RFC 9903
A YANG Data Model for OSPF Segment Routing over the MPLS Data Plane
Abstract ✨
Okay so this doc is all about a YANG data model (basically a schema that tells you how to configure and read stuff on a router) for managing OSPF extensions for Segment Routing over the MPLS data plane. 🦋 It's giving "one schema for this exact combo," and I'm obsessed.
Part 1 of 8 💖
Title Block 📄
This is RFC 9903: A YANG Data Model for OSPF Segment Routing over the MPLS Data Plane 🎀, published by the Internet Engineering Task Force (IETF) in December 2025. It's a Standards Track doc, which means it's a real spec, not just a suggestion. The ISSN is 2070-1721. 👑
The authors are Y. Qu (Futurewei Technologies), A. Lindem (LabN Consulting, L.L.C.), J. Zhang (Juniper Networks), and I. Chen (Red Hat, Inc.). 🫶 The title block doesn't list anything it obsoletes or updates, so there's no older RFC it replaces or patches. ✨
Status of This Memo 📋
This is an Internet Standards Track document. 💅
It's a product of the Internet Engineering Task Force (IETF), and it represents the consensus of the IETF community. It got public review and was approved for publication by the Internet Engineering Steering Group (IESG). If you want more info on Internet Standards, check out Section 2 of RFC 7841. 🌸
You can find the current status of this doc, any errata, and how to give feedback at https://www.rfc-editor.org/info/rfc9903. 🦋
Copyright Notice ⚖️
Copyright (c) 2025 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're in effect on the publication date. Please actually read these, because they spell out your rights and restrictions for this doc. 🙈
Code Components pulled out of this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions. They come without warranty, as described in the Revised BSD License.
Table of Contents 🧚
1. Overview
1.1. Requirements Language
1.2. Tree Diagrams
2. Design of the YANG Module for OSPF MPLS Segment Routing
3. OSPF Segment Routing over MPLS YANG Module
4. Security Considerations
5. IANA Considerations
6. References
6.1. Normative References
6.2. Informative References
Appendix A. A Configuration Example
Appendix B. Full Tree Diagram
Acknowledgements
Authors' Addresses1. Overview 🌈
Okay so this doc defines a YANG data model [RFC7950] that can be used to manage OSPFv2 extensions for Segment Routing [RFC2328] [RFC8665] and OSPFv3 extensions for Segment Routing [RFC5340] [RFC8666] over the MPLS data plane. ✨ The model is an augmentation to the OSPF YANG data model [RFC9129], so it builds on top of that one. 🫶
1.1. Requirements Language 🔥
Here's the deal with the key words. "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document get interpreted as described in BCP 14 [RFC2119] [RFC8174]. But they only count when they show up in ALL CAPS, exactly as shown here. 💅
1.2. Tree Diagrams 🌳
This document uses the graphical representation of a data model as defined in [RFC8340]. 🦋
2. Design of the YANG Module for OSPF MPLS Segment Routing 🎀
The YANG data model in this document is one single YANG module, called ietf-ospf-sr-mpls. ✨ It includes OSPF Segment Routing extensions for the MPLS data plane for both OSPFv2 [RFC8665] and OSPFv3 [RFC8666]. 💖
The ietf-ospf-sr-mpls module needs support for the base Segment Routing module [RFC9020]. That base module defines the global Segment Routing configuration, and it doesn't depend on any specific routing protocol config. It also needs support for the OSPF base model [RFC9129], which defines the basic OSPF configuration and state. 🧚
The ietf-ospf-sr-mpls module defines two things. First, the data nodes you use to configure OSPF Segment Routing MPLS extensions. Second, the additions to OSPF Link State Advertisements (LSAs) that you need to support Segment Routing over MPLS (SR-MPLS). The OSPF configuration covers these bits:
- OSPF instance level configuration, imported from the
ietf-segment-routing-mplsYANG module. This includes the mapping server bindings and the per-protocol Segment Routing Global Block (SRGB). (See thesr-control-planegrouping [RFC9020].) - OSPF area level configuration. This turns on SR-MPLS on all interfaces and enables advertisement of SR-MPLS information in Link State Advertisements (LSAs). 🌸
- OSPF interface level configuration for Adjacency Segment Identifiers (Adj-SIDs). These map to specific neighbors on multi-access interfaces (OSPF interface type broadcast or Non-Broadcast Multi-Access (NBMA)). The adjacency-sid definitions are imported from the
ietf-segment-routing-mplsYANG module. (See theigp-interfacegrouping [RFC9020].) - OSPF interface level configuration for Topology Independent Loop-Free Alternative (TI-LFA) using the MPLS data plane. TI-LFA is described in [RFC9855]. 🔥
The read-only operational state additions for OSPFv2 LSAs include:
- OSPFv2 Extended Prefix Range TLV encodings [RFC8665], carried in the OSPF Extended Prefix Opaque LSA [RFC7684]. 💜
- OSPFv2 Prefix-SID Sub-TLV encodings [RFC8665], including the OSPF Extended Prefix TLV. That TLV is advertised in the OSPF Extended Prefix Opaque LSA [RFC7684]. 👑
- OSPFv2 SR-Algorithm, SID/Label Range TLV, SR Local Block TLV, and Segment Routing Mapping Server (SRMS) Preference TLV [RFC8665]. These get advertised in the OSPFv2 Router Information Opaque LSA [RFC7770]. 🦋
The read-only operational state additions for OSPFv3 LSAs include:
- OSPFv3 Extended Prefix Range TLV encodings [RFC8666] in the OSPFv3 E-Intra-Area-Prefix-LSA, E-Inter-Area-Prefix-LSA, E-AS-External-LSA, and E-Type-7-LSA [RFC8362]. ✨
- OSPFv3 Prefix-SID Sub-TLV encodings [RFC8666] in the OSPFv3 Intra-Area-Prefix TLV, Inter-Area-Prefix TLV, External-Prefix TLV [RFC8362], and OSPFv3 Extended Prefix Range TLV [RFC8666]. 🌈
- OSPFv3 Adj-SID Sub-TLV [RFC8666] in the OSPFv3 Router-Link TLV [RFC8362]. 🎀
- OSPFv3 LAN Adj-SID Sub-TLV [RFC8666] in the OSPFv3 Router-Link TLV [RFC8362]. 🫶
- OSPFv3 SR-Algorithm, SID/Label Range TLV, SR Local Block TLV, and SRMS Preference TLV [RFC8666]. These get advertised in the OSPFv3 Router Information LSA [RFC7770]. 💅
3. OSPF Segment Routing over MPLS YANG Module 🧚
[RFC4915], [RFC6991], [RFC8102], [RFC8294], [RFC8349], [RFC8665], [RFC8666], [RFC9020], [RFC9129], [RFC9587], and [RFC9855] are all referenced in the YANG module. 📚
Here's the module itself 👀:
<CODE BEGINS> file "ietf-ospf-sr-mpls@2025-12-09.yang"
module ietf-ospf-sr-mpls {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ospf-sr-mpls";
prefix ospf-sr-mpls;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import iana-routing-types {
prefix iana-rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import ietf-routing {
prefix rt;
reference
"RFC 8349: A YANG Data Model for Routing
Management (NMDA Version)";
}
import ietf-segment-routing-common {
prefix sr-cmn;
reference
"RFC 9020: YANG Data Model for Segment Routing";
}
import ietf-segment-routing-mpls {
prefix sr-mpls;
reference
"RFC 9020: YANG Data Model for Segment Routing";
}
import ietf-ospf {
prefix ospf;
reference
"RFC 9129: YANG Data Model for the OSPF Protocol";
}
import ietf-ospfv3-extended-lsa {
prefix ospfv3-e-lsa;
reference
"RFC 9587: YANG Data Model for OSPFv3 Extended LSAs";
}
organization
"IETF LSR - Link State Routing Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lsr/>
WG List: <mailto:lsr@ietf.org>
Author: Yingzhen Qu
<mailto:yingzhen.ietf@gmail.com>
Author: Acee Lindem
<mailto:acee.ietf@gmail.com>
Author: Jeffrey Zhang
<mailto:zzhang@juniper.net>
Author: Ing-Wher Chen
<mailto:ichen@redhat.com>";
description
"This YANG module defines the generic configuration
and operational state for OSPF Segment Routing (SR).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2025 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
All revisions of IETF and IANA published modules can be found
at the YANG Parameters registry
(https://www.iana.org/assignments/yang-parameters).
This version of this YANG module is part of RFC 9903; see
the RFC itself for full legal notices.";
revision 2025-12-09 {
description
"Initial revision.";
reference
"RFC 9903: A YANG Data Model for OSPF Segment Routing
over the MPLS Data Plane";
}
feature remote-lfa-sr {
description
"Enhance Remote Loop-Free Alternate (RLFA) to use an SR path.";
reference
"RFC 8102: Remote-LFA Node Protection and Manageability";
}
feature ti-lfa {
description
"Topology Independent Loop-Free Alternate (TI-LFA)
computation using Segment Routing.";
reference
"RFC 9855: Topology Independent Fast Reroute Using Segment
Routing";
}
identity prefix-sid-flag {
description
"Base identity for Prefix-SID Sub-TLV flags.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}
identity np-flag {
base prefix-sid-flag;
description
"No-PHP (No Penultimate Hop-Popping) flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}
identity m-flag {
base prefix-sid-flag;
description
"Mapping server flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}
identity e-flag {
base prefix-sid-flag;
description
"Explicit-NULL flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}Okay bestie, the flags come first 💖 Each one is a little identity with a base, a description, and references back to the OSPF SR specs 🦋
identity v-flag {
base prefix-sid-flag;
description
"Value/Index flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}
identity l-flag {
base prefix-sid-flag;
description
"Local flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
}
identity extended-prefix-range-flag {
description
"Base identity for Extended Prefix Range TLV flags.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 4
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
}
identity ia-flag {
base extended-prefix-range-flag;
description
"Inter-Area flag. Note that this is only applicable to OSPFv2
since OSPFv3 advertises separate Inter-Area extended-LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 4";
}The ia-flag one is extra specific: it only applies to OSPFv2 🙈 OSPFv3 uses separate Inter-Area extended-LSAs instead, so don't go looking for it there 💅
identity adj-sid-flag {
description
"Base identity for Adj-SID Sub-TLV flags.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}
identity b-flag {
base adj-sid-flag;
description
"Backup flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}
identity vi-flag {
base adj-sid-flag;
description
"Value/Index flag - corresponds to V-Flag in references.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}
identity lg-flag {
base adj-sid-flag;
description
"Local/Global flag - corresponds to L-Flag in references.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}
identity g-flag {
base adj-sid-flag;
description
"Group flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}
identity p-flag {
base adj-sid-flag;
description
"Persistent flag.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
}The Adj-SID flags are the whole squad 👑 The vi-flag and lg-flag are just the V-Flag and L-Flag from the references, with new names so the module can use them ✨
Next up are the groupings, which are the reusable building blocks of the module 🧚 The big one is the SID encoding, since a SID can be a 20-bit label or a 32-bit index depending on the TLV length and the V and L flags 🔥
/* Groupings */
grouping sid-tlv-encoding {
description
"SID TLV Encoding - 20-bit label or 32-bit SID index whose
interpretation is dependent on the TLV length (3 for an
MPLS label or 4 for a 32-bit value) or the TLV V-Flag and
L-Flag settings:
If the V-Flag is set to 0 and L-Flag is set to 0:
The SID/Index/Label field is a 4-octet index defining
the offset in the SID/Label space advertised by this
router.
If the V-Flag is set to 1 and L-Flag is set to 1:
The SID/Index/Label field is a 3-octet local label where the
20 rightmost bits are used for encoding the label value.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 2.1
RFC 8665: OSPF Extensions for Segment Routing, Section 5
RFC 8666: OSPFv3 Extensions for Segment Routing, Section 3";
choice sid {
case sid-label {
leaf label-value {
type uint32 {
range "0 .. 1048575";
}
description
"A 20-bit MPLS label.";
}
}
case sid-index {
leaf index-value {
type uint32;
description
"Index into a label space advertised by this router.";
}
}
description
"Choice of either a 20-bit MPLS label or 32-bit index into
an advertised label space.";
}
}So sid-tlv-encoding is a choice between a label-value (range 0 .. 1048575, which is the 20-bit space) and an index-value 🦋 The V and L flag combos decide which one you're looking at, and the spec spells out both cases in the description above 💜
grouping ospfv2-prefix-sid-sub-tlvs {
description
"OSPFv2 Prefix Segment ID (SID) Sub-TLVs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5";
container prefix-sid-sub-tlvs {
description
"Prefix-SID Sub-TLV.";
list prefix-sid-sub-tlv {
description
"Prefix-SID Sub-TLV.";
container prefix-sid-flags {
leaf-list flag {
type identityref {
base prefix-sid-flag;
}
description
"Prefix-SID Sub-TLV flags.";
}
description
"SID flags.";
}
leaf mt-id {
type uint8 {
range "0 .. 127";
}
description
"Multi-topology ID.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF";
}
leaf algorithm {
type identityref {
base sr-cmn:prefix-sid-algorithm;
}
description
"Algorithm associated with the Prefix-SID.";
}
uses sid-tlv-encoding;
}
}
}The Prefix-SID grouping is where the flags, the multi-topology ID, the algorithm, and the SID encoding all come together 🎀 It's giving complete package ✨
grouping ospfv2-extended-prefix-range-tlvs {
description
"OSPFv2 Extended Prefix Range TLV grouping.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 4";
container extended-prefix-range-tlvs {
description
"List of prefix ranges.";
list extended-prefix-range-tlv {
description
"Range of prefixes.";
leaf prefix-length {
type uint8;
description
"Length of prefix in bits.";
}
leaf af {
type iana-rt-types:address-family;
description
"Address family for the prefix.";
}
leaf range-size {
type uint16;
description
"Number of prefixes covered by the
advertisement.";
}
container extended-prefix-range-flags {
leaf-list flag {
type identityref {
base extended-prefix-range-flag;
}
description
"Extended Prefix Range TLV flags.";
}
description
"Extended Prefix Range TLV flags.";
}
leaf prefix {
type inet:ipv4-prefix;
description
"IPv4 prefix.";
}
uses ospfv2-prefix-sid-sub-tlvs;
uses ospf:unknown-tlvs;
}
}
}The Extended Prefix Range one is a whole range of prefixes in a single advertisement 🌈 It has its own prefix length, address family, range size and flags, then pulls in the Prefix-SID sub-TLVs and any unknown TLVs 🙈
grouping ospfv2-adj-sid-sub-tlvs {
description
"OSPFv2 Adj-SID Sub-TLV grouping.";
container adj-sid-sub-tlvs {
description
"Adj-SID optional sub-TLVs.";
list adj-sid-sub-tlv {
description
"List of Adj-SID Sub-TLVs.";
container adj-sid-flags {
leaf-list flag {
type identityref {
base adj-sid-flag;
}
description
"Adj-SID Sub-TLV flags.";
}
description
"Adj-SID Sub-TLV flags.";
}
leaf mt-id {
type uint8 {
range "0 .. 127";
}
description
"Multi-topology ID. Topologies range from 0-127 and
return of any other value would indicate an error.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF";
}
leaf weight {
type uint8;
description
"Weight used for load-balancing.";
}
uses sid-tlv-encoding;
}
}
}Adj-SID is the adjacency version, with a weight for load-balancing and the same multi-topology ID checks 🍓 Anything outside 0-127 in that mt-id is flagged as an error in the description, so keep an eye on it 👀
grouping ospfv2-lan-adj-sid-sub-tlvs {
description
"OSPFv2 LAN Adj-SID Sub-TLV grouping.";
container lan-adj-sid-sub-tlvs {
description
"LAN Adj-SID optional sub-TLVs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6";
list lan-adj-sid-sub-tlv {
description
"List of LAN Adj-SID Sub-TLVs.";
container lan-adj-sid-flags {
leaf-list flag {
type identityref {
base adj-sid-flag;
}
description
"LAN Adj-SID Sub-TLV flags.";
}
description
"LAN Adj-SID Sub-TLV flags.";
}
leaf mt-id {
type uint8 {
range "0 .. 127";
}
description
"Multi-topology ID. Topologies range from 0-127 and
return of any other value would indicate an error.";
reference
"RFC 4915: Multi-Topology (MT) Routing in OSPF";
}
leaf weight {
type uint8;
description
"Weight used for load-balancing.";
}
leaf neighbor-router-id {
type rt-types:router-id;
description
"Neighbor router ID.";
}
uses sid-tlv-encoding;
}
}
}The LAN version is basically the Adj-SID plus a neighbor-router-id so you know which neighbour on the LAN it's for 🫶 Same mt-id rules apply, so no sneaking in values past 127 🙅♀️
grouping sr-algorithm-tlv {
description
"SR-Algorithm TLV grouping.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3.1";
container sr-algorithm-tlv {
description
"All SR-Algorithm TLVs.";
leaf-list sr-algorithm {
type identityref {
base sr-cmn:prefix-sid-algorithm;
}
description
"Segment Routing (SR) algorithms that the router is
currently using.";
}
}
}The SR-Algorithm grouping is the simple one: a leaf-list of the algorithms the router is currently using 💅
grouping sid-range-tlvs {
description
"SID Range TLV grouping.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3.2";
container sid-range-tlvs {
description
"List of SID Range TLVs.";
list sid-range-tlv {
description
"SID Range TLV.";
leaf range-size {
type rt-types:uint24;
description
"SID range. The return of a zero value would indicate
an error.";
}
uses sid-tlv-encoding;
}
}
}SID Range is where a range size comes in as a uint24, and a zero there counts as an error 🙈 Again it reuses the same SID encoding, so the whole thing stays consistent ✨
grouping local-block-tlvs {
description
"The SR Local Block TLV contains the
range of labels reserved for local SIDs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3.3";
container local-block-tlvs {
description
"List of Segment Routing Local Block (SRLB) TLVs.";
list local-block-tlv {
description
"SRLB TLV.";
leaf range-size {
type rt-types:uint24;
description
"SID range. The return of a zero value would indicate
an error.";
}
uses sid-tlv-encoding;
}
}
}And the Local Block one is the range of labels reserved for local SIDs 🧚 It's built the same way as SID Range, so the same zero-means-error rule applies here too 🌸
Okay bestie, this part is where the SRMS preference lives 🧚 The TLV is about which mapping server is the fave 💅 Higher number means more preferred, periodt.
grouping srms-preference-tlv {
description
"The Segment Routing Mapping Server (SRMS) Preference TLV is
used to advertise a preference associated with the node that
acts as an SRMS. SRMS advertisements with a higher
preference value are preferred over those with a lower
preference value.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3.4";
container srms-preference-tlv {
description
"SRMS Preference TLV.";
leaf preference {
type uint8;
description
"SRMS Preference TLV, value from 0 to 255 with
255 being the most preferred.";
}
}
}Next up is the OSPFv3 Prefix-SID sub-TLVs 🦋 This is where each prefix gets its SID, plus flags, an algorithm, and the usual SID encoding bits. So much detail, I'm obsessed 😭
grouping ospfv3-prefix-sid-sub-tlvs {
description
"OSPFv3 Prefix-SID Sub-TLVs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
container prefix-sid-sub-tlvs {
description
"Prefix-SID Sub-TLV.";
list prefix-sid-sub-tlv {
description
"Prefix-SID Sub-TLV.";
container ospfv3-prefix-sid-flags {
leaf-list flag {
type identityref {
base prefix-sid-flag;
}
description
"Prefix-SID Sub-TLV flags.";
}
description
"SID flags.";
}
leaf algorithm {
type identityref {
base sr-cmn:prefix-sid-algorithm;
}
description
"Algorithm associated with the Prefix-SID.";
}
uses sid-tlv-encoding;
}
}
}Now the Extended Prefix Range TLVs 🌸 This one lets you cover a whole range of prefixes in one go, with a size and an address family. A zero range size is called out as an error, so keep that in mind 🙈
grouping ospfv3-extended-prefix-range-tlvs {
description
"OSPFv3 Extended Prefix Range TLV grouping.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
container ospfv3-extended-prefix-range-tlvs {
description
"List of Extended Prefix Range TLVs.";
list extended-prefix-range-tlv {
description
"Range of prefixes.";
leaf prefix-length {
type uint8;
description
"Length of prefix in bits.";
}
leaf af {
type iana-rt-types:address-family;
description
"Address family for the prefix.";
}
leaf range-size {
type uint16;
description
"Number of prefixes covered by the advertisement.
The return of a value of zero would indicate an error.";
}
leaf prefix {
type inet:ip-prefix;
description
"IPv4 or IPv6 prefix.";
}
uses ospfv3-prefix-sid-sub-tlvs;
uses ospf:unknown-tlvs;
}
}
}Adj-SIDs come next 🔥 These are the adjacency SIDs, with flags, a weight for load-balancing, and the same SID encoding bits as before.
grouping ospfv3-adj-sid-sub-tlvs {
description
"OSPFv3 Adj-SID Sub-TLV grouping.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
container adj-sid-sub-tlvs {
description
"Adj-SID optional sub-TLVs.";
list adj-sid-sub-tlv {
description
"List of Adj-SID Sub-TLVs.";
container adj-sid-flags {
leaf-list flag {
type identityref {
base adj-sid-flag;
}
description
"Adj-SID Sub-TLV flags.";
}
description
"Adj-SID Sub-TLV flags.";
}
leaf weight {
type uint8;
description
"Weight used for load-balancing.";
}
uses sid-tlv-encoding;
}
}
}LAN Adj-SIDs are the broadcast-network cousin 🫶 Same vibe, plus a neighbor router ID so you know exactly who you're talking to.
grouping ospfv3-lan-adj-sid-sub-tlvs {
description
"OSPFv3 LAN Adj-SID Sub-TLV grouping.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
container lan-adj-sid-sub-tlvs {
description
"LAN Adj-SID optional sub-TLVs.";
list lan-adj-sid-sub-tlv {
description
"List of LAN Adj-SID Sub-TLVs.";
container lan-adj-sid-flags {
leaf-list flag {
type identityref {
base adj-sid-flag;
}
description
"LAN Adj-SID Sub-TLV flags.";
}
description
"LAN Adj-SID Sub-TLV flags.";
}
leaf weight {
type uint8;
description
"Weight used for load-balancing.";
}
leaf neighbor-router-id {
type rt-types:router-id;
description
"Neighbor router ID.";
}
uses sid-tlv-encoding;
}
}
}Now the augmentations 👑 These are the read-write config bits that bolt SR-MPLS onto OSPF. Time to see where each one attaches.
/*
* Augmentations for OSPF SR-MPLS Configuration (read-write)
* data nodes.
*/
augment "/rt:routing/rt:control-plane-protocols"
+ "/rt:control-plane-protocol/ospf:ospf" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf')" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments the OSPF protocol configuration with Segment
Routing over the MPLS data plane. The following semantic
validation is to be performed for the configuration data:
- Assure prefixes specified in binding policies do not
overlap.";
reference
"RFC 9020: YANG Data Model for Segment Routing";
uses sr-mpls:sr-control-plane;
container protocol-srgb {
if-feature "sr-mpls:protocol-srgb";
uses sr-cmn:srgb;
description
"Per-protocol SRGB.";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf') and "
+ "/rt:routing/rt:control-plane-protocols"
+ "/rt:control-plane-protocol/ospf:ospf"
+ "/ospf-sr-mpls:segment-routing/"
+ "ospf-sr-mpls:enabled = 'true'" {
description
"This augments the OSPF area configuration when Segment
Routing is enabled at the OSPF instance level.";
}
container segment-routing {
presence "When present, SR-MPLS is enabled
for the area.";
description
"OSPF area level Segment Routing configuration. Enables
SR-MPLS on all interfaces, and enables advertisement of
Link State Advertisements (LSAs) and TLVs supporting
SR-MPLS.";
}
description
"This augments the OSPF protocol area configuration with
Segment Routing.";
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area/ospf:interfaces/ospf:interface" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf') and "
+ "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area/ospf-sr-mpls:segment-routing" {
description
"This augments the OSPF interface configuration when used.";
}
description
"This augments the OSPF protocol interface
configuration with Segment Routing.";
reference
"RFC 9020: YANG Data Model for Segment Routing";
uses sr-mpls:igp-interface {
augment "segment-routing/adjacency-sid/adj-sids" {
when "((../../../ospf:interface-type = 'broadcast') or
(../../../ospf:interface-type = 'non-broadcast'))" {
description
"This augments broadcast and non-broadcast multi-access
interface with Segment Routing interface
configuration.";
}
description
"This augments multi-access interface adj-sids with a
neighbor-id.";
leaf neighbor-id {
type inet:ip-address;
mandatory true;
description
"Neighbor's Router ID, IPv4 address, or IPv6 address.
Specification is optional and, if specified, SHOULD
specify a neighbor reachable via the interface.";
}
}
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area/ospf:interfaces/ospf:interface/"
+ "ospf:fast-reroute/ospf:lfa" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf')" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments the OSPF protocol IP Fast Reroute (IP-FRR) with
TI-LFA.";
container ti-lfa {
if-feature "ti-lfa";
description
"Topology Independent Loop Free Alternate
(TI-LFA) support.";
reference
"RFC 9855: Topology Independent Fast Reroute Using Segment
Routing";
leaf enabled {
type boolean;
default "false";
description
"Enable TI-LFA computation.";
}
container selection-tie-breakers {
container node-protection {
presence "Presence of container enables the node
protection tie-breaker.";
leaf priority {
type uint8;
default "128";
description
"Priority for node protection tie-breaker with
a lower priority being more preferred. By default,
the priority is in the middle of the priority range.";
}
description
"Enable node protection as a TI-LFA path
selection tie-breaker. A path providing node
protection will be selected over one that
doesn't provide node protection.";
}
container srlg-disjoint {
presence "Presence of container enables the SRLG
disjoint tie-breaker.";
leaf priority {
type uint8;
default "128";
description
"Priority for Shared Risk Link Group (SRLG)
disjoint tie-breaker with a lower priority being
more preferred. By default, the priority is in the
middle of the priority range.";
}
description
"Enable SRLG disjoint as a TI-LFA path selection
tie-breaker. A path providing a node with a disjoint
path for SRLG links from the primary path will be
selected over a path that doesn't provide an SRLG
disjoint path.";
}
description
"Configure path selection tie-breakers and their
respective priorities for the TI-LFA computation.
Multiple tie-breakers and priorities may be configured.";
}
}
}okay bestie, this is where the YANG augments start stacking up like a fresh fit 💅✨ we're adding SR bits onto OSPF without breaking the base module 🦋
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area/ospf:interfaces/ospf:interface/"
+ "ospf:fast-reroute/ospf:lfa/ospf:remote-lfa" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf')" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments the OSPF protocol IP-FRR with RLFA.";
reference
"RFC 9855: Topology Independent Fast Reroute Using Segment
Routing";
leaf use-segment-routing-path {
if-feature "remote-lfa-sr";
type boolean;
default "false";
description
"Force RLFA to use a Segment Routing path instead of an
LDP path. The value of this leaf is in effect only when
remote-lfa is enabled.";
}
}
/* Operational states */
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/ospf:ospf/"
+ "ospf:areas/ospf:area/ospf:interfaces/ospf:interface/"
+ "ospf:neighbors/ospf:neighbor" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospf')" {
description
"This augments the OSPF routing protocol when used.";
}
description
"This augments the OSPF interface adjacency-sid state.";
list adjacency-sid {
description
"List of Adj-SIDs.";
leaf value {
type uint32;
description
"Value of the Adj-SID.";
}
leaf weight {
type uint8;
description
"Weight associated with the Adj-SID.";
}
leaf protection-requested {
type boolean;
description
"Indicate if the Adj-SID is protected.";
}
}
}
/*
* Augmentations for read-only data nodes corresponding to Segment
* Routing encodings in OSPFv2 and OSPFv3 Link State Advertisements
* (LSAs) in OSPF Link State Databases (LSDBs) at the instance,
* area, and interface level.
*/
/* Augmentations for OSPFv2 LSAs. */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR Extended Prefix Range TLV in OSPFv2 Type 10 (area-scoped)
Extended Prefix Opaque LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 4";
uses ospfv2-extended-prefix-range-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR Extended Prefix Range TLV in OSPFv2 Type 11 (AS-scoped)
Extended Prefix Opaque LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 4";
uses ospfv2-extended-prefix-range-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR Prefix-SID Sub-TLVs for OSPFv2 Extended Prefix TLVs
in OSPFv2 Type 10 (area-scoped) Extended Prefix Opaque LSAs.";
uses ospfv2-prefix-sid-sub-tlvs;
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5";
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR Prefix-SID Sub-TLVs for OSPFv2 Extended Prefix TLVs
in OSPFv2 Type 11 (AS-scoped) Extended Prefix Opaque LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 5";
uses ospfv2-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/"
+ "ospf:extended-link-opaque/ospf:extended-link-tlv" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR TLVs for OSPFv2 Extended Link TLV in OSPFv2 Type 10
(area-scoped) Extended Link Opaque LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 6";
uses ospfv2-adj-sid-sub-tlvs;
uses ospfv2-lan-adj-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR TLVs for OSPFv2 Router Information Type 10 (area-scoped)
Opaque LSAs";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3";
uses sr-algorithm-tlv;
uses sid-range-tlvs;
uses local-block-tlvs;
uses srms-preference-tlv;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv2/"
+ "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv2')" {
description
"This augmentation is only valid for OSPFv2.";
}
description
"SR TLVs for OSPFv2 Router Information Type 11 (AS-scoped)
Opaque LSAs.";
reference
"RFC 8665: OSPF Extensions for Segment Routing, Section 3";
uses sr-algorithm-tlv;
uses sid-range-tlvs;
uses local-block-tlvs;
uses srms-preference-tlv;
}
/* Augmentations for OSPFv3 LSAs. */
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR-specific TLVs for OSPFv3 Router Information LSA
(area-scoped).";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 4";
uses sr-algorithm-tlv;
uses sid-range-tlvs;
uses local-block-tlvs;
uses srms-preference-tlv;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/"
+ "ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospf:router-information" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR-specific TLVs for OSPFv3 Router Information LSA
(AS-scoped).";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 4";
uses sr-algorithm-tlv;
uses sid-range-tlvs;
uses local-block-tlvs;
uses srms-preference-tlv;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-intra-area-prefix" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
uses ospfv3-extended-prefix-range-tlvs;
description
"SR Extended Prefix Range TLVs in OSPFv3
E-Intra-Area-Prefix LSAs.";
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-prefix" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Extended Prefix Range TLVs in OSPFv3
E-Inter-Area-Prefix LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
uses ospfv3-extended-prefix-range-tlvs;
} augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Extended Prefix Range TLVs in OSPFv3 E-AS-External LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
uses ospfv3-extended-prefix-range-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-nssa" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Extended Prefix Range TLVs in OSPFv3 E-NSSA LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
uses ospfv3-extended-prefix-range-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:interfaces/"
+ "ospf:interface/"
+ "ospf:database/ospf:link-scope-lsa-type/"
+ "ospf:link-scope-lsas/ospf:link-scope-lsa/"
+ "ospf:version/ospf:ospfv3/ospf:ospfv3/"
+ "ospf:body/ospfv3-e-lsa:e-link/"
+ "ospfv3-e-lsa:e-link-tlvs/ospfv3-e-lsa:intra-prefix-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Prefix-SID Sub-TLV in OSPFv3 Intra-Area-Prefix
TLV for OSPFv3 E-Link LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
uses ospfv3-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-intra-area-prefix/"
+ "ospfv3-e-lsa:e-intra-prefix-tlvs/"
+ "ospfv3-e-lsa:intra-prefix-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3
E-Router LSAs.";
}
description
"SR Prefix-SID Sub-TLV in OSPFv3 Intra-Area-Prefix
TLV for OSPFv3 E-Intra-Area-Prefix LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
uses ospfv3-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-inter-area-prefix/"
+ "ospfv3-e-lsa:e-inter-prefix-tlvs/"
+ "ospfv3-e-lsa:inter-prefix-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Prefix-SID Sub-TLV in OSPFv3 Intra-Area-Prefix
TLV for OSPFv3 E-Inter-Area-Prefix LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
uses ospfv3-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:database/"
+ "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
+ "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external/"
+ "ospfv3-e-lsa:e-external-tlvs/"
+ "ospfv3-e-lsa:external-prefix-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Prefix-SID Sub-TLV in OSPFv3 External-Prefix TLV
for OSPFv3 E-AS-External LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
uses ospfv3-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-nssa/"
+ "ospfv3-e-lsa:e-external-tlvs/"
+ "ospfv3-e-lsa:external-prefix-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3.";
}
description
"SR Prefix-SID Sub-TLV in OSPFv3 External-Prefix TLV
for OSPFv3 E-NSSA LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 6";
uses ospfv3-prefix-sid-sub-tlvs;
}
augment "/rt:routing/"
+ "rt:control-plane-protocols/rt:control-plane-protocol/"
+ "ospf:ospf/ospf:areas/ospf:area/ospf:database/"
+ "ospf:area-scope-lsa-type/ospf:area-scope-lsas/"
+ "ospf:area-scope-lsa/ospf:version/ospf:ospfv3/"
+ "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router/"
+ "ospfv3-e-lsa:e-router-tlvs/ospfv3-e-lsa:link-tlv/"
+ "ospfv3-e-lsa:sub-tlvs" {
when "derived-from(/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:type, 'ospf:ospfv3')" {
description
"This augmentation is only valid for OSPFv3
E-Router LSAs.";
}
description
"SR Sub-TLVs in OSPFv3 Router-Link TLV for OSPFv3 E-Router
LSAs.";
reference
"RFC 8666: OSPFv3 Extensions for Segment Routing, Section 7";
uses ospfv3-adj-sid-sub-tlvs;
uses ospfv3-lan-adj-sid-sub-tlvs;
}
}
<CODE ENDS>Figure 1
4. Security Considerations 💀
okay so this section is modeled after the template in Section 3.7 of [YANG-GUIDE], bestie 🎀 we're sticking to the house style so everything lines up.
The ietf-ospf-sr-mpls YANG module is built to be accessed through YANG-based management protocols, like NETCONF [RFC6241] and RESTCONF [RFC8040]. These protocols (1) have to use a secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) and (2) have to use mutual authentication. no cap, this part is not optional 🫶
The Network Configuration Access Control Model (NACM) [RFC8341] gives you the tools to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. it's giving access control realness ✨
There are a bunch of data nodes in this module that are writable, creatable, and deletable (i.e., config true, which is the default). All writable data nodes are likely to be sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) and delete operations to these data nodes without proper protection or authentication can have a negative effect on network operations. The following subtrees and data nodes have particular sensitivities/vulnerabilities:
/ospf:ospf/segment-routing/enabled- Modification to the enablement for SR could result in a Denial-of-Service (DoS) attack. If an attacker disables SR, it will cause traffic disruption. 😭/ospf:ospf/segment-routing/bindings- Modification to the local bindings could result in a DoS attack./ospf:ospf/protocol-srgb- Modification of the protocol SRGB could be used to mount a DoS attack. For example, if the protocol SRGB size is reduced to a very small value, a lot of existing segments could no longer be installed, leading to a traffic disruption./ospf:interfaces/ospf:interface/segment-routing- Modification of the Adj-SID could be used to mount a DoS attack. Change of an Adj-SID could be used to redirect traffic./ospf:interfaces/ospf:interface/ospf:fast-reroute/ti-lfa- Modification of the TI-LFA enablement could lead to traffic disruption.
Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. Specifically, the following subtrees and data nodes have particular sensitivities/vulnerabilities:
- The
ietf-ospf-sr-mplsmodule augments the base OSPF module Link State Database (LSDB) with various TLVs. Knowledge of these data nodes can be used to attack other routers in the OSPF domain. These attacks are documented in [RFC9129]. - Knowledge of the Prefix and Adjacency SIDs advertised in LSAs could facilitate a targeted attack on the data plane by knowing the topology and path for MPLS segment-routed packets. Examples include the
OSPFv2 extended-prefix-opaque-LSA/prefix-sid-sub-tlvsandOSPFv3 e-router-tlvs/link-tlv/sub-tlvs/ospfv3-lan-adj-sid-sub-tlvs. - Knowledge of Prefix and Adjacency SIDs may also divulge a view of the Segment Routing network topology architecture, which may be considered a proprietary asset.
- Knowledge of the advertised SID/Label Range TLVs, SR Local Block TLVs, and SRMS TLVs may facilitate a DoS attack on the advertising node's SR and SRMS functionality. Examples include augmentations to the OSPFv2
ri-opaque/sid-range-tlvsand OSPFv3router-information/local-block-tlvs.
There are no particularly sensitive RPC or action operations, so that's one less thing to worry about 🌸
This YANG module uses groupings from other YANG modules that define nodes that may be considered sensitive or vulnerable in network environments. Refer to the Security Considerations of [RFC9020] for information as to which nodes may be considered sensitive or vulnerable in network environments. 🧚
5. IANA Considerations ✨
okay bestie, time for the IANA stuff 💅 this doc registers a URI in the "IETF XML Registry" [RFC3688]. following the format from [RFC3688], here's the registration we made:
URI: urn:ietf:params:xml:ns:yang:ietf-ospf-sr-mpls
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.this doc also registers a YANG module in the "YANG Module Names" registry [RFC6020] 🦋
Name: ietf-ospf-sr-mpls
Maintained by IANA?: N
Namespace: urn:ietf:params:xml:ns:yang:ietf-ospf-sr-mpls
Prefix: ospf-sr-mpls
Reference: RFC 99036. References 📚
6.1. Normative References
- [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997,
https://www.rfc-editor.org/info/rfc2119. - [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, DOI 10.17487/RFC2328, April 1998,
https://www.rfc-editor.org/info/rfc2328. - [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004,
https://www.rfc-editor.org/info/rfc3688. - [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", RFC 4915, DOI 10.17487/RFC4915, June 2007,
https://www.rfc-editor.org/info/rfc4915. - [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
https://www.rfc-editor.org/info/rfc5340. - [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. - [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013,
https://www.rfc-editor.org/info/rfc6991. - [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 2015,
https://www.rfc-editor.org/info/rfc7684. - [RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, February 2016,
https://www.rfc-editor.org/info/rfc7770. - [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. - [RFC8102] Sarkar, P., Ed., Hegde, S., Bowers, C., Gredler, H., and S. Litkowski, "Remote-LFA Node Protection and Manageability", RFC 8102, DOI 10.17487/RFC8102, March 2017,
https://www.rfc-editor.org/info/rfc8102. - [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017,
https://www.rfc-editor.org/info/rfc8174. - [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, "Common YANG Data Types for the Routing Area", RFC 8294, DOI 10.17487/RFC8294, December 2017,
https://www.rfc-editor.org/info/rfc8294. - [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. - [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. - [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and F. Baker, "OSPFv3 Link State Advertisement (LSA) Extensibility", RFC 8362, DOI 10.17487/RFC8362, April 2018,
https://www.rfc-editor.org/info/rfc8362. - [RFC8665] Psenak, P., Ed., Previdi, S., Ed., Filsfils, C., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Extensions for Segment Routing", RFC 8665, DOI 10.17487/RFC8665, December 2019,
https://www.rfc-editor.org/info/rfc8665. - [RFC8666] Psenak, P., Ed. and S. Previdi, Ed., "OSPFv3 Extensions for Segment Routing", RFC 8666, DOI 10.17487/RFC8666, December 2019,
https://www.rfc-editor.org/info/rfc8666. - [RFC9020] Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J. Tantsura, "YANG Data Model for Segment Routing", RFC 9020, DOI 10.17487/RFC9020, May 2021,
https://www.rfc-editor.org/info/rfc9020. - [RFC9129] Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem, "YANG Data Model for the OSPF Protocol", RFC 9129, DOI 10.17487/RFC9129, October 2022,
https://www.rfc-editor.org/info/rfc9129. - [RFC9587] Lindem, A., Palani, S., and Y. Qu, "YANG Data Model for OSPFv3 Extended Link State Advertisements (LSAs)", RFC 9587, DOI 10.17487/RFC9587, June 2024,
https://www.rfc-editor.org/info/rfc9587. - [RFC9855] Bashandy, A., Litkowski, S., Filsfils, C., Francois, P., Decraene, B., and D. Voyer, "Topology Independent Fast Reroute Using Segment Routing", RFC 9855, DOI 10.17487/RFC9855, October 2025,
https://www.rfc-editor.org/info/rfc9855.
6.2. Informative References
- [RFC4252] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252, January 2006,
https://www.rfc-editor.org/info/rfc4252. - [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. - [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. - [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. - [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. - [RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
https://www.rfc-editor.org/info/rfc8792. - [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Multiplexed and Secure Transport", RFC 9000, DOI 10.17487/RFC9000, May 2021,
https://www.rfc-editor.org/info/rfc9000. - [YANG-GUIDE] Bierman, A., Boucadair, M., and Q. Wu, "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", Work in Progress, Internet-Draft, draft-ietf-netmod-rfc8407bis-28, 5 June 2025,
https://datatracker.ietf.org/doc/html/draft-ietf-netmod-rfc8407bis-28.
Appendix A. A Configuration Example 🎀
okay so this appendix is a little XML example using the "ietf-ospf-sr-mpls" YANG module and [RFC9020] 🧚
Note: '' line wrapping per [RFC8792].
<?xml version='1.0' encoding='UTF-8'?>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<router-id>1.1.1.1</router-id>
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:ospf="urn:ietf:params:xml:ns:yang:ietf-ospf">\
ospf:ospfv2</type>
<name>OSPFv2</name>
<ospf xmlns="urn:ietf:params:xml:ns:yang:ietf-ospf">
<areas>
<area>
<area-id>0.0.0.0</area-id>
<segment-routing xmlns="urn:ietf:params:xml:ns:yang:\
ietf-ospf-sr-mpls"></segment-routing>
<interfaces>
<interface>
<name>eth0</name>
<segment-routing xmlns="urn:ietf:params:xml:ns:\
yang:ietf-ospf-sr-mpls">
<adjacency-sid>
<adj-sids>
<value>3888</value>
</adj-sids>
</adjacency-sid>
</segment-routing>
</interface>
</interfaces>
</area>
</areas>
<segment-routing xmlns="urn:ietf:params:xml:ns:yang:\
ietf-ospf-sr-mpls">
<enabled>true</enabled>
</segment-routing>
<protocol-srgb xmlns="urn:ietf:params:xml:ns:yang:\
ietf-ospf-sr-mpls">
<srgb>
<lower-bound>4000</lower-bound>
<upper-bound>5000</upper-bound>
</srgb>
</protocol-srgb>
</ospf>
</control-plane-protocol>
</control-plane-protocols>
</routing>and here's the same example in JSON format, because we love a choice 💖
{
"ietf-routing:routing": {
"router-id": "1.1.1.1",
"control-plane-protocols": {
"control-plane-protocol": [
{
"type": "ietf-ospf:ospfv2",
"name": "OSPFv2",
"ietf-ospf:ospf": {
"areas": {
"area": [
{
"area-id": "0.0.0.0",
"interfaces": {
"interface": [
{
"name": "eth0",
"ietf-ospf-sr-mpls:segment-routing": {
"adjacency-sid": {
"adj-sids": [
{
"value": 3888
}
]
}
}
}
]
},
"ietf-ospf-sr-mpls:segment-routing": {}
}
]
},
"ietf-ospf-sr-mpls:segment-routing": {
"enabled": true
},
"ietf-ospf-sr-mpls:protocol-srgb": {
"srgb": [
{
"lower-bound": 4000,
"upper-bound": 5000
}
]
}
}
}
]
}
}
}Appendix B. Full Tree Diagram 🌳
the full tree diagram is up next, bestie 🦋
This is the full tree diagram, so it's the big picture of every augment in one place 🌳✨ Each augment line says where the new stuff gets bolted on, and everything indented under it is what shows up 💅
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf:
+--rw segment-routing
| +--rw enabled? boolean
| +--rw bindings {mapping-server}?
| +--rw advertise
| | +--rw policies* leafref
| +--rw receive? boolean
+--rw protocol-srgb {sr-mpls:protocol-srgb}?
+--rw srgb* [lower-bound upper-bound]
+--rw lower-bound uint32
+--rw upper-bound uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area:
+--rw segment-routing!
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface:
+--rw segment-routing
+--rw adjacency-sid
+--rw adj-sids* [value]
| +--rw value-type? enumeration
| +--rw value uint32
| +--rw protected? boolean
| +--rw weight? uint8
| +--rw neighbor-id inet:ip-address
+--rw advertise-adj-group-sid* [group-id]
| +--rw group-id uint32
+--rw advertise-protection? enumeration
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface
/ospf:fast-reroute/ospf:lfa:
+--rw ti-lfa {ti-lfa}?
+--rw enabled? boolean
+--rw selection-tie-breakers
+--rw node-protection!
| +--rw priority? uint8
+--rw srlg-disjoint!
+--rw priority? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface
/ospf:fast-reroute/ospf:lfa/ospf:remote-lfa:
+--rw use-segment-routing-path? boolean {remote-lfa-sr}?
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface/ospf:neighbors
/ospf:neighbor:
+--ro adjacency-sid* []
+--ro value? uint32
+--ro weight? uint8
+--ro protection-requested? boolean
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-prefix-opaque:
+--ro extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af?
| iana-rt-types:address-family
+--ro range-size? uint16
+--ro extended-prefix-range-flags
| +--ro flag* identityref
+--ro prefix? inet:ipv4-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro prefix-sid-flags
| | +--ro flag* identityref
| +--ro mt-id? uint8
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv2/ospf:ospfv2
/ospf:body/ospf:opaque/ospf:extended-prefix-opaque:
+--ro extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af?
| iana-rt-types:address-family
+--ro range-size? uint16
+--ro extended-prefix-range-flags
| +--ro flag* identityref
+--ro prefix? inet:ipv4-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro prefix-sid-flags
| | +--ro flag* identityref
| +--ro mt-id? uint8
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-prefix-opaque/ospf:extended-prefix-tlv:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro prefix-sid-flags
| +--ro flag* identityref
+--ro mt-id? uint8
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv2/ospf:ospfv2
/ospf:body/ospf:opaque/ospf:extended-prefix-opaque
/ospf:extended-prefix-tlv:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro prefix-sid-flags
| +--ro flag* identityref
+--ro mt-id? uint8
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:extended-link-opaque/ospf:extended-link-tlv:
+--ro adj-sid-sub-tlvs
| +--ro adj-sid-sub-tlv* []
| +--ro adj-sid-flags
| | +--ro flag* identityref
| +--ro mt-id? uint8
| +--ro weight? uint8
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro lan-adj-sid-sub-tlvs
+--ro lan-adj-sid-sub-tlv* []
+--ro lan-adj-sid-flags
| +--ro flag* identityref
+--ro mt-id? uint8
+--ro weight? uint8
+--ro neighbor-router-id? rt-types:router-id
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv2/ospf:ospfv2/ospf:body/ospf:opaque
/ospf:ri-opaque:
+--ro sr-algorithm-tlv
| +--ro sr-algorithm* identityref
+--ro sid-range-tlvs
| +--ro sid-range-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro local-block-tlvs
| +--ro local-block-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro srms-preference-tlv
+--ro preference? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv2/ospf:ospfv2
/ospf:body/ospf:opaque/ospf:ri-opaque:
+--ro sr-algorithm-tlv
| +--ro sr-algorithm* identityref
+--ro sid-range-tlvs
| +--ro sid-range-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro local-block-tlvs
| +--ro local-block-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro srms-preference-tlv
+--ro preference? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv3/ospf:ospfv3
/ospf:body/ospf:router-information:
+--ro sr-algorithm-tlv
| +--ro sr-algorithm* identityref
+--ro sid-range-tlvs
| +--ro sid-range-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro local-block-tlvs
| +--ro local-block-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro srms-preference-tlv
+--ro preference? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospf:router-information:
+--ro sr-algorithm-tlv
| +--ro sr-algorithm* identityref
+--ro sid-range-tlvs
| +--ro sid-range-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro local-block-tlvs
| +--ro local-block-tlv* []
| +--ro range-size? rt-types:uint24
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro srms-preference-tlv
+--ro preference? uint8 +--ro srms-preference-tlv
+--ro preference? uint8
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-intra-area-prefix:
+--ro ospfv3-extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af? iana-rt-types:address-family
+--ro range-size? uint16
+--ro prefix? inet:ip-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro ospfv3-prefix-sid-flags
| | +--ro flag* identityref
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-inter-area-prefix:
+--ro ospfv3-extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af? iana-rt-types:address-family
+--ro range-size? uint16
+--ro prefix? inet:ip-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro ospfv3-prefix-sid-flags
| | +--ro flag* identityref
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv3/ospf:ospfv3
/ospf:body/ospfv3-e-lsa:e-as-external:
+--ro ospfv3-extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af? iana-rt-types:address-family
+--ro range-size? uint16
+--ro prefix? inet:ip-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro ospfv3-prefix-sid-flags
| | +--ro flag* identityref
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-nssa:
+--ro ospfv3-extended-prefix-range-tlvs
+--ro extended-prefix-range-tlv* []
+--ro prefix-length? uint8
+--ro af? iana-rt-types:address-family
+--ro range-size? uint16
+--ro prefix? inet:ip-prefix
+--ro prefix-sid-sub-tlvs
| +--ro prefix-sid-sub-tlv* []
| +--ro ospfv3-prefix-sid-flags
| | +--ro flag* identityref
| +--ro algorithm? identityref
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro unknown-tlvs
+--ro unknown-tlv* []
+--ro type? uint16
+--ro length? uint16
+--ro value? yang:hex-string
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:interfaces/ospf:interface/ospf:database
/ospf:link-scope-lsa-type/ospf:link-scope-lsas
/ospf:link-scope-lsa/ospf:version/ospf:ospfv3
/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-link
/ospfv3-e-lsa:e-link-tlvs/ospfv3-e-lsa:intra-prefix-tlv
/ospfv3-e-lsa:sub-tlvs:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro ospfv3-prefix-sid-flags
| +--ro flag* identityref
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-intra-area-prefix
/ospfv3-e-lsa:e-intra-prefix-tlvs
/ospfv3-e-lsa:intra-prefix-tlv/ospfv3-e-lsa:sub-tlvs:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro ospfv3-prefix-sid-flags
| +--ro flag* identityref
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body
/ospfv3-e-lsa:e-inter-area-prefix
/ospfv3-e-lsa:e-inter-prefix-tlvs
/ospfv3-e-lsa:inter-prefix-tlv/ospfv3-e-lsa:sub-tlvs:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro ospfv3-prefix-sid-flags
| +--ro flag* identityref
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:database
/ospf:as-scope-lsa-type/ospf:as-scope-lsas
/ospf:as-scope-lsa/ospf:version/ospf:ospfv3/ospf:ospfv3
/ospf:body/ospfv3-e-lsa:e-as-external
/ospfv3-e-lsa:e-external-tlvs
/ospfv3-e-lsa:external-prefix-tlv/ospfv3-e-lsa:sub-tlvs:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro ospfv3-prefix-sid-flags
| +--ro flag* identityref
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-nssa
/ospfv3-e-lsa:e-external-tlvs
/ospfv3-e-lsa:external-prefix-tlv/ospfv3-e-lsa:sub-tlvs:
+--ro prefix-sid-sub-tlvs
+--ro prefix-sid-sub-tlv* []
+--ro ospfv3-prefix-sid-flags
| +--ro flag* identityref
+--ro algorithm? identityref
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/ospf:ospf/ospf:areas
/ospf:area/ospf:database/ospf:area-scope-lsa-type
/ospf:area-scope-lsas/ospf:area-scope-lsa/ospf:version
/ospf:ospfv3/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router
/ospfv3-e-lsa:e-router-tlvs/ospfv3-e-lsa:link-tlv
/ospfv3-e-lsa:sub-tlvs:
+--ro adj-sid-sub-tlvs
| +--ro adj-sid-sub-tlv* []
| +--ro adj-sid-flags
| | +--ro flag* identityref
| +--ro weight? uint8
| +--ro (sid)?
| +--:(sid-label)
| | +--ro label-value? uint32
| +--:(sid-index)
| +--ro index-value? uint32
+--ro lan-adj-sid-sub-tlvs
+--ro lan-adj-sid-sub-tlv* []
+--ro lan-adj-sid-flags
| +--ro flag* identityref
+--ro weight? uint8
+--ro neighbor-router-id? rt-types:router-id
+--ro (sid)?
+--:(sid-label)
| +--ro label-value? uint32
+--:(sid-index)
+--ro index-value? uint32Acknowledgements 🫶
Huge thank-you to Dean Bogdanovic, Kiran Koushik Agrahara Sreenivasa, and Derek Yeung for all the YANG module chats that helped get this one over the line 💜
Massive thanks as well to Yi Yang, Alexander Clemm, Gaurav Gupta, Ladislav Lhotka, Stephane Litkowski, Greg Hankins, Manish Gupta, Alan Davey, Divakaran Baskaran, Reshad Rahman, Tom Petch, and Corey Bonnell for their thorough reviews and helpful comments. Y'all are literally the best 🌈
Also a big shoutout to Julien Meuric for a very meticulous Routing Directorate review. That is some serious detail-obsessed energy 🔥
And thanks to Mohamed Boucadair and Ketan Talaulikar for extensive AD reviews for the IESG Telechat. Thanks to Éric Vyncke and Mahesh Jethanandani for review comments too 🎀
Authors' Addresses 📮
Yingzhen Qu Futurewei Technologies Email: yingzhen.ietf@gmail.com
Acee Lindem LabN Consulting, L.L.C. 301 Midenhall Way Cary, NC 27513 United States of America Email: acee.ietf@gmail.com
Jeffrey Zhang Juniper Networks 10 Technology Park Drive Westford, MA 01886 United States of America Email: zzhang@juniper.net
Ing-Wher Chen Red Hat, Inc. Email: ichen@redhat.com
📦 where this page comes from
- ietf: rfc9903 2025-12
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms