RFC 8676
YANG Modules for IPv4-in-IPv6 Address plus Port (A+P) Softwires
RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port (A+P) Softwires ✨
Title block tea 🫖
Okay bestie, the paperwork first! This is RFC 8676, titled YANG Modules for IPv4-in-IPv6 Address plus Port (A+P) Softwires. It was published in November 2019 as a Standards Track document, with ISSN 2070-1721. The editors are I. Farrer (Ed.) from Deutsche Telekom AG and M. Boucadair (Ed.) from Orange. The title block doesn't list anything it obsoletes or updates, so it's a clean start 💅
Abstract 🌸
This document defines YANG modules for configuring and running IPv4-in-IPv6 softwire Border Relays and Customer Premises Equipment. It covers three softwire mechanisms: Lightweight 4over6, Mapping of Address and Port with Encapsulation (MAP-E), and Mapping of Address and Port using Translation (MAP-T). Iconic 🦋
Status of This Memo 📜
This is an Internet Standards Track document. It's a product of the Internet Engineering Task Force (IETF), so it represents the consensus of the IETF community. It got public review and was approved for publication by the Internet Engineering Steering Group (IESG). For more info on Internet Standards, check out Section 2 of RFC 7841.
Want the latest status, any errata, or a way to send feedback? Head to https://www.rfc-editor.org/info/rfc8676 🧚
Copyright Notice ©️
Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) as they stand on the publication date. Read these carefully, because they spell out your rights and restrictions for this document. Code Components pulled out of this document must include the Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come with no warranty, as described in the Simplified BSD License. Be careful with that one, it's the fine print 🙈
Table of Contents 🗂️
1. Introduction
2. Terminology
3. Overview of the Modules
3.1. Overall Structure
3.2. Configuration for Additional Components
4. Softwire CE YANG Tree Diagram
4.1. CE Tree Diagram
4.2. Softwire CE Tree Diagram Description
5. Softwire BR YANG Tree Diagram
5.1. BR Tree Diagram
5.2. Softwire BR Tree Diagram Description
6. Softwire CE YANG Module
7. BR Softwire YANG Module
8. Common Softwire Element Groups YANG Module
9. Security Considerations
10. IANA Considerations
11. References
11.1. Normative References
11.2. Informative References
Appendix A. Configuration Examples
A.1. Configuration Example for a lw4o6 BR Binding-Table
A.2. Configuration Example for a MAP-E BR
A.3. lw4o6 CE Configuration Example
Acknowledgements
Contributors
Authors' Addresses1. Introduction 💖
The IETF Softwire Working Group has built several IPv4-in-IPv6 softwire mechanisms for different deployment contexts and constraints. This document is the companion to the architecture specs, and it's all about provisioning the Address plus Port (A+P) softwire functional elements: Border Routers (BRs) and Customer Edge (CE) devices. The CE is called "Customer Premises Equipment (CPE)" in [RFC7596]. The mechanisms covered here are Lightweight 4over6 (lw4o6) [RFC7596], Mapping of Address and Port with Encapsulation (MAP-E) [RFC7597], and Mapping of Address and Port using Translation (MAP-T) [RFC7599].
This document focuses on A+P mechanisms [RFC6346]. If you want a YANG module for Dual-Stack Lite (DS-Lite) [RFC6333], look at [RFC8513] instead ✨
This document defines YANG modules [RFC7950] that you can use to configure and manage A+P softwire elements over NETCONF [RFC6241] or RESTCONF [RFC8040]. They cover:
- Configuration
- Operational State
- Notifications
2. Terminology 📚
You'll want to be familiar with the concepts and terms in [RFC7596], [RFC7597], [RFC7599], and the YANG data modeling language in [RFC7950].
The YANG modules here follow the Network Management Datastore Architecture (NMDA) [RFC8342]. The meanings of the symbols in the tree diagrams are defined in [RFC8340] 🦋
The document uses the abbreviation 'BR' as a general term for softwire tunnel concentrators. That includes both MAP Border Routers [RFC7597] and Lightweight 4over6 lwAFTRs [RFC7596].
For brevity, "algorithm" refers to the "mapping algorithm" defined in [RFC7597].
A network element can support one or more instances of a softwire mechanism. Each instance (binding instances, MAP-E instances, or MAP-T instances) can have its own configuration and parameters. The term 'algo-instance' covers both MAP-E and MAP-T instances 🍓
3. Overview of the Modules 🎀
3.1. Overall Structure
The document defines two YANG modules for configuring and monitoring softwire functional elements:
ietf-softwire-ce
Provides configuration and monitoring for softwire CE element.
This module is defined as augments to the interface YANG module
[RFC8343].
ietf-softwire-br
Provides configuration and monitoring for softwire BR element.There's also one more module:
ietf-softwire-common
Contains groups of common functions that are imported into the
CE and BR modules.This setup means the modules can be extended to support more softwire mechanisms later, if that's ever needed 🌈
Inside the BR and CE modules, the YANG "feature" statement tells you which softwire mechanism is relevant for a given element's configuration. Each module includes a choice statement called 'ce-type', which can be either 'binding' or 'algorithm'. 'Binding' is for configuring Lightweight 4over6, and 'algorithm' is for configuring MAP-T or MAP-E.
Inside the 'algo-instances' container, there's a choice statement called 'data-plane', which picks MAP-E (encapsulation) or MAP-T (translation). Table 1 shows how these choices signal the softwire mechanism you want 👑
+--------------------+-----------+---------------+
| S46 Mechanism | ce-type? | data-plane? |
+====================+===========+===============+
| Lightweight 4over6 | binding | n/a |
+--------------------+-----------+---------------+
| MAP-E | algorithm | encapsulation |
+--------------------+-----------+---------------+
| MAP-T | algorithm | translation |
+--------------------+-----------+---------------+
Table 1: Softwire Mechanism Choice
Statement EnumerationNETCONF notifications are included too ⭐
🫣 Quick history tea: earlier drafts combined the softwire mechanisms by their associated technologies instead of by their function in the architecture. As the document got revised, it became clear that splitting the modules by their role in the architecture (CE or BR) was the better move. It follows the intended function and existing implementation approaches more closely.
3.2. Configuration for Additional Components
These softwire modules only cover configuration relevant to softwires. To fully provision a CE element, you might also need:
- IPv6 forwarding and routing configuration, so the CE can get one or more IPv6 prefixes for softwire use. A YANG module for routing management is described in [RFC8349].
- IPv4 routing configuration, to add one or more IPv4 destination prefix(es) reachable through the configured softwire. A YANG module for routing management is described in [RFC8349].
- Stateful NAT44/NAPT management, to optionally specify a port set (Port Set Identifier (PSID)) along with its length. A YANG module for NAT management is described in [RFC8512].
- Stateless NAT46 management, which is required by softwire-translation-based mechanisms (that is, the assignment of a Network-Specific Prefix for IPv4/IPv6 translation). A YANG module for NAT management is described in [RFC8512].
These functions already have YANG modules defined in other documents, so their functionality isn't duplicated here. Go check those out as needed. Appendix A.3 has XML examples showing how these modules work together 🧚
The CE needs minimal IPv6 configuration already in place so the NETCONF client can reach it and grab the softwire configuration. If it needs extra IPv6-specific configuration, the YANG modules defined in [RFC8344] and [RFC8349] can be used 💜
4. Softwire CE YANG Tree Diagram 🦋
4.1. CE Tree Diagram
okay so the CE module is the one that handles config and monitoring for every softwire mechanism in this doc: Lightweight 4over6, MAP-E, and MAP-T 🎀✨
It augments "ietf-interfaces", defined in [RFC8343], with an entry for the softwire. 💖 That entry is what you point at when you want to configure IPv4 forwarding features on the element. Oh, and it only gets added if tunnel type (Section 10) is set to 'aplusp' 🦋
Here's the tree structure of the softwire CE YANG module, bestie 💅
module: ietf-softwire-ce
augment /if:interfaces/if:interface:
+--rw softwire-payload-mtu? uint16
+--rw softwire-path-mru? uint16
+--rw (ce-type)?
