地址）的IPv6地址。
o An IPv4 address that is used by the tunnel endpoint (AFTR or B4) for troubleshooting purposes (ipv4-address).
o 隧道终结点（AFTR或B4）用于故障排除目的的IPv4地址（IPv4地址）。
o An IPv6 address used by a B4 element to reach its AFTR (aftr-ipv6-addr).
o B4元素用于到达其AFTR（AFTR-IPv6-addr）的IPv6地址。
o The tunnel MTU used to avoid fragmentation (tunnel-mtu).
o 用于避免碎片的隧道MTU（隧道MTU）。
o A policy to instruct the tunnel endpoint (AFTR or B4) whether it must preserve Differentiated Services Code Point (DSCP) marking when encapsulating/decapsulating packets (v6-v4-dscp-preservation).
o 用于指示隧道端点（AFTR或B4）在封装/解除封装数据包时是否必须保留区分服务代码点（DSCP）标记的策略（v6-v4-DSCP-preservation）。
In addition, the DS-Lite YANG module augments the NAT YANG module (policy, in particular) with the following:
此外，DS-Lite YANG模块通过以下内容扩展了NAT-YANG模块（尤其是策略）：
o A policy to limit the number of DS-Lite softwires per subscriber (max-softwire-per-subscriber).
o 限制每个订阅者的DS-Lite软线数量的策略（每个订阅者的最大软线数）。
o A policy to instruct the AFTR whether a state can be automatically migrated (state-migrate).
o 指示AFTR是否可以自动迁移状态（状态迁移）的策略。
o Further, in order to prevent a Denial of Service (DoS) by frequently changing the source IPv6 address, 'b4-address-change-limit' is used to rate-limit such changes.
o 此外，为了通过频繁更改源IPv6地址来防止拒绝服务（DoS），使用“b4地址更改限制”对此类更改进行评级限制。
o An instruction to rewrite the TCP Maximum Segment Size (MSS) option (mss-clamping) to avoid TCP fragmentation.
o 重写TCP最大段大小（MSS）选项（MSS夹紧）以避免TCP碎片的指令。
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 augments the NAPT44 mapping entry with the following:
鉴于AFTR元素的NAPT表被扩展以包括传入数据包的源IPv6地址，DS Lite YANG模块使用以下内容扩充NAPT44映射条目：
o b4-ipv6-address, which is used to record the source IPv6 address of a packet received from a B4 element. This IPv6 address is required to disambiguate between the overlapping IPv4 address space of subscribers.
o b4-ipv6-address，用于记录从b4元素接收的数据包的源ipv6地址。需要此IPv6地址来消除订阅者的重叠IPv4地址空间之间的歧义。
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 preserve DSCP marking when encapsulating/decapsulating at the AFTR.
o 从B4元素（v6 dscp）接收到的IPv6标头中的Traffic Class字段的值：此信息用于在AFTR封装/解封时保留dscp标记。
o The IPv4 DSCP marking of the IPv4 packet received from a B4 element (internal-v4-dscp): This information can be used by the AFTR for setting the DSCP of packets relayed to a B4 element.
o 从B4元素接收的IPv4数据包的IPv4 DSCP标记（内部-v4-DSCP）：AFTR可使用此信息设置中继到B4元素的数据包的DSCP。
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 marking or to set it to another value when forwarding an IPv4 packet destined to a remote IPv4 host.
o AFTR在其外部接口（external-v4-DSCP）中设置的IPv4 DSCP标记：在将IPv4数据包转发到远程IPv4主机时，可以指示AFTR保留相同的标记或将其设置为另一个值。
Access Control List (ACL) and Quality-of-Service (QoS) policies discussed in Section 2.5 of [RFC6908] are out of scope. A YANG module for ACLs is documented in [ACL-YANG].
[RFC6908]第2.5节中讨论的访问控制列表（ACL）和服务质量（QoS）策略超出范围。ACL的YANG模块记录在[ACL-YANG]中。
Likewise, considerations that are related to the Port Control Protocol (PCP) and discussed in Section 8.5 of [RFC6333] are out of scope. A YANG module for PCP is documented in [YANG-PCP].
类似地，[RFC6333]第8.5节中讨论的与端口控制协议（PCP）相关的注意事项也不在范围之内。PCP的YANG模块记录在[YANG-PCP]中。
The YANG module "ietf-dslite" has the following structure:
模块“ietf dslite”具有以下结构：
module: ietf-dslite
augment /if:interfaces/if:interface:
+--rw ipv6-address? inet:ipv6-address
+--rw ipv4-address? inet:ipv4-address
+--rw aftr-ipv6-addr? inet:ipv6-address {b4}?
+--rw tunnel-mtu? uint16
+--rw v6-v4-dscp-preservation? boolean
augment /nat:nat/nat:instances/nat:instance/nat:policy:
+--rw max-softwires-per-subscriber? uint8 {aftr}?
+--rw state-migrate? boolean {aftr}?
+--rw b4-address-change-limit? uint32 {aftr}?
+--rw mss-clamping {aftr}?
+--rw enable? boolean
+--rw mss-value? uint16
augment /nat:nat/nat:instances/nat:instance
/nat:mapping-table/nat:mapping-entry:
+--rw b4-ipv6-address {aftr}?
| +--rw address? inet:ipv6-address
| +--rw last-address-change? yang:date-and-time
+--rw v6-dscp? inet:dscp {aftr}?
+--rw internal-v4-dscp? inet:dscp {aftr}?
+--rw external-v4-dscp? inet:dscp {aftr}?
augment /nat:nat/nat:instances/nat:instance
/nat:statistics/nat:mappings-statistics:
+--ro active-softwires? yang:gauge32 {aftr}?
module: ietf-dslite
augment /if:interfaces/if:interface:
+--rw ipv6-address? inet:ipv6-address
+--rw ipv4-address? inet:ipv4-address
+--rw aftr-ipv6-addr? inet:ipv6-address {b4}?
+--rw tunnel-mtu? uint16
+--rw v6-v4-dscp-preservation? boolean
augment /nat:nat/nat:instances/nat:instance/nat:policy:
+--rw max-softwires-per-subscriber? uint8 {aftr}?
+--rw state-migrate? boolean {aftr}?
+--rw b4-address-change-limit? uint32 {aftr}?
+--rw mss-clamping {aftr}?
+--rw enable? boolean
+--rw mss-value? uint16
augment /nat:nat/nat:instances/nat:instance
/nat:mapping-table/nat:mapping-entry:
+--rw b4-ipv6-address {aftr}?
| +--rw address? inet:ipv6-address
| +--rw last-address-change? yang:date-and-time
+--rw v6-dscp? inet:dscp {aftr}?
+--rw internal-v4-dscp? inet:dscp {aftr}?
+--rw external-v4-dscp? inet:dscp {aftr}?
augment /nat:nat/nat:instances/nat:instance
/nat:statistics/nat:mappings-statistics:
+--ro active-softwires? yang:gauge32 {aftr}?
notifications:
+---n b4-address-change-limit-policy-violation {aftr}?
+--ro id -> /nat:nat/instances/instance/id
+--ro policy-id -> /nat:nat/instances/instance/policy/id
+--ro address inet:ipv6-address
notifications:
+---n b4-address-change-limit-policy-violation {aftr}?
+--ro id -> /nat:nat/instances/instance/id
+--ro policy-id -> /nat:nat/instances/instance/policy/id
+--ro address inet:ipv6-address
Figure 2: DS-Lite YANG Tree Diagram
图2:DS Lite YANG树图
Examples to illustrate the use of the "ietf-dslite" module are provided in Appendices A and B.
附录A和B中提供了说明“ietf dslite”模块使用的示例。
This module uses the tunnel interface identity defined in [RFC7224].
此模块使用[RFC7224]中定义的隧道接口标识。
<CODE BEGINS> file "ietf-dslite@2019-01-10.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;
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 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";
}
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";
}
organization
"IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwires@ietf.org>
organization
"IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwires@ietf.org>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Christian Jacquenet
<mailto:christian.jacquenet@orange.com>
Author: Christian Jacquenet
<mailto:christian.jacquenet@orange.com>
Author: Senthil Sivakumar
<mailto:ssenthil@cisco.com>";
Author: Senthil Sivakumar
<mailto:ssenthil@cisco.com>";
description "This module is a YANG module for DS-Lite AFTR and B4 implementations.
description“该模块是用于DS Lite AFTR和B4实现的模块。
Copyright (c) 2018 IETF Trust and the persons identified as authors of the code. All rights reserved.
版权所有（c）2018 IETF信托基金和被确定为代码作者的人员。版权所有。
Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info).
根据IETF信托有关IETF文件的法律规定第4.c节规定的简化BSD许可证中包含的许可条款，允许以源代码和二进制格式重新分发和使用，无论是否修改(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8513; see the RFC itself for full legal notices.";
此模块的此版本是RFC 8513的一部分；有关完整的法律通知，请参见RFC本身。“；
revision 2019-01-10 {
description
"Initial revision.";
reference
"RFC 8513: A YANG Data Model for Dual-Stack Lite (DS-Lite)";
}
revision 2019-01-10 {
description
"Initial revision.";
reference
"RFC 8513: A YANG Data Model for Dual-Stack Lite (DS-Lite)";
}
identity dslite {
base ianaift:tunnel;
description
"DS-Lite tunnel.";
}
identity dslite {
base ianaift:tunnel;
description
"DS-Lite tunnel.";
}
/*
* Features
*/
/*
* Features
*/
feature b4 {
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 b4 {
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";
}
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
*/
/*
* Augments
*/
augment "/if:interfaces/if:interface" {
when 'derived-from(if:type, "dslite")';
description
"Augments Interface module with DS-Lite parameters.
augment "/if:interfaces/if:interface" {
when 'derived-from(if:type, "dslite")';
description
"Augments Interface module with DS-Lite parameters.
IANA interface types are maintained at this registry: <https://www.iana.org/assignments/ianaiftype-mib/>.
IANA接口类型在此注册表中维护：<https://www.iana.org/assignments/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.
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.
192.0.0.1为AFTR元件保留，而192.0.0.0/29为B4元件保留。
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
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.
element.";
reference
"RFC 6333: Dual-Stack Lite Broadband Deployments Following
IPv4 Exhaustion";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
RFC 6908 specifies that since fragmentation and reassembly
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.
RFC 6908 specifies that since fragmentation and reassembly
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.
According to Section 2.10 of RFC 6908, 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";
}
}
According to Section 2.10 of RFC 6908, 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.
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 of a subscriber-mask (subscriber-mask-v6).
订户通过订户掩码（订户掩码-v6）进行唯一标识。
This policy aims to prevent a misbehaving subscriber from
mounting several DS-Lite softwires that would consume
additional AFTR resources (e.g., get more external ports
if the quota was enforced on a per-softwire basis and
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.
This policy aims to prevent a misbehaving subscriber from
mounting several DS-Lite softwires that would consume
additional AFTR resources (e.g., get more external ports
if the quota was enforced on a per-softwire basis and
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.
In the event a new IPv6 address is assigned to the B4 element, the AFTR should migrate existing state to be bound to the new IPv6 address. This operation ensures that traffic destined to the previous B4's IPv6 address will be redirected to the newer 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).
如果将新的IPv6地址分配给B4元素，AFTR应迁移现有状态以绑定到新的IPv6地址。此操作确保发送到先前B4的IPv6地址的流量将重定向到较新的B4的IPv6地址。来自AFTR的隧道返回流量的目标IPv6地址应最后视为来自用户设备（例如，CPE）的B4 IPv6源地址。
The AFTR uses the subscriber-mask-v6 to determine whether two
IPv6 addresses belong to the same CPE (e.g., if the
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
"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.
The AFTR uses the subscriber-mask-v6 to determine whether two
IPv6 addresses belong to the same CPE (e.g., if the
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
"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.
Changing the source B4's IPv6 address may be used as an attack vector. Packets with a new B4's IPv6 address from the same prefix should be rate-limited.
改变源B4的IPv6地址可以用作攻击向量。来自同一前缀的具有新B4 IPv6地址的数据包应具有速率限制。
It is recommended that this rate limit be set to 30 minutes;
建议将该速率限制设置为30分钟；
other values can be set on a per-deployment basis.";
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.";
}
}
}
other values can be set on a per-deployment basis.";
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.";
}
}
}
augment "/nat:nat/nat:instances/nat:instance"
+ "/nat:mapping-table/nat:mapping-entry" {
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 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.";
}
augment "/nat:nat/nat:instances/nat:instance"
+ "/nat:mapping-table/nat:mapping-entry" {
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 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"
+ "/dslite:v6-v4-dscp-preservation = 'true'";
type inet:dscp;
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 v6-dscp {
when "/if:interfaces/if:interface"
+ "/dslite:v6-v4-dscp-preservation = 'true'";
type inet:dscp;
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.";
}
}
augment "/nat:nat/nat:instances/nat:instance"
+ "/nat:statistics/nat:mappings-statistics" {
if-feature "aftr";
description
"Indicates the number of active softwires.";
leaf active-softwires {
type yang:gauge32;
description
"The number of currently active softwires on the AFTR
instance.";
}
}
augment "/nat:nat/nat:instances/nat:instance"
+ "/nat:statistics/nat:mappings-statistics" {
if-feature "aftr";
description
"Indicates the number of active softwires.";
leaf active-softwires {
type yang:gauge32;
description
"The number of currently active softwires on the AFTR
instance.";
}
}
/*
* Notifications
*/
/*
* Notifications
*/
notification b4-address-change-limit-policy-violation {
if-feature "aftr";
description
"Generates notifications when a B4 unsuccessfully attempts
to change the IPv6 address in a time shorter than the value
of b4-address-change-limit.
notification b4-address-change-limit-policy-violation {
if-feature "aftr";
description
"Generates notifications when a B4 unsuccessfully attempts
to change the 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.";
}
}
}
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>
<代码结束>
The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].
本文档中指定的模块为数据定义了一个模式，该模式旨在通过网络管理协议（如NETCONF[RFC6241]或restcconf[RFC8040]）进行访问。最低的NETCONF层是安全传输层，实现安全传输的强制要求是安全Shell（SSH）[RFC6242]。最低的RESTCONF层是HTTPS，实现安全传输的强制层是TLS[RFC8446]。
The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.
网络配置访问控制模型（NACM）[RFC8341]提供了将特定NETCONF或RESTCONF用户的访问限制为所有可用NETCONF或RESTCONF协议操作和内容的预配置子集的方法。
All data nodes defined in the YANG module that can be created, modified, and deleted (i.e., config true, which is the default) are considered sensitive. Write operations (e.g., edit-config) applied to these data nodes without proper protection can negatively affect network operations. An attacker who is able to access the B4/AFTR can undertake various attacks, such as:
在YANG模块中定义的所有可以创建、修改和删除的数据节点（即默认的config true）都被认为是敏感的。应用于这些数据节点的写入操作（如编辑配置）如果没有适当的保护，可能会对网络操作产生负面影响。能够访问B4/AFTR的攻击者可以进行各种攻击，例如：
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 a B4. Illegitimately intercepting users' traffic is an attack with severe implications on privacy.
o 将B4上的“aftr-ipv6-addr”值设置为指向非法aftr，以便它可以拦截B4发送的所有流量。非法拦截用户流量是一种严重影响隐私的攻击。
o Setting the MTU to a low value, which may increase the number of fragments ('tunnel-mtu' for both B4 and AFTR).
o 将MTU设置为较低的值，这可能会增加碎片的数量（“B4和AFTR的隧道MTU”）。
o Setting 'max-softwire-per-subscriber' to an arbitrary high value, which will be exploited by a misbehaving user to grab more resources (by mounting as many softwires as required to get more external IP addresses/ports) or to perform a DoS on the AFTR by mounting a massive number of softwires.
o 将“每个订户的最大软线数”设置为任意高值，行为不端的用户将利用该值获取更多资源（根据需要挂载尽可能多的软线以获取更多外部IP地址/端口），或通过挂载大量软线在AFTR上执行DoS。
o Setting 'state-migrate' to 'false' on the AFTR. This action may lead to a service degradation for the users.
o 在AFTR上将“状态迁移”设置为“false”。此操作可能会导致用户的服务降级。
o Setting 'b4-address-change-limit' to an arbitrary low value can ease DoS attacks based on frequent change of the B4 IPv6 address.
o 将“b4地址更改限制”设置为任意低值可以缓解基于b4 IPv6地址频繁更改的DoS攻击。
o Setting 'v6-v4-dscp-preservation' to 'false" may lead to a service degradation if some policies are applied on the network based on the DSCP value.
o 如果基于dscp值在网络上应用了某些策略，则将“v6-v4-dscp-preservation”设置为“false”可能会导致服务降级。
Additional security considerations are discussed in [RFC8512].
[RFC8512]中讨论了其他安全注意事项。
Security considerations related to DS-Lite are discussed in [RFC6333].
[RFC6333]中讨论了与DS Lite相关的安全注意事项。
IANA has registered the following URI in the "ns" subregistry within the "IETF XML Registry" [RFC3688]:
IANA已在“IETF XML注册表”[RFC3688]的“ns”子区域中注册了以下URI：
URI: urn:ietf:params:xml:ns:yang:ietf-dslite Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace.
URI:urn:ietf:params:xml:ns:yang:ietf-dslite注册人联系人：IESG。XML：不适用；请求的URI是一个XML命名空间。
IANA has registered the following YANG module in the "YANG Module Names" subregistry [RFC7950] within the "YANG Parameters" registry.
IANA已在“YANG参数”注册表中的“YANG模块名称”子区[RFC7950]中注册了以下YANG模块。
name: ietf-dslite
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite
prefix: dslite
reference: RFC 8513
name: ietf-dslite
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite
prefix: dslite
reference: RFC 8513
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, <https://www.rfc-editor.org/info/rfc3688>.
[RFC3688]Mealling，M.，“IETF XML注册表”，BCP 81，RFC 3688，DOI 10.17487/RFC3688，2004年1月<https://www.rfc-editor.org/info/rfc3688>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, <https://www.rfc-editor.org/info/rfc6241>.
[RFC6241]Enns，R.，Ed.，Bjorklund，M.，Ed.，Schoenwaeld，J.，Ed.，和A.Bierman，Ed.，“网络配置协议（NETCONF）”，RFC 6241，DOI 10.17487/RFC6241，2011年6月<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, <https://www.rfc-editor.org/info/rfc6242>.
[RFC6242]Wasserman，M.“在安全外壳上使用NETCONF协议（SSH）”，RFC 6242，DOI 10.17487/RFC6242，2011年6月<https://www.rfc-editor.org/info/rfc6242>.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, <https://www.rfc-editor.org/info/rfc6333>.
[RFC6333]Durand，A.，Droms，R.，Woodyatt，J.，和Y.Lee，“IPv4耗尽后的双栈Lite宽带部署”，RFC 6333，DOI 10.17487/RFC6333，2011年8月<https://www.rfc-editor.org/info/rfc6333>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, <https://www.rfc-editor.org/info/rfc6991>.
[RFC6991]Schoenwaeld，J.，Ed.，“常见杨数据类型”，RFC 6991，DOI 10.17487/RFC69911913年7月<https://www.rfc-editor.org/info/rfc6991>.
[RFC7224] Bjorklund, M., "IANA Interface Type YANG Module", RFC 7224, DOI 10.17487/RFC7224, May 2014, <https://www.rfc-editor.org/info/rfc7224>.
[RFC7224]Bjorklund，M.，“IANA接口类型YANG模块”，RFC 7224，DOI 10.17487/RFC72242014年5月<https://www.rfc-editor.org/info/rfc7224>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, <https://www.rfc-editor.org/info/rfc7950>.
[RFC7950]Bjorklund，M.，Ed.“YANG 1.1数据建模语言”，RFC 7950，DOI 10.17487/RFC7950，2016年8月<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, <https://www.rfc-editor.org/info/rfc8040>.
[RFC8040]Bierman，A.，Bjorklund，M.，和K.Watsen，“RESTCONF协议”，RFC 8040，DOI 10.17487/RFC8040，2017年1月<https://www.rfc-editor.org/info/rfc8040>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, <https://www.rfc-editor.org/info/rfc8341>.
[RFC8341]Bierman，A.和M.Bjorklund，“网络配置访问控制模型”，STD 91，RFC 8341，DOI 10.17487/RFC8341，2018年3月<https://www.rfc-editor.org/info/rfc8341>.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, <https://www.rfc-editor.org/info/rfc8343>.
[RFC8343]Bjorklund，M.，“用于接口管理的YANG数据模型”，RFC 8343，DOI 10.17487/RFC8343，2018年3月<https://www.rfc-editor.org/info/rfc8343>.
[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>.
[RFC8446]Rescorla，E.“传输层安全（TLS）协议版本1.3”，RFC 8446，DOI 10.17487/RFC8446，2018年8月<https://www.rfc-editor.org/info/rfc8446>.
[RFC8512] Boucadair, M., Ed., Sivakumar, S., Jacquenet, C., Vinapamula, S., and Q. Wu, "A YANG Module for Network Address Translation (NAT) and Network Prefix Translation (NPT)", RFC 8512, DOI 10.17487/RFC8512, January 2019, <https://www.rfc-editor.org/info/rfc8512>.
[RFC8512]Boucadair，M.，Ed.，Sivakumar，S.，Jacquenet，C.，Vinapamula，S.，和Q.Wu，“网络地址转换（NAT）和网络前缀转换（NPT）的YANG模块”，RFC 8512，DOI 10.17487/RFC8512，2019年1月<https://www.rfc-editor.org/info/rfc8512>.
[ACL-YANG] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair, "Network Access Control List (ACL) YANG Data Model", Work in Progress, draft-ietf-netmod-acl-model-21, November 2018.
[ACL-YANG]Jethanandani，M.，Agarwal，S.，Huang，L.，和D.Blair，“网络访问控制列表（ACL）YANG数据模型”，正在进行的工作，草稿-ietf-netmod-ACL-Model-212018年11月。
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network Address Translator (Traditional NAT)", RFC 3022, DOI 10.17487/RFC3022, January 2001, <https://www.rfc-editor.org/info/rfc3022>.
[RFC3022]Srisuresh，P.和K.Egevang，“传统IP网络地址转换器（传统NAT）”，RFC 3022，DOI 10.17487/RFC3022，2001年1月<https://www.rfc-editor.org/info/rfc3022>.
[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, <https://www.rfc-editor.org/info/rfc6908>.
[RFC6908]Lee，Y.，Maglione，R.，Williams，C.，Jacquenet，C.，和M.Boucadair，“双堆栈Lite的部署注意事项”，RFC 6908，DOI 10.17487/RFC6908，2013年3月<https://www.rfc-editor.org/info/rfc6908>.
[RFC7785] Vinapamula, S. and M. Boucadair, "Recommendations for Prefix Binding in the Context of Softwire Dual-Stack Lite", RFC 7785, DOI 10.17487/RFC7785, February 2016, <https://www.rfc-editor.org/info/rfc7785>.
[RFC7785]Vinapamula，S.和M.Boucadair，“软线双栈Lite环境下前缀绑定的建议”，RFC 7785，DOI 10.17487/RFC7785，2016年2月<https://www.rfc-editor.org/info/rfc7785>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, <https://www.rfc-editor.org/info/rfc8340>.
[RFC8340]Bjorklund，M.和L.Berger，编辑，“杨树图”，BCP 215，RFC 8340，DOI 10.17487/RFC8340，2018年3月<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>.
[RFC8342]Bjorklund，M.，Schoenwaeld，J.，Shafer，P.，Watsen，K.，和R.Wilton，“网络管理数据存储体系结构（NMDA）”，RFC 8342，DOI 10.17487/RFC8342，2018年3月<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>.
[RFC8407]Bierman，A.，“包含YANG数据模型的文件的作者和审查者指南”，BCP 216，RFC 8407，DOI 10.17487/RFC8407，2018年10月<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.
[YANG-PCP]Boucadair，M.，Jacquenet，C.，Sivakumar，S.，和S.Vinapamula，“港口控制协议（PCP）的YANG模块”，正在进行的工作，草稿-Boucadair-PCP-YANG-052017年10月。
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 also instructed to preserve the DSCP marking.
下面的示例显示了配置了AFTR元素（2001:db8:0:2:：1）的B4元素（2001:db8:0:1:：1）。还指示B4元件保留DSCP标记。
<interfaces>
<interface>
<name>myB4</name>
<type>dslite:dslite</type>
<enabled>true</enabled>
<dslite:ipv6-address>
2001:db8:0:1::1
</dslite:ipv6-address>
<dslite:aftr-ipv6-addr>
2001:db8:0:2::1
</dslite:aftr-ipv6-addr>
<dslite:v6-v4-dscp-preservation>
true
</dslite:v6-v4-dscp-preservation>
</interface>
</interfaces>
<interfaces>
<interface>
<name>myB4</name>
<type>dslite:dslite</type>
<enabled>true</enabled>
<dslite:ipv6-address>
2001:db8:0:1::1
</dslite:ipv6-address>
<dslite:aftr-ipv6-addr>
2001:db8:0:2::1
</dslite:aftr-ipv6-addr>
<dslite:v6-v4-dscp-preservation>
true
</dslite:v6-v4-dscp-preservation>
</interface>
</interfaces>
The following example shows an AFTR that is reachable at 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 troubleshooting purposes such as reporting problems to B4s.
下面的示例显示了在2001:db8:0:2:：1可以访问的AFTR。此外，此XML片段表示AFTR提供了IPv4地址（192.0.0.1），用于故障排除，例如向B4s报告问题。
Note that a subscriber is identified by a subscriber-mask [RFC7785] that can be configured by means of [RFC8512].
请注意，订户由订户掩码[RFC7785]标识，该掩码可通过[RFC8512]配置。
<interfaces>
<interface>
<name>myAFTR</name>
<type>dslite:dslite</type>
<enabled>true</enabled>
<dslite:ipv6-address>2001:db8:0:2::1</dslite:ipv6-address>
<dslite:ipv4-address>192.0.0.1</dslite:ipv4-address>
</interface>
</interfaces>
<interfaces>
<interface>
<name>myAFTR</name>
<type>dslite:dslite</type>
<enabled>true</enabled>
<dslite:ipv6-address>2001:db8:0:2::1</dslite:ipv6-address>
<dslite:ipv4-address>192.0.0.1</dslite:ipv4-address>
</interface>
</interfaces>
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 element introduced in Appendix A. Concretely, this UDP packet received with a source IPv6 address (2001:db8:0:1::1), a source IPv4 address (192.0.2.1), and a source port number (1568) is translated
下面显示了一个XML摘录，其中描述了DS Lite AFTR为从附录a中介绍的B4元素接收的数据包维护的动态UDP映射条目。具体地说，此UDP数据包使用源IPv6地址（2001:db8:0:1:：1）、源IPv4地址（192.0.2.1）和源端口号（1568）进行了转换
into a UDP packet having a source IPv4 address (198.51.100.1) and source port number (15000). The remaining lifetime of this mapping is 300 seconds.
进入具有源IPv4地址（198.51.100.1）和源端口号（15000）的UDP数据包。此映射的剩余生存期为300秒。
<mapping-entry>
<index>15</index>
<type>
dynamic-explicit
</type>
<transport-protocol>
17
</transport-protocol>
<dslite:b4-ipv6-address>
<dslite:address>
2001:db8:0:1::1
</dslite:address>
</dslite:b4-ipv6-address>
<internal-src-address>
192.0.2.1
</internal-src-address>
<internal-src-port>
<start-port-number>
1568
</start-port-number>
</internal-src-port>
<external-src-address>
198.51.100.1
</external-src-address>
<external-src-port>
<start-port-number>
15000
</start-port-number>
</external-src-port>
<lifetime>
300
</lifetime>
</mapping-entry>
<mapping-entry>
<index>15</index>
<type>
dynamic-explicit
</type>
<transport-protocol>
17
</transport-protocol>
<dslite:b4-ipv6-address>
<dslite:address>
2001:db8:0:1::1
</dslite:address>
</dslite:b4-ipv6-address>
<internal-src-address>
192.0.2.1
</internal-src-address>
<internal-src-port>
<start-port-number>
1568
</start-port-number>
</internal-src-port>
<external-src-address>
198.51.100.1
</external-src-address>
<external-src-port>
<start-port-number>
15000
</start-port-number>
</external-src-port>
<lifetime>
300
</lifetime>
</mapping-entry>
Acknowledgements
致谢
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.
感谢秦武、贝诺特·克莱斯和安迪·比尔曼，他们帮助识别了编译错误。马赫什·杰塔南达尼（Mahesh Jethanandani）提供了早期的医生评论；非常感谢他。
Many thanks to Ian Farrer and Tom Petch for their reviews and comments.
非常感谢伊恩·法勒和汤姆·佩奇的评论和评论。
Authors' Addresses
作者地址
Mohamed Boucadair Orange Rennes 35000 France
穆罕默德·布卡代尔·奥兰治·雷恩35000法国
Email: mohamed.boucadair@orange.com
Email: mohamed.boucadair@orange.com
Christian Jacquenet Orange Rennes 35000 France
克里斯蒂安·雅克内特·奥兰治·雷恩35000法国
Email: christian.jacquenet@orange.com
Email: christian.jacquenet@orange.com
Senthil Sivakumar Cisco Systems 7100-8 Kit Creek Road Research Triangle Park, North Carolina 27709 United States of America
Senthil Sivakumar Cisco Systems 7100-8美国北卡罗来纳州Kit Creek Road研究三角公园27709
Phone: +1-919-392-5158
Email: ssenthil@cisco.com
Phone: +1-919-392-5158
Email: ssenthil@cisco.com