+--:(binding) {binding-mode}?
| +--rw binding-ipv6info? union
| +--rw br-ipv6-addr inet:ipv6-address
+--:(algo) {map-e or map-t}?
+--rw algo-instances
+--rw algo-instance* [name]
+--rw name string
+--rw enable? boolean
+--rw algo-versioning
| +--rw version? uint64
| +--rw date? yang:date-and-time
+--rw (data-plane)?
| +--:(encapsulation) {map-e}?
| | +--rw br-ipv6-addr inet:ipv6-address
| +--:(translation) {map-t}?
| +--rw dmr-ipv6-prefix? inet:ipv6-prefix
+--rw ea-len uint8
+--rw rule-ipv6-prefix inet:ipv6-prefix
+--rw rule-ipv4-prefix inet:ipv4-prefix
+--rw forwarding boolean
augment /if:interfaces/if:interface/if:statistics:
+--ro sent-ipv4-packets?
| yang:zero-based-counter64
+--ro sent-ipv4-bytes?
| yang:zero-based-counter64
+--ro sent-ipv6-packets?
| yang:zero-based-counter64
+--ro sent-ipv6-bytes?
| yang:zero-based-counter64
+--ro rcvd-ipv4-packets?
| yang:zero-based-counter64
+--ro rcvd-ipv4-bytes?
| yang:zero-based-counter64
+--ro rcvd-ipv6-packets?
| yang:zero-based-counter64
+--ro rcvd-ipv6-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv4-packets?
| yang:zero-based-counter64
+--ro dropped-ipv4-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv6-packets?
| yang:zero-based-counter64
+--ro dropped-ipv6-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv4-fragments?
| yang:zero-based-counter64
+--ro dropped-ipv4-fragment-bytes?
| yang:zero-based-counter64
+--ro ipv6-fragments-reassembled?
| yang:zero-based-counter64
+--ro ipv6-fragments-bytes-reassembled?
| yang:zero-based-counter64
+--ro out-icmpv4-error-packets?
| yang:zero-based-counter64
+--ro out-icmpv4-error-bytes?
| yang:zero-based-counter64
+--ro out-icmpv6-error-packets?
| yang:zero-based-counter64
+--ro out-icmpv6-error-bytes?
yang:zero-based-counter64
notifications:
+---n softwire-ce-event {binding-mode}?
+--ro ce-binding-ipv6-addr-change inet:ipv6-address
Figure 1: Softwire CE YANG Tree Diagram4.2. Softwire CE Tree Diagram Description
Okay, here's the extra info on how a CE element actually runs 🧚 Let's go through it:
softwire-payload-mtu: this one is optional 🌸 You use it to set the IPv4 Maximum Transmission Unit (MTU) for the softwire. You'd only need it if the softwire implementation can't work out the right IPv4 MTU size on its own.softwire-path-mru: also optional ✨ This sets the maximum IPv6 softwire packet size that can be received, encapsulation/translation overhead included. You'd only need it if the implementation can't calculate the correct IPv4 payload Maximum Receive Unit (MRU) size automatically (see Section 3.2 of [RFC4213]).ce-type: this is a choice statement that lets you pick the binding mechanism or the algorithmic one 💜
Now for the binding side of things 🦋
binding-ipv6info: this tells you the IPv6 binding prefix type, which decides which IPv6 address gets used as the tunnel source. It can be 'ipv6-prefix' or 'ipv6-address'.br-ipv6-addr: this is the IPv6 address of the remote BR.
And here's the important algorithmic stuff 👑
algo-versioning: totally optional, but it lets you attach a version number and/or timestamp to the algorithm 📝 That can be handy for logging and data retention purposes [RFC7422]. The version number is picked to uniquely identify the algorithm configuration, and a new value gets written whenever the algorithm changes or a new algo-instance is created.forwarding: this says whether the rule can be used as a Forwarding Mapping Rule (FMR). If it isn't set, the rule is only a Basic Mapping Rule (BMR) and must not be used for forwarding. Check out Section 4.1 of [RFC7598] for more on that 🌈ea-len: sets the length of the Embedded-Address (EA), which is defined in the mapping rule for a MAP domain.data-plane: a choice statement for either encapsulation (MAP-E) or translation (MAP-T) 🍓br-ipv6-addr: defines the IPv6 address of the BR. This info is valid for MAP-E.dmr-ipv6-prefix: defines the Default Mapping Rule (DMR) IPv6 prefix of the BR. This info is valid for MAP-T.
And last but not least, the notification node 🔔
ce-binding-ipv6-addr-change: if the CE's binding IPv6 address changes for any reason, the NETCONF client gets notified. No surprises, periodt 💀✨
5. Softwire BR YANG Tree Diagram 🎀
5.1. BR Tree Diagram ✨
okay so the BR YANG module is the one doing the heavy lifting 💅 It gives you configuration and monitoring for ALL the softwire mechanisms in this document: Lightweight 4over6, MAP-E, and MAP-T. Three for the price of one, bestie 🦋
Here's the tree structure of this module (Figure 2 🌸):
module: ietf-softwire-br
+--rw br-instances
+--rw (br-type)?
+--:(binding) {binding-mode}?
| +--rw binding
| +--rw bind-instance* [name]
| +--rw name string
| +--rw binding-table-versioning
| | +--rw version? uint64
| | +--rw date? yang:date-and-time
| +--rw softwire-num-max uint32
| +--rw softwire-payload-mtu uint16
| +--rw softwire-path-mru uint16
| +--rw enable-hairpinning? boolean
| +--rw binding-table
| | +--rw binding-entry* [binding-ipv6info]
| | +--rw binding-ipv6info union
| | +--rw binding-ipv4-addr?
| | | inet:ipv4-address
| | +--rw port-set
| | | +--rw psid-offset? uint8
| | | +--rw psid-len uint8
| | | +--rw psid uint16
| | +--rw br-ipv6-addr?
| | inet:ipv6-address
| +--rw icmp-policy
| | +--rw icmpv4-errors
| | | +--rw allow-incoming-icmpv4? boolean
| | | +--rw icmpv4-rate? uint32
| | | +--rw generate-icmpv4-errors? boolean
| | +--rw icmpv6-errors
| | +--rw generate-icmpv6-errors? boolean
| | +--rw icmpv6-rate? uint32
| +--ro traffic-stat
| +--ro discontinuity-time yang:date-and-time
| +--ro sent-ipv4-packets?
| | yang:zero-based-counter64
| +--ro sent-ipv4-bytes?
| | yang:zero-based-counter64
| +--ro sent-ipv6-packets?
| | yang:zero-based-counter64
| +--ro sent-ipv6-bytes?
| | yang:zero-based-counter64
| +--ro rcvd-ipv4-packets?
| | yang:zero-based-counter64
| +--ro rcvd-ipv4-bytes?
| | yang:zero-based-counter64
| +--ro rcvd-ipv6-packets?
| | yang:zero-based-counter64
| +--ro rcvd-ipv6-bytes?
| | yang:zero-based-counter64
| +--ro dropped-ipv4-packets?
| | yang:zero-based-counter64
| +--ro dropped-ipv4-bytes?
| | yang:zero-based-counter64
| +--ro dropped-ipv6-packets?
| | yang:zero-based-counter64
| +--ro dropped-ipv6-bytes?
| | yang:zero-based-counter64
| +--ro dropped-ipv4-fragments?
| | yang:zero-based-counter64
| +--ro dropped-ipv4-fragment-bytes?
| | yang:zero-based-counter64
| +--ro ipv6-fragments-reassembled?
| | yang:zero-based-counter64
| +--ro ipv6-fragments-bytes-reassembled?
| | yang:zero-based-counter64
| +--ro out-icmpv4-error-packets?
| | yang:zero-based-counter64
| +--ro out-icmpv4-error-bytes?
| | yang:zero-based-counter64
| +--ro out-icmpv6-error-packets?
| | yang:zero-based-counter64
| +--ro out-icmpv6-error-bytes?
| | yang:zero-based-counter64
| +--ro dropped-icmpv4-packets?
| | yang:zero-based-counter64
| +--ro dropped-icmpv4-bytes?
| | yang:zero-based-counter64
| +--ro hairpin-ipv4-packets?
| | yang:zero-based-counter64
| +--ro hairpin-ipv4-bytes?
| | yang:zero-based-counter64
| +--ro active-softwire-num?
| uint32
+--:(algo) {map-e or map-t}?
+--rw algorithm
+--rw algo-instance* [name]
+--rw name string
+--rw enable? boolean
+--rw algo-versioning
| +--rw version? uint64
| +--rw date? yang:date-and-time
+--rw (data-plane)?
| +--:(encapsulation) {map-e}?
| | +--rw br-ipv6-addr inet:ipv6-address
| +--:(translation) {map-t}?
| +--rw dmr-ipv6-prefix? inet:ipv6-prefix
+--rw ea-len uint8
+--rw rule-ipv6-prefix inet:ipv6-prefix
+--rw rule-ipv4-prefix inet:ipv4-prefix
+--rw forwarding boolean
+--rw port-set
| +--rw psid-offset? uint8
| +--rw psid-len uint8
| +--rw psid uint16
+--ro traffic-stat
+--ro discontinuity-time yang:date-and-time
+--ro sent-ipv4-packets?
| yang:zero-based-counter64
+--ro sent-ipv4-bytes?
| yang:zero-based-counter64
+--ro sent-ipv6-packets?
| yang:zero-based-counter64
+--ro sent-ipv6-bytes?
| yang:zero-based-counter64
+--ro rcvd-ipv4-packets?
| yang:zero-based-counter64
+--ro rcvd-ipv4-bytes?
| yang:zero-based-counter64
+--ro rcvd-ipv6-packets?
| yang:zero-based-counter64
+--ro rcvd-ipv6-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv4-packets?
| yang:zero-based-counter64
+--ro dropped-ipv4-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv6-packets?
| yang:zero-based-counter64
+--ro dropped-ipv6-bytes?
| yang:zero-based-counter64
+--ro dropped-ipv4-fragments?
| yang:zero-based-counter64
+--ro dropped-ipv4-fragment-bytes?
| yang:zero-based-counter64
+--ro ipv6-fragments-reassembled?
| yang:zero-based-counter64
+--ro ipv6-fragments-bytes-reassembled?
| yang:zero-based-counter64
+--ro out-icmpv4-error-packets?
| yang:zero-based-counter64
+--ro out-icmpv4-error-bytes?
| yang:zero-based-counter64
+--ro out-icmpv6-error-packets?
| yang:zero-based-counter64
+--ro out-icmpv6-error-bytes?
yang:zero-based-counter64
notifications:
+---n softwire-binding-instance-event {binding-mode}?
| +--ro bind-name?
| | -> /br-instances/binding/bind-instance/name
| +--ro invalid-entry* leafref
| +--ro added-entry* inet:ipv6-address
| +--ro modified-entry* leafref
+---n softwire-algorithm-instance-event {map-e, map-t}?
+--ro algo-name
| -> /br-instances/algorithm/algo-instance/name
+--ro invalid-entry-id*
| -> /br-instances/algorithm/algo-instance/name
+--ro added-entry*
| -> /br-instances/algorithm/algo-instance/name
+--ro modified-entry*
-> /br-instances/algorithm/algo-instance/nameFigure 2: Softwire BR YANG Tree
5.2. Softwire BR Tree Diagram Description 🎀
so the leaves that are shared with the CE module? their descriptions are already in Section 4.2, so you don't need them twice 🙈 Here are the extra bits that are specific to the BR:
binding-table-versioning: optionally used to associate a version number and/or timestamp to the binding table. This can be used for logging or data retention purposes [RFC7422]. The version number is selected to uniquely identify the binding table configuration, and a new timestamp value is written whenever a change is made to the contents of the binding table or a new binding table list is created. 💜binding-entry: used to define the binding relationship between the 3-tuples{lwB4's IPv6 address/prefix, the allocated IPv4 address, restricted port-set}. For detailed information, please refer to [RFC7596]. 🧚softwire-num-max: used to set the maximum number of softwire binding rules that can be created on the lw4o6 element simultaneously. This parameter must not be set to zero, because that is equivalent to disabling the BR instance. 🍓active-softwire-num: holds the number of softwires currently provisioned on the BR element. 🌈
And a little extra on some of the important notification nodes 🔔:
invalid-entry,added-entry,modified-entry: used to notify the NETCONF client that a specific binding entry or MAP rule has expired, been invalidated, added, or modified. ⭐
6. Softwire CE YANG Module ✨
okay bestie, this is the CE side 🎀 The module pulls in [RFC6991], [RFC8343], and [RFC7224], and it also grabs the 'ietf-softwire-common' and 'iana-tunnel-type' modules from [RFC8675]. Then it's all about configuring and managing A+P Softwire CEs for Lightweight 4over6, MAP-E, and MAP-T 💅
<CODE BEGINS> file "ietf-softwire-ce@2019-11-16.yang"
module ietf-softwire-ce {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-ce";
prefix softwire-ce;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types, Section 4";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-softwire-common {
prefix softwire-common;
reference
"RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
import iana-tunnel-type {
prefix iana-tunnel-type;
reference
"RFC 8675: A YANG Data Model for Tunnel Interface Types";
}
organization
"IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwire@ietf.org>
Author: Qi Sun
<mailto:sunqi.ietf@gmail.com>
Author: Linhui Sun
<mailto:lh.sunlinh@gmail.com>
Author: Yong Cui
<mailto:yong@csnet1.cs.tsinghua.edu.cn>
Editor: Ian Farrer
<mailto:ian.farrer@telekom.de>
Author: Sladjana Zoric
<mailto:sladjana.zoric@telekom.de>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Rajiv Asati
<mailto:rajiva@cisco.com>";
description
"This document defines a YANG module for the configuration and
management of A+P Softwire Customer Premises Equipment (CEs).
It covers Lightweight 4over6, MAP-E, and MAP-T mechanisms.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
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).
This version of this YANG module is part of RFC 8676; see
the RFC itself for full legal notices.";
revision 2019-11-16 {
description
"Initial revision.";
reference
"RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port
(A+P) Softwires";
}
/*
* Features
*/
feature binding-mode {
description
"Binding is used for configuring the Lightweight 4over6
mechanism.
Binding-based softwire mechanisms are IPv4-over-IPv6 tunneling
transition mechanisms specifically intended for complete
independence between the IPv6 subnet prefix (and IPv6 address)
and IPv4 address, with or without IPv4 address sharing.
This is accomplished by maintaining state for each softwire
(per-subscriber state) in the central Border Relay (BR) and
using a hub-and-spoke forwarding architecture. In order to
delegate the NAPT function and achieve IPv4 address sharing,
port-restricted IPv4 addresses needs to be allocated to CEs.
This feature indicates that the network element can function
as one or more binding-based softwire instances.";
reference
"RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack
Lite Architecture
RFC 7597: Mapping of Address and Port with Encapsulation
(MAP-E)
RFC 7599: Mapping of Address and Port using Translation
(MAP-T)";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state
using rules to express IPv4/IPv6 address mappings. This
introduces an algorithmic relationship between the IPv6
subnet and IPv4 address.
This feature indicates that the network element can function
as one or more MAP-E softwire instances.";
reference
"RFC 7597: Mapping of Address and Port with
Encapsulation (MAP-E)";
}
feature map-t {
description
"MAP-T is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP translation. It
leverages a double stateless NAT64-based solution as well as
the stateless algorithmic address and transport layer port
mapping algorithm defined for MAP-E.
This feature indicates that the network element can function
as one or more MAP-T softwire instances.";
reference
"RFC 7599: Mapping of Address and Port using Translation
(MAP-T)";
}
// Binding Entry
grouping binding-entry {
description
"The binding BR (Border Relay) maintains an address
binding table that contains the binding between the CE's
IPv6 address, the allocated IPv4 address, and the
restricted port-set.";
leaf binding-ipv6info {
type union {
type inet:ipv6-address;
type inet:ipv6-prefix;
}
description
"The IPv6 information for a binding entry.
When the IPv6 prefix type is used,
the IPv6 source address of the CE is constructed
according to the description in RFC 7596.
If the IPv6 address type is used, the CE can use
any valid /128 address from a prefix assigned to
the CE.";
reference
"RFC 7596: Lightweight 4over6: An Extension
to the Dual-Stack Lite Architecture, Section 5.1";
}
leaf br-ipv6-addr {
type inet:ipv6-address;
mandatory true;
description
"The IPv6 address of the binding BR.";
}
}
// configuration and stateful parameters for softwire CE interface
augment "/if:interfaces/if:interface" {
when "derived-from(if:type, 'iana-tunnel-type:aplusp')";
description
"Softwire CE interface configuration";
leaf softwire-payload-mtu {
type uint16;
units "bytes";
description
"The payload IPv4 MTU for the softwire tunnel.";
}
leaf softwire-path-mru {
type uint16;
units "bytes";
description
"The path MRU for the softwire (payload + encapsulation
overhead).";
reference
"RFC 4213: Basic Transition Mechanisms for IPv6 Hosts and
Routers";
}
choice ce-type {
description
"Sets the softwire CE mechanism";
case binding {
if-feature "binding-mode";
description
"CE binding configuration";
uses binding-entry;
}
case algo {
if-feature "map-e or map-t";
description
"CE algorithm configuration";
container algo-instances {
description
"Collection of MAP-E/MAP-T parameters";
list algo-instance {
key "name";
description
"MAP forwarding rule instance for
MAP-E/MAP-T";
leaf name {
type string;
mandatory true;
description
"The name is used to uniquely identify an algorithm
instance.
This name can be automatically assigned
or explicitly configured.";
}
uses softwire-common:algorithm-instance;
}
}
}
}
}
augment "/if:interfaces/if:interface/if:statistics" {
when "derived-from(../if:type, 'iana-tunnel-type:aplusp')";
description
"Softwire CE interface statistics.";
uses softwire-common:traffic-stat;
}
/*
* Notifications
*/
notification softwire-ce-event {
if-feature "binding-mode";
description
"CE notification";
leaf ce-binding-ipv6-addr-change {
type inet:ipv6-address;
mandatory true;
description
"This notification is generated whenever the CE's binding
IPv6 address changes for any reason.";
}
}
}
<CODE ENDS>7. BR Softwire YANG Module 🎀
this one is the BR side 💖 It imports typedefs from [RFC6991] and also grabs the 'ietf-softwire-common' module. Here's the start of it:
<CODE BEGINS> file "ietf-softwire-br@2019-11-16.yang"
module ietf-softwire-br {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-br";
prefix softwire-br;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types, Section 4";
}
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types, Section 3";
}
import ietf-softwire-common {
prefix softwire-common;
reference
"RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port
(A+P) Softwires";
}
organization
"IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwire@ietf.org>
Author: Qi Sun
<mailto:sunqi.ietf@gmail.com>
Author: Linhui Sun
<mailto:lh.sunlinh@gmail.com>
Author: Yong Cui
<mailto:yong@csnet1.cs.tsinghua.edu.cn>
Editor: Ian Farrer
<mailto:ian.farrer@telekom.de>
Author: Sladjana Zoric
<mailto:sladjana.zoric@telekom.de>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Rajiv Asati
<mailto:rajiva@cisco.com>";
description
"This document defines a YANG module for the configuration and
management of A+P Softwire Border Routers. It covers
Lightweight 4over6, MAP-E, and MAP-T mechanisms.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
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).
This version of this YANG module is part of RFC 8676; see
the RFC itself for full legal notices.";
revision 2019-11-16 {
description
"Initial revision.";
reference
"RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port
(A+P) Softwires";
}
/*
* Groupings
*/
grouping port-set {
description
"Describes a set of Layer 4 port numbers.okay so this is where the port-set stuff gets really fun 💅 the PSID gets you a whole range of ports, not just one, and it's giving math bestie 🧮✨
This may be a simple port range, or use the Port Set
Identifier (PSID) algorithm to represent a range of transport
layer ports that will be used by a NAPT.";
leaf psid-offset {
type uint8 {
range "0..16";
}
description
"The number of offset bits. In Lightweight 4over6,
the default value is 0 for assigning one contiguous
port range. In MAP-E/T, the default value is 6,
which means the system ports (0-1023) are excluded by
default and the assigned port ranges are distributed across
the entire port space, depending on either psid-len or the
number of contiguous ports.";
}
leaf psid-len {
type uint8 {
range "0..15";
}
mandatory true;
description
"The length of PSID, representing the sharing
ratio for an IPv4 address. This, along with ea-len, can
be used to calculate the number of contiguous ports per
port range";
}
leaf psid {
type uint16;
mandatory true;
description
"Port Set Identifier (PSID) value, which
identifies a set of ports algorithmically.";
}
}the binding-entry grouping is basically the BR's little address book 📒🫶 it links the CE's IPv6 info to its IPv4 address and its port-set, so everyone knows who's who 👑
grouping binding-entry {
description
"The binding BR maintains an address binding table that
contains the binding between the CE's IPv6 address,
the allocated IPv4 address and restricted port-set.";
leaf binding-ipv6info {
type union {
type inet:ipv6-address;
type inet:ipv6-prefix;
}
description
"The IPv6 information for a CE binding entry.
When the IPv6 prefix type is used,
the IPv6 source address of the CE is constructed
according to the description in RFC 7596;
if the IPv6 address type is used, the CE can use
any valid /128 address from a prefix assigned to
the CE.";
reference
"RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack
Lite Architecture";
}
leaf binding-ipv4-addr {
type inet:ipv4-address;
description
"The IPv4 address assigned to the binding CE,
which is used as the IPv4 external address
for binding CE local NAPT44.";
}
container port-set {
description
"For Lightweight 4over6, the default value
for offset should be 0, to configure one contiguous
port range.";
uses port-set {
refine "psid-offset" {
default "0";
}
}
}
leaf br-ipv6-addr {
type inet:ipv6-address;
description
"The IPv6 address for binding BR.";
}
}next up are the features 🎀 these are the on/off switches that say which softwire flavours a network element can actually do. binding-mode is the main character for Lightweight 4over6, and map-e and map-t are the MAP crew 🦋🌈
/*
* Features
*/
feature binding-mode {
description
"Binding is used for configuring the Lightweight 4over6
mechanism.
Binding-based softwire mechanisms are IPv4-over-IPv6 tunneling
transition mechanisms specifically intended for complete
independence between the IPv6 subnet prefix (and IPv6 address)
and IPv4 address, with or without IPv4 address sharing.
This is accomplished by maintaining state for each softwire
(per-subscriber state) in the central Border Relay (BR) and
using a hub-and-spoke forwarding architecture. In order to
delegate the NAPT function and achieve IPv4 address sharing,
port-restricted IPv4 addresses needs to be allocated to CEs.
This feature indicates that the network element can function
as one or more binding-based softwire instances.";
reference
"RFC 7596: Lightweight 4over6: An Extension to the Dual-Stack
Lite Architecture
RFC 7597: Mapping of Address and Port with Encapsulation
(MAP-E)
RFC 7599: Mapping of Address and Port using Translation
(MAP-T)";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state
using rules to express IPv4/IPv6 address mappings. This
introduces an algorithmic relationship between the IPv6 subnet
and IPv4 address.
This feature indicates that the network element can function
as one or more MAP-E softwire instances.";
reference
"RFC 7597: Mapping of Address and Port with Encapsulation
(MAP-E)";
}
feature map-t {
description
"MAP-T is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP translation. It
leverages a double stateless NAT64-based solution as well
as the stateless algorithmic address and transport layer
port mapping algorithm defined for MAP-E.
This feature indicates that the network element can function
as one or more MAP-T softwire instances.";
reference
"RFC 7599: Mapping of Address and Port using Translation
(MAP-T)";
}and now the br-instances container, which is where you set up the BR's binding or algorithmic instances. the version and date pair in the binding table is lowkey iconic, because it tells you which customer was which when someone reports abuse 🕵️♀️💀
container br-instances {
description
"BR instances enabled in a network element.";
choice br-type {
description
"Select binding or algorithmic BR functionality.";
case binding {
if-feature "binding-mode";
container binding {
description
"binding mechanism (binding table) configuration.";
list bind-instance {
key "name";
description
"A set of binding instances to be configured.";
leaf name {
type string;
mandatory true;
description
"The name for the binding BR. It is used to uniquely
distinguish a binding instance by its name.";
}
container binding-table-versioning {
description
"binding table's version";
leaf version {
type uint64;
description
"Version number for this binding table.";
}
leaf date {
type yang:date-and-time;
description
"Timestamp when the binding table was activated.
A binding instance may be provided with binding
entries that may change in time (e.g., increase
the size of the port set). When a party who is
the victim of abuse presents an external IP
address/port, the version of the binding table
is important because, depending on the version,
a distinct customer may be identified.Okay so we're picking up mid-description, bestie, and this part is all about the BR's binding table, its ICMP policy, and the stats 📊🎀 Look at softwire-num-max and enable-hairpinning too, they're doing a lot.
The timestamp is used as a key to find the
appropriate binding table that was put into effect
when an abuse occurred.";
reference
"RFC 7422: Deterministic Address Mapping to Reduce
Logging in Carrier-Grade NAT Deployments";
}
}
leaf softwire-num-max {
type uint32 {
range "1..max";
}
mandatory true;
description
"The maximum number of softwires that can be created
on the binding BR.";
}
leaf softwire-payload-mtu {
type uint16;
units "bytes";
mandatory true;
description
"The payload IPv4 MTU for binding softwire.";
}
leaf softwire-path-mru {
type uint16;
units "bytes";
mandatory true;
description
"The path MRU for binding softwire";
reference
"RFC 4213: Basic Transition Mechanisms for IPv6 Hosts
and Routers";
}
leaf enable-hairpinning {
type boolean;
default "true";
description
"Enables/disables support for locally forwarding
(hairpinning) traffic between two CEs";
reference
"RFC 7596: Lightweight 4over6: An Extension to
the Dual-Stack Lite Architecture, Section 6.2";
}
container binding-table {
description
"binding table";
list binding-entry {
key "binding-ipv6info";
description
"binding entry";
uses binding-entry;
}
}
container icmp-policy {
description
"The binding BR can be configured to process or drop
incoming ICMP messages and to generate outgoing ICMP
error messages.";
container icmpv4-errors {
description
"ICMPv4 error processing configuration";
leaf allow-incoming-icmpv4 {
type boolean;
default "true";
description
"Enables the processing of incoming ICMPv4
packets.";
reference
"RFC 7596: Lightweight 4over6: An Extension to
the Dual-Stack Lite Architecture";
}
leaf icmpv4-rate {
type uint32;
description
"Rate limit threshold in messages per second
for processing incoming ICMPv4 errors messages";
}
leaf generate-icmpv4-errors {
type boolean;
default "true";
description
"Enables the generation of outgoing ICMPv4 error
messages on receipt of an inbound IPv4 packet
with no matching binding table entry.";
reference
"RFC 7596: Lightweight 4over6:
An Extension to the Dual-Stack Lite
Architecture, Section 5.2";
}
}
container icmpv6-errors {
description
"ICMPv6 error processing configuration";
leaf generate-icmpv6-errors {
type boolean;
default "true";
description
"Enables the generation of ICMPv6 error messages
if no matching binding table entry is found for
a received packet.";
reference
"RFC 7596: Lightweight 4over6:
An Extension to the Dual-Stack Lite
Architecture, Section 6.2";
}
leaf icmpv6-rate {
type uint32;
description
"Rate limit threshold in messages per second
for sending ICMPv6 errors messages";
reference
"RFC 7596: Lightweight 4over6: An Extension
to the Dual-Stack Lite Architecture, Section 9";
}
}
}
container traffic-stat {
config false;
description
"Traffic statistics information for the BR.";
leaf discontinuity-time {
type yang:date-and-time;
mandatory true;
description
"The time of the most recent occasion on which the
BR instance suffered a discontinuity. This must
be initialized when the BR instance is configured
or rebooted.";
}
uses softwire-common:traffic-stat;
leaf dropped-icmpv4-packets {
type yang:zero-based-counter64;
description
"ICMPv4 packets that are dropped as a result
of the ICMP policy. Typically, this can be any
incoming ICMPv4 packets if ICMPv4 processing is
disabled or incoming ICMPv4 packets that exceed
the ICMPv4 rate-limit threshold.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf dropped-icmpv4-bytes {
type yang:zero-based-counter64;
description
"ICMPv4 messages, in bytes, that are dropped as
a result of the ICMP policy. Typically, it
can be any incoming ICMPv4 packets if ICMPv4
processing is disabled or incoming ICMPv4
packets that exceed the ICMPv4 rate-limit
threshold.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf hairpin-ipv4-packets {
type yang:zero-based-counter64;
description
"IPv4 packets locally routed between two CEs
(hairpinned).
Discontinuities in the value of this counter can
occur at re-initialization of the management
system and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf hairpin-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 bytes locally routed between two CEs
(hairpinned).
Discontinuities in the value of this counter can
occur at re-initialization of the management
system and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf active-softwire-num {
type uint32;
config false;
description
"The number of currently active softwires on the
binding instance.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system and at other times as indicated by
the value of 'discontinuity-time'.";
}
}
}
}
}
case algo {
if-feature "map-e or map-t";
container algorithm {
description
"A set of parameters used for MAP-E/MAP-T";
list algo-instance {
key "name";
description
"Instances of algorithm";
leaf name {
type string;
mandatory true;
description
"The name is used to uniquely identify an algorithm
instance.
This name can be automatically assigned
or explicitly configured.";
}
uses softwire-common:algorithm-instance;
container port-set {
description
"Indicates a set of ports.";
uses port-set;
}
container traffic-stat {
config false;
description
"Traffic statistics information for the BR.";
leaf discontinuity-time {
type yang:date-and-time;
mandatory true;
description
"The time of the most recent occasion on which the
BR instance suffered a discontinuity. This must
be reset to the current date-and-time when the BR
instance is configured or rebooted.";
}
uses softwire-common:traffic-stat;
}
}
}
}
}
}
/*
* Notifications
*/Quick tea ☕💖: the binding table is keyed by binding-ipv6info, and the algo case only shows up when map-e or map-t is turned on 🦋 ✨
notification softwire-binding-instance-event {
if-feature "binding-mode";
description
"Notifications for the binding instance when an entry is
added, modified, or is not valid anymore.";
leaf bind-name {
type leafref {
path "/br-instances/binding/bind-instance/name";
}
description
"The name of the binding-instance that
generated the notification.";
}
leaf-list invalid-entry {
type leafref {
path "/br-instances/binding/"
+ "bind-instance[name=current()/../bind-name]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description
"Notify the client that a specific binding entry has
expired or is invalid. The binding-ipv6info identifies
an entry.";
}
leaf-list added-entry {
type inet:ipv6-address;
description
"Notify the client that a binding entry has been added.
The IPv6 address of that entry is the index. The client
gets other information from the binding BR about the entry
indexed by that ipv6 address.";
}
leaf-list modified-entry {
type leafref {
path "/br-instances/binding/"
+ "bind-instance[name=current()/../bind-name]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description
"The binding table entry that has been modified.";
}
}
notification softwire-algorithm-instance-event {
if-feature "map-e or map-t";
description
"Notifications for an algorithm instance when an entry is
added, modified, or is not valid anymore.";
leaf algo-name {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
mandatory true;
description
"Algorithmic instance event.";
}
leaf-list invalid-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Invalid entry.";
}
leaf-list added-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Added entry.";
}
leaf-list modified-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Modified entry.";
}
}
}
<CODE ENDS>8. Common Softwire Element Groups YANG Module ✨
okay so this is the shared toolbox 🧰💖 Both the softwire CE and softwire BR modules pull from this one, so it's basically the group chat everyone reads. It imports typedefs from [RFC6991], and the definitions in here are used by both the softwire CE and softwire BR YANG modules. Iconic teamwork 🫶
<CODE BEGINS> file "ietf-softwire-common@2019-11-16.yang"
module ietf-softwire-common {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-common";
prefix softwire-common;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types, Section 4";
}
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types, Section 3";
}
organization
"IETF Softwire Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/softwire/>
WG List: <mailto:softwire@ietf.org>
Author: Qi Sun
<mailto:sunqi.ietf@gmail.com>
Author: Linhui Sun
<mailto:lh.sunlinh@gmail.com>
Author: Yong Cui
<mailto:yong@csnet1.cs.tsinghua.edu.cn>
Editor: Ian Farrer
<mailto:ian.farrer@telekom.de>
Author: Sladjana Zoric
<mailto:sladjana.zoric@telekom.de>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Rajiv Asati
<mailto:rajiva@cisco.com>";
description
"This document defines a YANG module defining types
common to all A+P modules.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
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).
This version of this YANG module is part of RFC 8676; see
the RFC itself for full legal notices.";
revision 2019-11-16 {
description
"Initial revision.";
reference
"RFC 8676: YANG Modules for IPv4-in-IPv6 Address plus Port
(A+P) Softwires";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state
using rules to express IPv4/IPv6 address mappings. This
introduces an algorithmic relationship between the IPv6
subnet and IPv4 address.
This feature indicates that the network element can function
as one or more MAP-E softwire instances.";
reference
"RFC 7597: Mapping of Address and Port with Encapsulation
(MAP-E)";
}
feature map-t {
description
"MAP-T is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP translation. It
leverages a double stateless NAT64-based solution as well as
the stateless algorithmic address and transport layer
port mapping algorithm defined for MAP-E.
This feature indicates that the network element can function
as one or more MAP-T softwire instances.";
reference
"RFC 7599: Mapping of Address and Port using Translation
(MAP-T)";
}
/*
* Groupings
*/
grouping algorithm-instance {
description
"A collection of parameters that is used for MAP-E/MAP-T.";
leaf enable {
type boolean;
description
"Enable/disable an individual MAP-E or MAP-T rule.";
}
container algo-versioning {
description
"Version number for this algorithm instance";
leaf version {
type uint64;
description
"A version number for the mapping algorithm
rules provided to the algorithm instance";
}
leaf date {
type yang:date-and-time;
description
"Timestamp when the algorithm instance was activated.
An algorithm instance may be provided with mapping
rules that may change in time (for example, increase
the size of the port set). When a party who is the victim
of abuse presents an external IP address/port, the version
of the algorithm is important because depending on
the version, a distinct customer may be identified.
The timestamp is used as a key to find the appropriate
algorithm that was put into effect when an abuse
occurred.";
reference
"RFC 7422: Deterministic Address Mapping to Reduce
Logging in Carrier-Grade NAT Deployments";
}
}
choice data-plane {
description
"Selects MAP-E (encapsulation) or MAP-T
(translation)";
case encapsulation {
if-feature "map-e";
description
"encapsulation for MAP-E";
leaf br-ipv6-addr {
type inet:ipv6-address;
mandatory true;
description
"The IPv6 address of the MAP-E BR.";
}
}
case translation {
if-feature "map-t";
description
"translation for MAP-T";
leaf dmr-ipv6-prefix {
type inet:ipv6-prefix;
description
"The IPv6 prefix of the MAP-T BR.";
}
}
}
leaf ea-len {
type uint8;
mandatory true;
description
"Embedded Address (EA) bits are the IPv4 EA-bits in the IPv6
address identifying an IPv4 prefix/address (or part thereof)
or a shared IPv4 address (or part thereof) and a port-set
identifier. The length of the EA-bits is defined as part of
a MAP rule for a MAP domain.";
}
leaf rule-ipv6-prefix {
type inet:ipv6-prefix;
mandatory true;
description
"The Rule IPv6 prefix defined in the mapping rule.";
}
leaf rule-ipv4-prefix {
type inet:ipv4-prefix;
mandatory true;
description
"The Rule IPv4 prefix defined in the mapping rule.";
}
leaf forwarding {
type boolean;
mandatory true;
description
"This parameter specifies whether the rule may be used for
forwarding; if set, this rule is used as a Forwarding
Mapping Rule (FMR); if not set, this rule is a Basic
Mapping Rule (BMR) only and must not be used for
forwarding.";
}
}
grouping traffic-stat {
description
"Traffic statistics";
leaf sent-ipv4-packets {
type yang:zero-based-counter64;
description
"Number of decapsulated and forwarded IPv4 packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv4-bytes {
type yang:zero-based-counter64;
description
"Decapsulated/translated IPv4 traffic sent, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of encapsulated IPv6 packets sent.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv6-bytes {
type yang:zero-based-counter64;
description
"Encapsulated IPv6 traffic sent, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv4-packets {
type yang:zero-based-counter64;
description
"Number of IPv4 packets received.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 traffic received, in bytes. Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of IPv4-in-IPv6 packets received.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv6-bytes {
type yang:zero-based-counter64;
description
"IPv4-in-IPv6 traffic received, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-packets {
type yang:zero-based-counter64;
description
"Number of IPv4 packets dropped at the
Internet-facing interface.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 traffic dropped at the Internet-facing
interface, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of IPv4-in-IPv6 packets dropped.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv6-bytes {
type yang:zero-based-counter64;
description
"IPv4-in-IPv6 traffic dropped, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-fragments {
type yang:zero-based-counter64;
description
"Number of fragmented IPv4 packets dropped.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-fragment-bytes {
type yang:zero-based-counter64;
description
"Fragmented IPv4 traffic dropped, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf ipv6-fragments-reassembled {
type yang:zero-based-counter64;
description
"Number of IPv6 fragments successfully reassembled.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf ipv6-fragments-bytes-reassembled {
type yang:zero-based-counter64;
description
"IPv6 fragments successfully reassembled, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv4-error-packets {
type yang:zero-based-counter64;
description
"Internally generated ICMPv4 error packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv4-error-bytes {
type yang:zero-based-counter64;
description
"Internally generated ICMPv4 error messages, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv6-error-packets {
type yang:zero-based-counter64;
description
"Internally generated ICMPv6 error packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv6-error-bytes {
type yang:zero-based-counter64;
description
"Internally generated ICMPv6 error messages, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system and at
other times as indicated by the value of
'discontinuity-time'.";
}
}
}
<CODE ENDS>9. Security Considerations 💅
okay bestie, the YANG modules in this document are built to be accessed over network management protocols like NETCONF [RFC6241] or RESTCONF [RFC8040] 🫶. The lowest NETCONF layer is the secure transport layer, and the one that's mandatory to implement is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport there is TLS [RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341] is how you lock down which NETCONF or RESTCONF users can run which protocol operations and see which content 🔐. It's giving bouncer at the door.
Every data node in these YANG modules that can be created, modified, and deleted (that's config true, the default) is considered sensitive 🚨. Write operations (like edit-config) to those nodes without proper protection can seriously mess with network operations 💀. An attacker who is able to access the BR can pull off a bunch of attacks, like:
- Pointing
'br-ipv6-addr'on the CE at an illegitimate BR so it can intercept all the traffic a CE sends 👀. Illegitimately intercepting users' traffic is an attack with severe implications on privacy 😭. - Setting the MTU to a low value, which may increase the number of fragments (
'softwire-payload-mtu') 🧩. - Disabling hairpinning (aka setting
'enable-hairpinning'to'false') to stop CEs from talking to each other 🙅. - Cranking
'softwire-num-max'up to some arbitrary huge value, which a misbehaving user could use to DoS the binding BR by spinning up a massive number of softwires 💀. - Setting
'icmpv4-rate'or'icmpv6-rate'to a low value, which may lead to ICMP message handling getting deactivated 🥲. - Instructing the BR to install entries, which will then induce a DDoS attack through the notifications the BR generates 🌪️. This DDoS can be softened by defining a notification interval, but since that interval parameter can be disabled or set to a low value by the misbehaving entity, the same problem shows up again 😩.
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments, so it's important to control read access (e.g., via get, get-config, or notification) to them 🕵️. These subtrees and data nodes can be misused to track the activity of a host:
- the binding Table (
/br-instances/binding/bind-instance/binding-table) - the algorithm configuration (
/br-instances/algorithm/algo-instance/)
Security considerations related to lw4o6, MAP-T, and MAP-E are discussed in [RFC7596], [RFC7597], and [RFC7599] respectively 📚. And security considerations given in [RFC7950] apply here too 🫶.
10. IANA Considerations 🎀
IANA has assigned the following new tunnel type under the tunnelType subregistry of the "ifType Definitions" registry maintained in the SMI Numbers registry [TUNNELTYPE-IANA-REGISTRY]:
Decimal: 18
Name: aplusp
Description: A+P encapsulation
Reference: [RFC6346]IANA has registered the following in the "ns" subregistry within the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-softwire-ce
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-softwire-br
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-softwire-common
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.IANA has registered the following YANG modules in the "YANG Module Names" subregistry [RFC6020] within the "YANG Parameters" registry 🌈.
name: ietf-softwire-ce
namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-ce
prefix: softwire-ce
reference: RFC 8676
name: ietf-softwire-br
namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-br
prefix: softwire-br
reference: RFC 8676
name: ietf-softwire-common
namespace: urn:ietf:params:xml:ns:yang:ietf-softwire-common
prefix: softwire-common
reference: RFC 867611. References ✨
11.1. Normative References 📚
okay so these are the references the spec needs you to have read to actually implement it, bestie 🫶 no cap, they're load-bearing 🔥
- [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004,
https://www.rfc-editor.org/info/rfc3688. - [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010,
https://www.rfc-editor.org/info/rfc6020. - [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. - [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. - [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013,
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. - [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. Farrer, "Lightweight 4over6: An Extension to the Dual-Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, July 2015,
https://www.rfc-editor.org/info/rfc7596. - [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., Murakami, T., and T. Taylor, Ed., "Mapping of Address and Port with Encapsulation (MAP-E)", RFC 7597, DOI 10.17487/RFC7597, July 2015,
https://www.rfc-editor.org/info/rfc7597. - [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for Configuration of Softwire Address and Port-Mapped Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015,
https://www.rfc-editor.org/info/rfc7598. - [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., and T. Murakami, "Mapping of Address and Port using Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July 2015,
https://www.rfc-editor.org/info/rfc7599. - [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. - [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. - [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. - [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. - [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. - [RFC8675] Boucadair, M., Farrer, I., and R. Asati, "A YANG Data Model for Tunnel Interface Types", RFC 8675, DOI 10.17487/RFC8675, November 2019,
https://www.rfc-editor.org/info/rfc8675. - [TUNNELTYPE-IANA-REGISTRY] IANA, "Structure of Management Information (SMI) Numbers (MIB Module Registrations)",
https://www.iana.org/assignments/smi-numbers.
11.2. Informative References 💡
these ones are the extra reading 🌸 helpful background, not strictly required to build the thing, but I'd still read them, periodt ✨
- [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms for IPv6 Hosts and Routers", RFC 4213, DOI 10.17487/RFC4213, October 2005,
https://www.rfc-editor.org/info/rfc4213. - [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. - [RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to the IPv4 Address Shortage", RFC 6346, DOI 10.17487/RFC6346, August 2011,
https://www.rfc-editor.org/info/rfc6346. - [RFC7422] Donley, C., Grundemann, C., Sarawat, V., Sundaresan, K., and O. Vautrin, "Deterministic Address Mapping to Reduce Logging in Carrier-Grade NAT Deployments", RFC 7422, DOI 10.17487/RFC7422, December 2014,
https://www.rfc-editor.org/info/rfc7422. - [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. - [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. - [RFC8344] Bjorklund, M., "A YANG Data Model for IP Management", RFC 8344, DOI 10.17487/RFC8344, March 2018,
https://www.rfc-editor.org/info/rfc8344. - [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for Routing Management (NMDA Version)", RFC 8349, DOI 10.17487/RFC8349, March 2018,
https://www.rfc-editor.org/info/rfc8349. - [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. - [RFC8513] Boucadair, M., Jacquenet, C., and S. Sivakumar, "A YANG Data Model for Dual-Stack Lite (DS-Lite)", RFC 8513, DOI 10.17487/RFC8513, January 2019,
https://www.rfc-editor.org/info/rfc8513.
Appendix A. Configuration Examples 🎀
ooh, the fun part 🧚 these show how the softwire YANG modules actually get used to configure softwire elements, so let's go bestie 💅
A.1. Configuration Example for a lw4o6 BR Binding-Table 🦋
the lwAFTR keeps an address binding table, and each entry is a 3-tuple of:
- IPv6 Address for a single lwB4
- Public IPv4 Address
- Restricted port-set
this entry does two jobs, and they're both iconic 👑: it handles the IPv6 encapsulation of inbound IPv4 packets headed for the lwB4, AND it validates outbound IPv4-in-IPv6 packets coming from the lwB4 so they can be decapsulated 🫶
okay so let's look at an example lw4o6 binding table entry:
lwB4 Binding IPv6 Address: 2001:db8::1
lwB4 Binding IPv4 Address: 192.0.2.1
lwB4 PSID: 0x34
lwB4 PSID Length 8
BR IPv6 Address: 2001:db8:1::2and here's the matching configuration XML 🍓
<br-instances>
<binding>
<bind-instance>
<name>mybinding-instance</name>
<binding-table>
<binding-entry>
<binding-ipv6info>2001:db8::1</binding-ipv6info>
<binding-ipv4-addr>192.0.2.1</binding-ipv4-addr>
<port-set>
<psid>52</psid>
<psid-len>8</psid-len>
</port-set>
<br-ipv6-addr>2001:db8:1::2</br-ipv6-addr>
</binding-entry>
</binding-table>
<softwire-num-max>1024</softwire-num-max>
<softwire-path-mru>1540</softwire-path-mru>
<softwire-payload-mtu>1500</softwire-payload-mtu>
</bind-instance>
</binding>
</br-instances>Figure 3: lw4o6 Binding Table Configuration XML
A.2. Configuration Example for a MAP-E BR 🌈
a MAP-E BR gets configured with forward mapping rules for the CEs it serves. In this example (taken from [RFC7597], Appendix A, Example 2), you need these parameters:
- Rule IPv6 Prefix
- Rule IPv4 Prefix
- Rule EA-bit bit length
- IPv6 Address of MAP-BR
the mapping rule has two functions too 💖: figuring out the destination CE IPv6 address for encapsulating inbound IPv4 packets, and validating outbound IPv4-in-IPv6 packets received from the CE so they can be de-capsulated.
also the data plane transport type has to be set to encapsulation so MAP-E works, and forwarding needs to be turned on ✨
let's check out this example forwarding mapping rule:
Data plane: encapsulation
Rule IPv6 Prefix: 2001:db8::/40
Rule IPv4 Prefix: 192.0.2.0/24
Rule EA-bit Length: 16
BR IPv6 Address: 2001:db8:ffff::1and Figure 4 is the MAP-E BR configuration XML 🫧
<br-instances>
<algorithm>
<algo-instance>
<name>myalgo-instance</name>
<encapsulation>
<br-ipv6-addr>2001:db8:ffff::1</br-ipv6-addr>
</encapsulation>
<ea-len>16</ea-len>
<rule-ipv4-prefix>192.0.2.0/24</rule-ipv4-prefix>
<rule-ipv6-prefix>2001:db8::/40</rule-ipv6-prefix>
<forwarding>true</forwarding>
<port-set>
<psid-offset>6</psid-offset>
<psid-len>8</psid-len>
</port-set>
</algo-instance>
</algorithm>
</br-instances>Figure 4: MAP-E FMR Configuration XML
A.3. lw4o6 CE Configuration Example ✨
okay so this bit is all about configuring a lw4o6 CE, and there are XML examples for it 🎀 Routing and NAT44 get some love too, just for convenience 💅
Here's the setup we're working with:
- lwB4 Binding IPv6 Address:
2001:db8::1 - lwB4 Binding IPv4 Address:
192.0.2.1 - lwB4 PSID:
0x34 - lwB4 PSID Length:
8 - BR IPv6 Address:
2001:db8:1::2
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>lw4o6-wan</name>
<type>iana-tunnel-type:aplusp</type>
<br-ipv6-addr
xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-ce">
2001:db8:1::2
</br-ipv6-addr>
<binding-ipv6info
xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-ce">
2001:db8::1
</binding-ipv6info>
</interface>
</interfaces>
</config>Figure 5: lw4o6 CE Configuration XML
In Figure 5 the softwire tunnel gets its interface name, lw4o6-wan. That name is then used by the routing config for the IPv4 route, so the two pieces link up nicely 🦋 Figure 6 shows the CE's IPv4 routing, using the YANG module from [RFC8349] 🌸
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type>static</type>
<name>v4</name>
<static-routes>
<ipv4
xmlns="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicas\
t-routing">
<route>
<destination-prefix>0.0.0.0/0</destination-prefix>
<next-hop>
<outgoing-interface>lw4o6-wan</outgoing-interface>
</next-hop>
</route>
</ipv4>
</static-routes>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>Figure 6: lw4o6 CE Routing Configuration XML
Last but not least, Figure 7 is the CE's NAPT44 function, using the YANG module from [RFC8512] 🧚 It's giving full setup, with the pool, port set, mapping limits and mapping table all in one place 💖
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<nat xmlns="urn:ietf:params:xml:ns:yang:ietf-nat">
<instances>
<instance>
<id>1</id>
<policy>
<policy-id>1</policy-id>
<external-ip-address-pool>
<pool-id>1</pool-id>
<external-ip-pool>192.0.2.1</external-ip-pool>
</external-ip-address-pool>
<port-set-restrict>
<port-set-algo>
<psid-offset>6</psid-offset>
<psid-len>8</psid-len>
<psid>52</psid>
</port-set-algo>
</port-set-restrict>
<notify-pool-usage>
<pool-id>1</pool-id>
<high-threshold>80</high-threshold>
</notify-pool-usage>
</policy>
<mapping-limits>
<limit-per-protocol>
<protocol-id>1</protocol-id>
<limit>8</limit>
</limit-per-protocol>
<limit-per-protocol>
<protocol-id>6</protocol-id>
<limit>32</limit>
</limit-per-protocol>
<limit-per-protocol>
<protocol-id>17</protocol-id>
<limit>16</limit>
</limit-per-protocol>
</mapping-limits>
<mapping-table>
<mapping-entry>
<index>1</index>
<external-src-address>
192.0.2.1/32
</external-src-address>
<internal-src-address>
192.168.1.0/24
</internal-src-address>
<transport-protocol>6</transport-protocol>
</mapping-entry>
<mapping-entry>
<index>2</index>
<external-src-address>
192.0.2.1/32
</external-src-address>
<internal-src-address>
192.168.1.0/24
</internal-src-address>
<transport-protocol>17</transport-protocol>
</mapping-entry>
<mapping-entry>
<index>3</index>
<external-src-address>
192.0.2.1/32
</external-src-address>
<internal-src-address>
192.168.1.0/24
</internal-src-address>
<transport-protocol>1</transport-protocol>
</mapping-entry>
</mapping-table>
</instance>
</instances>
</nat>
</config>Figure 7: lw4o6 NAT Configuration XML
Acknowledgements 🙈
Huge shoutout to Lishan Li, Bert Wijnen, Giles Heron, Ole Troan, Andy Wingo, and Leo Tietz for their contributions to this work 🫶
Thanks to Sheng Jiang for the review 💜
Special thanks to Tom Petch and Martin Bjorklund for the detailed review and suggestions 👑
Contributors 🌈
The following individuals are co-authors:
Yong Cui
Tsinghua University
China
Phone: +86-10-6260-3059
Email: cuiyong@tsinghua.edu.cn
Qi Sun
Tsinghua University
China
Phone: +86-10-6278-5822
Email: sunqi.ietf@gmail.com
Linhui Sun
Tsinghua University
China
Phone: +86-10-6278-5822
Email: lh.sunlinh@gmail.com
Sladjana Zechlin
Deutsche Telekom AG
Germany
Email: sladjana.zechlin@telekom.de
Rajiv Asati
Cisco Systems, Inc.
United States of America
Email: Rajiva@cisco.com
Hao Wang
Tsinghua University
China
Phone: +86-10-6278-5822
Email: wangh13@mails.tsinghua.edu.cnAuthors' Addresses 💅
Ian Farrer (editor)
Deutsche Telekom AG
CTO-ATI, Landgrabenweg 151
53227 Bonn
Germany
Email: ian.farrer@telekom.deMohamed Boucadair (editor)
Orange
35000 Rennes
France
Email: mohamed.boucadair@orange.com📦 where this page comes from
- ietf: rfc8676 2019-11
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms