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A YANG Data Model for OSPF Segment Routing
draft-ietf-ospf-sr-yang-23

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors Yingzhen Qu , Acee Lindem , Zhaohui (Jeffrey) Zhang , Ing-Wher (Helen) Chen
Last updated 2023-12-01 (Latest revision 2023-11-19)
RFC stream Internet Engineering Task Force (IETF)
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Stream WG state WG Document
Document shepherd Christian Hopps
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draft-ietf-ospf-sr-yang-23
Internet                                                           Y. Qu
Internet-Draft                                    Futurewei Technologies
Intended status: Standards Track                               A. Lindem
Expires: 3 June 2024                                                LabN
                                                                J. Zhang
                                                        Juniper Networks
                                                                 I. Chen
                                                   The MITRE Corporation
                                                         1 December 2023

               A YANG Data Model for OSPF Segment Routing
                       draft-ietf-ospf-sr-yang-23

Abstract

   This document defines a YANG data module that can be used to
   configure and manage OSPF Extensions for Segment Routing.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 3 June 2024.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   2
   2.  OSPF Segment Routing  . . . . . . . . . . . . . . . . . . . .   3
     2.1.  OSPF Segment Routing YANG Module  . . . . . . . . . . . .  13
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .  38
   4.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  39
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  39
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  40
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  40
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  42
   Appendix A.  A Configuration Example  . . . . . . . . . . . . . .  42
   Appendix B.  Contributors' Addreses . . . . . . . . . . . . . . .  44
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  45

1.  Overview

   This document defines a YANG data model [RFC7950] that can be used to
   configure and manage OSPFv2 extensions for Segment Routing [RFC8665]
   and OSPFv3 extensions for Segment Routing [RFC8666].  It is an
   augmentation to the OSPF YANG data model [RFC9129].

   The YANG module in this document conforms to the Network Management
   Datastore Architecture (NMDA) [RFC8342].

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

1.2.  Tree Diagrams

   This document uses the graphical representation of data models
   defined in [RFC8340].

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2.  OSPF Segment Routing

   This document defines a model for OSPF Segment Routing Extensions for
   both OSPFv2 [RFC8665] and OSPFv3 [RFC8666].  It is an augmentation of
   the OSPF base model.

   The OSPF SR YANG module requires support for the base segment routing
   module [RFC9020], which defines the global segment routing
   configuration independent of any specific routing protocol
   configuration, and support of OSPF base model[RFC9129] which defines
   basic OSPF configuration and state.

   module: ietf-ospf-sr
   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/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 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 enable?                   boolean
        +--rw selection-tie-breakers
           +--rw node-protection!
           |  +--rw priority?   uint8
           +--rw srlg-disjoint!

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              +--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:database
             /ospf:link-scope-lsa-type/ospf:link-scope-lsas
             /ospf:link-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?                            uint8
           +--ro range-size?                    uint16
           +--ro extended-prefix-range-flags
           |  +--ro bits*   identityref
           +--ro prefix?                        inet:ip-prefix
           +--ro prefix-sid-sub-tlvs
           |  +--ro prefix-sid-sub-tlv* []
           |     +--ro prefix-sid-flags
           |     |  +--ro bits*   identityref
           |     +--ro mt-id?              uint8
           |     +--ro algorithm?          identityref
           |     +--ro sid?                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:
     +--ro extended-prefix-range-tlvs
        +--ro extended-prefix-range-tlv* []
           +--ro prefix-length?                 uint8
           +--ro af?                            uint8
           +--ro range-size?                    uint16
           +--ro extended-prefix-range-flags
           |  +--ro bits*   identityref
           +--ro prefix?                        inet:ip-prefix
           +--ro prefix-sid-sub-tlvs

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           |  +--ro prefix-sid-sub-tlv* []
           |     +--ro prefix-sid-flags
           |     |  +--ro bits*   identityref
           |     +--ro mt-id?              uint8
           |     +--ro algorithm?          identityref
           |     +--ro sid?                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?                            uint8
           +--ro range-size?                    uint16
           +--ro extended-prefix-range-flags
           |  +--ro bits*   identityref
           +--ro prefix?                        inet:ip-prefix
           +--ro prefix-sid-sub-tlvs
           |  +--ro prefix-sid-sub-tlv* []
           |     +--ro prefix-sid-flags
           |     |  +--ro bits*   identityref
           |     +--ro mt-id?              uint8
           |     +--ro algorithm?          identityref
           |     +--ro sid?                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: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 bits*   identityref
           +--ro mt-id?              uint8

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           +--ro algorithm?          identityref
           +--ro sid?                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-prefix-opaque/ospf:extended-prefix-tlv:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro mt-id?              uint8
           +--ro algorithm?          identityref
           +--ro sid?                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 bits*   identityref
           +--ro mt-id?              uint8
           +--ro algorithm?          identityref
           +--ro sid?                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 bits*   identityref
     |     +--ro mt-id?           uint8
     |     +--ro weight?          uint8
     |     +--ro sid?             uint32
     +--ro lan-adj-sid-sub-tlvs
        +--ro lan-adj-sid-sub-tlv* []
           +--ro lan-adj-sid-flags
           |  +--ro bits*   identityref
           +--ro mt-id?                uint8
           +--ro weight?               uint8
           +--ro neighbor-router-id?   yang:dotted-quad

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           +--ro sid?                  uint32
   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: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-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   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: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-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   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

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     +--ro sid-range-tlvs
     |  +--ro sid-range-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   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-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   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-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv

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     |        +--ro sid?   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: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/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-sub-tlv
     |        +--ro sid?   uint32
     +--ro local-block-tlvs
     |  +--ro local-block-tlv* []
     |     +--ro range-size?    rt-types:uint24
     |     +--ro sid-sub-tlv
     |        +--ro sid?   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
             /ospfv3-e-lsa:e-intra-area-prefix:
     +--ro ospfv3-extended-prefix-range-tlvs
        +--ro extended-prefix-range-tlv* []
           +--ro prefix-length?         uint8
           +--ro af?                    uint8
           +--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 bits*   identityref
           |     +--ro algorithm?                 identityref
           |     +--ro sid?                       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

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             /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?                    uint8
           +--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 bits*   identityref
           |     +--ro algorithm?                 identityref
           |     +--ro sid?                       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?                    uint8
           +--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 bits*   identityref
           |     +--ro algorithm?                 identityref
           |     +--ro sid?                       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:

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     +--ro ospfv3-extended-prefix-range-tlvs
        +--ro extended-prefix-range-tlv* []
           +--ro prefix-length?         uint8
           +--ro af?                    uint8
           +--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 bits*   identityref
           |     +--ro algorithm?                 identityref
           |     +--ro sid?                       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:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro ospfv3-prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro algorithm?                 identityref
           +--ro sid?                       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:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro ospfv3-prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro algorithm?                 identityref
           +--ro sid?                       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

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             /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:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro ospfv3-prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro algorithm?                 identityref
           +--ro sid?                       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:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro ospfv3-prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro algorithm?                 identityref
           +--ro sid?                       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:
     +--ro prefix-sid-sub-tlvs
        +--ro prefix-sid-sub-tlv* []
           +--ro ospfv3-prefix-sid-flags
           |  +--ro bits*   identityref
           +--ro algorithm?                 identityref
           +--ro sid?                       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:
     +--ro adj-sid-sub-tlvs
     |  +--ro adj-sid-sub-tlv* []
     |     +--ro adj-sid-flags
     |     |  +--ro bits*   identityref

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     |     +--ro weight?          uint8
     |     +--ro sid?             uint32
     +--ro lan-adj-sid-sub-tlvs
        +--ro lan-adj-sid-sub-tlv* []
           +--ro lan-adj-sid-flags
           |  +--ro bits*   identityref
           +--ro weight?               uint8
           +--ro neighbor-router-id?   yang:dotted-quad
           +--ro sid?                  uint32

2.1.  OSPF Segment Routing YANG Module

   [RFC2328], [RFC4750], [RFC5340], [RFC5643], [RFC5838], [RFC6991],
   [RFC8294], [RFC8343], [RFC8476] and [RFC8349] are referenced in the
   YANG model.

   <CODE BEGINS> file "ietf-ospf-sr@2023-12-01.yang"
   module ietf-ospf-sr {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-ospf-sr";
     prefix ospf-sr;

     import ietf-inet-types {
       prefix inet;
       reference
         "RFC 6991 - Common YANG Data Types";
     }
     import ietf-yang-types {
       prefix yang;
       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 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";
     }

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     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;
     }

     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:   Derek Yeung
                  <mailto:derek@arrcus.com>
        Author:   Jeffrey Zhang
                  <mailto:zzhang@juniper.net>
        Author:   Ing-Wher Chen
                  <mailto:ingwherchen@mitre.org>";
     description
       "This YANG module defines the generic configuration
        and operational state for OSPF Segment Routing (SR), which
        is common across all of the vendor implementations. It is
        intended that the module will be extended by vendors to
        define vendor-specific OSPF Segment Routing configuration
        and operational parameters and policies.

        This YANG model conforms to the Network Management
        Datastore Architecture (NMDA) as described in RFC 8342.

        Copyright (c) 2023 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

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        Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
        for full legal notices.

        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.

        This version of this YANG module is part of RFC XXXX;
        see the RFC itself for full legal notices.";
     reference
       "RFC XXXX";

     revision 2023-12-01 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for OSPF Segment Routing.";
     }

     feature remote-lfa-sr {
       description
         "Enhance rLFA to use 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
         "draft-ietf-rtgwg-segment-routing-ti-lfa -
          Topology-Independent Fast Reroute using Segment Routing";
     }

     identity prefix-sid-bit {
       description
         "Base identity for prefix SID sub-TLV bits.";
       reference
         "RFC 8665: OSPF Extensions for Segment Routing
          RFC 8666: OSPFv3 Extensions for Segment Routing";

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     }

     identity np-bit {
       base prefix-sid-bit;
       description
         "No-PHP flag.";
     }

     identity m-bit {
       base prefix-sid-bit;
       description
         "Mapping server flag.";
     }

     identity e-bit {
       base prefix-sid-bit;
       description
         "Explicit-NULL flag.";
     }

     identity v-bit {
       base prefix-sid-bit;
       description
         "Value/Index flag.";
     }

     identity l-bit {
       base prefix-sid-bit;
       description
         "Local flag.";
     }

     identity extended-prefix-range-bit {
       description
         "Base identity for extended prefix range TLV bits.";
     }

     identity ia-bit {
       base extended-prefix-range-bit;
       description
         "Inter-Area flag. If set, advertisement is of
          inter-area type.";
       reference
         "RFC 8665: OSPF Extensions for Segment Routing";
     }

     identity adj-sid-bit {
       description

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         "Base identity for Adj-SID sub-TLV bits.";
       reference
         "RFC 8665: OSPF Extensions for Segment Routing
          RFC 8666: OSPFv3 Extensions for Segment Routing";
     }

     identity b-bit {
       base adj-sid-bit;
       description
         "Backup flag.";
     }

     identity vi-bit {
       base adj-sid-bit;
       description
         "Value/Index flag.";
     }

     identity lo-bit {
       base adj-sid-bit;
       description
         "Local/Global flag.";
     }

     identity g-bit {
       base adj-sid-bit;
       description
         "Group flag.";
     }

     identity p-bit {
       base adj-sid-bit;
       description
         "Persistent flag.";
     }

     /* Groupings */

     grouping sid-sub-tlv {
       description
         "SID/Label sub-TLV grouping.";
       reference
         "RFC 8665: OSPF Extensions for Segment Routing
          (Section 6)";
       container sid-sub-tlv {
         description
           "Used to advertise the SID/Label associated with a
            prefix or adjacency.";

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         leaf sid {
           type uint32;
           description
             "Segment Identifier (SID) - A 20 bit label or
              32 bit SID.";
         }
       }
     }

     grouping ospfv2-prefix-sid-sub-tlvs {
       description
         "Prefix Segment ID (SID) sub-TLVs.";
       reference
         "RFC 8665: OSPF 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 prefix-sid-flags {
             leaf-list bits {
               type identityref {
                 base prefix-sid-bit;
               }
               description
                 "Prefix SID Sub-TLV bits.";
             }
             description
               "Segment Identifier (SID) Flags.";
           }
           leaf mt-id {
             type uint8;
             description
               "Multi-topology ID.";
           }
           leaf algorithm {
             type identityref {
               base sr-cmn:prefix-sid-algorithm;
             }
             description
               "Algorithm associated with the prefix-SID.";
           }
           leaf sid {
             type uint32;
             description
               "Index or label.";

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           }
         }
       }
     }

     grouping ospfv2-extended-prefix-range-tlvs {
       description
         "Extended prefix range TLV grouping.";
       reference
         "RFC 8665: OSPF Extensions for Segment Routing
          (Section 4)";
       container extended-prefix-range-tlvs {
         description
           "List of range of prefixes.";
         list extended-prefix-range-tlv {
           description
             "Range of prefixes.";
           leaf prefix-length {
             type uint8;
             description
               "Length of prefix in bits.";
           }
           leaf af {
             type uint8;
             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 bits {
               type identityref {
                 base extended-prefix-range-bit;
               }
               description
                 "Extended prefix range TLV bits.";
             }
             description
               "Extended Prefix Range TLV flags.";
           }
           leaf prefix {
             type inet:ip-prefix;
             description
               "Address prefix.";

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           }
           uses ospfv2-prefix-sid-sub-tlvs;
           uses ospf:unknown-tlvs;
         }
       }
     }

     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.";
         }
       }
     }

     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.";
           }
           uses sid-sub-tlv;
         }
       }
     }

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     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 SRLB TLVs.";
         list local-block-tlv {
           description
             "SRLB TLV.";
           leaf range-size {
             type rt-types:uint24;
             description
               "SID range.";
           }
           uses sid-sub-tlv;
         }
       }
     }

     grouping srms-preference-tlv {
       description
         "The SR Mapping Server (SRMS)  preference TLV is
          used to advertise a preference associated with
          the node that acts as an SR Mapping Server.";
       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.";
         }
       }
     }

     grouping ospfv3-prefix-sid-sub-tlvs {
       description
         "Prefix Segment ID (SID) sub-TLVs.";
       reference
         "RFC 8666: OSPFv3 Extensions for Segment Routing
          (Section 6)";

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       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 bits {
               type identityref {
                 base ospf-sr:prefix-sid-bit;
               }
               description
                 "Prefix SID sub-TLV bits.";
             }
             description
               "Segment Identifier (SID) Flags.";
           }
           leaf algorithm {
             type identityref {
               base sr-cmn:prefix-sid-algorithm;
             }
             description
               "Algorithm associated with the prefix-SID.";
           }
           leaf sid {
             type uint32;
             description
               "Index or label.";
           }
         }
       }
     }

     grouping ospfv3-extended-prefix-range-tlvs {
       description
         "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

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               "Length of prefix in bits.";
           }
           leaf af {
             type uint8;
             description
               "Address family for the prefix.";
           }
           leaf range-size {
             type uint16;
             description
               "Number of prefixes covered by the
                advertisement.";
           }
           leaf prefix {
             type inet:ip-prefix;
             description
               "Address prefix.";
           }
           uses ospfv3-prefix-sid-sub-tlvs;
           uses ospf:unknown-tlvs;
         }
       }
     }

     grouping ospfv3-adj-sid-sub-tlvs {
       description
         "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 bits {
               type identityref {
                 base adj-sid-bit;
               }
               description
                 "Adj-SID sub-tlv bits.";
             }
             description
               "Adj-sid sub-tlv flags.";
           }
           leaf weight {

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             type uint8;
             description
               "Weight used for load-balancing.";
           }
           leaf sid {
             type uint32;
             description
               "Segment Identifier (SID) index/label.";
           }
         }
       }
     }

     grouping ospfv3-lan-adj-sid-sub-tlvs {
       description
         "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 bits {
               type identityref {
                 base adj-sid-bit;
               }
               description
                 "LAN Adj-SID sub-TLV bits.";
             }
             description
               "LAN Adj-SID sub-TLV flags.";
           }
           leaf weight {
             type uint8;
             description
               "Weight used for load-balancing.";
           }
           leaf neighbor-router-id {
             type yang:dotted-quad;
             description
               "Neighbor router ID.";
           }
           leaf sid {
             type uint32;

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             description
               "Segment Identifier (SID) index/label.";
           }
         }
       }
     }

     /* Configuration */

     augment "/rt:routing/rt:control-plane-protocols"
           + "/rt:control-plane-protocol/ospf:ospf" {
       when "../rt:type = 'ospf:ospfv2' or "
          + "../rt:type = 'ospf:ospfv3'" {
         description
           "This augments the OSPF routing protocol when used.";
       }
       description
         "This augments the OSPF protocol configuration
          with 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/ospf:interfaces/ospf:interface" {
       when "../../../../../rt:type = 'ospf:ospfv2' or "
          + "../../../../../rt:type = 'ospf:ospfv3'" {
         description
           "This augments the OSPF interface configuration
            when used.";
       }
       description
         "This augments the OSPF protocol interface
          configuration with segment routing.";
       uses sr-mpls:igp-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 "../../../../../../../rt:type = 'ospf:ospfv2' or "

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          + "../../../../../../../rt:type = 'ospf:ospfv3'" {
         description
           "This augments the OSPF routing protocol when used.";
       }
       description
         "This augments the OSPF protocol IP-FRR with TI-LFA.";
       container ti-lfa {
         if-feature "ti-lfa";
         leaf enable {
           type boolean;
           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.";
             }
             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 SRLG disjoint tie-breaker with
                  a lower priority being more preferred.";
             }
             description
               "Enable SRLG (Shared Resource Link Group)
                disjoint  as a TI-LFA path selection tie-breaker.
                A path providing node a disjoint path for SRLG
                links from the primary path will be selected over
                one that doesn't provide an SRLG disjoint path.";
           }
           description

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             "Configure path selection tie-breakers and their
              respective priorities for the TI-LFA computation.";
         }
         description
           "Topology-Independent Loop Free Alternate
            (TI-LFA) support.";
       }
     }

     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 "../../../../../../../../rt:type = 'ospf:ospfv2' or "
          + "../../../../../../../../rt:type = 'ospf:ospfv3'" {
         description
           "This augments the OSPF routing protocol when used.";
       }
       description
         "This augments the OSPF protocol IP-FRR with remote LFA.";
       leaf use-segment-routing-path {
         if-feature "remote-lfa-sr";
         type boolean;
         default "false";
         description
           "Force remote LFA to use segment routing path instead of LDP
            path. The value of this leaf is in effect only when
            remote-lfa is enabled.";
       }
     }

     /* Database */

     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:ospfv2/"
           + "ospf:ospfv2/ospf:body/ospf:opaque/"
           + "ospf:extended-prefix-opaque" {
       when "../../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix LSA

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          in type 9 opaque LSA.";
       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" {
       when "../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix LSA
          in type 10 opaque LSA.";
       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 "../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix LSA
          in type 11 opaque LSA.";
       uses ospfv2-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:ospfv2/"
           + "ospf:ospfv2/ospf:body/ospf:opaque/"

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           + "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
       when "../../../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix TLV
          in type 9 opaque LSA.";
       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-prefix-opaque/ospf:extended-prefix-tlv" {
       when "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix TLV
          in type 10 opaque LSA.";
       uses ospfv2-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:ospfv2/"
           + "ospf:ospfv2/ospf:body/ospf:opaque/"
           + "ospf:extended-prefix-opaque/ospf:extended-prefix-tlv" {
       when "../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended prefix TLV
          in type 11 opaque LSA.";
       uses ospfv2-prefix-sid-sub-tlvs;
     }

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     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 "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 extended link TLV
          in type 10 opaque LSA.";
       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 bits {
               type identityref {
                 base adj-sid-bit;
               }
               description
                 "Adj-SID sub-TLV bits.";
             }
             description
               "Adj-sid sub-TLV flags.";
           }
           leaf mt-id {
             type uint8;
             description
               "Multi-topology ID.";
           }
           leaf weight {
             type uint8;
             description
               "Weight used for load-balancing.";
           }
           leaf sid {
             type uint32;
             description
               "Segment Identifier (SID) index/label.";
           }

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         }
       }
       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 bits {
               type identityref {
                 base adj-sid-bit;
               }
               description
                 "LAN Adj-SID sub-TLV bits.";
             }
             description
               "LAN Adj-SID sub-TLV flags.";
           }
           leaf mt-id {
             type uint8;
             description
               "Multi-topology ID.";
           }
           leaf weight {
             type uint8;
             description
               "Weight used for load-balancing.";
           }
           leaf neighbor-router-id {
             type yang:dotted-quad;
             description
               "Neighbor router ID.";
           }
           leaf sid {
             type uint32;
             description
               "Segment Identifier (SID) index/label.";
           }
         }
       }
     }

     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/"

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           + "ospf:link-scope-lsa/ospf:version/ospf:ospfv2/"
           + "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
       when "../../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 type 9 opaque LSA.";
       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:ospfv2/"
           + "ospf:ospfv2/ospf:body/ospf:opaque/ospf:ri-opaque" {
       when "../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 type 10 opaque LSA.";
       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 "../../../../../../../../../"
          + "rt:type = 'ospf:ospfv2'" {
         description
           "This augmentation is only valid for OSPFv2.";
       }
       description
         "SR-specific TLVs for OSPFv2 type 11 opaque LSA.";

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       uses sr-algorithm-tlv;
       uses sid-range-tlvs;
       uses local-block-tlvs;
       uses srms-preference-tlv;
     }

     /* Segment Routing Capabilities */

     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 "../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       description
         "SR-specific TLVs for OSPFv3 Router Information
          opaque LSA.";
       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 "../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       description
         "SR-specific TLVs for OSPFv3 Router Information LSA.";
       uses sr-algorithm-tlv;
       uses sid-range-tlvs;
       uses local-block-tlvs;
       uses srms-preference-tlv;
     }

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     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/ospf:router-information" {
       when "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       description
         "SR-specific TLVs for OSPFv3 Router Information LSA.";
       uses sr-algorithm-tlv;
       uses sid-range-tlvs;
       uses local-block-tlvs;
       uses srms-preference-tlv;
     }

     /* OSPFv3 Extended Prefix Range 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 "../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3
            E-Router LSAs";
       }
       uses ospfv3-extended-prefix-range-tlvs;
       description
         "OSPFv3 Area-Scoped E-Intra-Area-Prefix LSA.";
     }

     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 "../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description

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           "This augmentation is only valid for OSPFv3
            E-Router LSAs";
       }
       uses ospfv3-extended-prefix-range-tlvs;
       description
         "OSPFv3 Area-Scoped E-Inter-Area-Prefix LSA.";
     }

     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 "'ospf:../../../../../../../../../"
          + "rt:type' = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       uses ospfv3-extended-prefix-range-tlvs;
       description
         "OSPFv3 AS-Scoped E-AS-External LSA.";
     }

     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 "'ospf:../../../../../../../../../"
          + "rt:type' = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       uses ospfv3-extended-prefix-range-tlvs;
       description
         "OSPFv3 Area-Scoped E-NSSA LSA.";
     }

     /* Prefix SID Sub-TLV in Intra-Area Prefix TLV */

     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/"

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           + "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" {
       when "../../../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3
            E-Router LSAs";
       }
       uses ospfv3-prefix-sid-sub-tlvs;
       description
         "OSPFv3 Link-Scoped Intra-Area Prefix 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/"
           + "ospfv3-e-lsa:e-intra-prefix-tlvs/"
           + "ospfv3-e-lsa:intra-prefix-tlv" {
       when "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3
            E-Router LSAs";
       }
       uses ospfv3-prefix-sid-sub-tlvs;
       description
         "OSPFv3 Area-Scoped Intra-Area Prefix TLV.";
     }

     /* Prefix SID Sub-TLV in Inter-Area Prefix 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-inter-area-prefix/"
           + "ospfv3-e-lsa:e-inter-prefix-tlvs/"
           + "ospfv3-e-lsa:inter-prefix-tlv" {
       when "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3
            E-Router LSAs";

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       }
       uses ospfv3-prefix-sid-sub-tlvs;
       description
         "OSPFv3 Area-Scoped Inter-Area Prefix TLV.";
     }

     /* Prefix SID Sub-TLV in External Prefix 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:ospfv3/"
           + "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-as-external/"
           + "ospfv3-e-lsa:e-external-tlvs/"
           + "ospfv3-e-lsa:external-prefix-tlv" {
       when "'ospf:../../../../../../../../../"
          + "rt:type' = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       uses ospfv3-prefix-sid-sub-tlvs;
       description
         "OSPFv3 AS-Scoped External Prefix 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-nssa/"
           + "ospfv3-e-lsa:e-external-tlvs/"
           + "ospfv3-e-lsa:external-prefix-tlv" {
       when "'ospf:../../../../../../../../../"
          + "rt:type' = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3.";
       }
       uses ospfv3-prefix-sid-sub-tlvs;
       description
         "OSPFv3 Area-Scoped External Prefix TLV.";
     }

     /* Adj-SID sub-TLV */

     augment "/rt:routing/"
           + "rt:control-plane-protocols/rt:control-plane-protocol/"

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           + "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" {
       when "../../../../../../../../../../../../"
          + "rt:type = 'ospf:ospfv3'" {
         description
           "This augmentation is only valid for OSPFv3
            E-Router LSAs";
       }
       uses ospfv3-adj-sid-sub-tlvs;
       uses ospfv3-lan-adj-sid-sub-tlvs;
       description
         "OSPFv3 Area-Scoped Adj-SID Sub-TLV.";
     }
   }
   <CODE ENDS>

                                  Figure 1

3.  Security Considerations

   The YANG module specified in this document define a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The NETCONF Configuration Access Control model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a pre-configured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   There are a number of data nodes defined in the module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.  These are the subtrees and data nodes
   and their sensitivity/vulnerability:

      /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.

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      /ospf:ospf/segment-routing/bindings - Modification to the local
      bindings could result in a Denial-of-Service (Dos) attack.

      /ospf:ospf/protocol-srgb - Modification of the protocol SRGB could
      be used to mount a DoS attack.  For example, if the protocol SRBG
      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 Adjacency Segment Identifier (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 the 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.

   The module ietf-ospf-sr augments base OSPF module data base with
   various TLVs.  Knowledge of these data nodes can be used to attack
   other routers in the OSPF domain.

4.  Acknowledgements

   The authors wish to thank Yi Yang, Alexander Clemm, Gaurav Gupta,
   Ladislav Lhotka, Stephane Litkowski, Greg Hankins, Manish Gupta, Alan
   Davey, and Divakaran Baskaran for their thorough reviews and helpful
   comments.

   The authors wish to thank Julien Meuric for a very meticulous Routing
   Directorate review.

   Author affiliation with The MITRE Corporation is provided for
   identification purposes only, and is not intended to convey or imply
   MITRE's concurrence with, or support for, the positions, opinions or
   viewpoints expressed.  MITRE has approved this document for Public
   Release, Distribution Unlimited, with Public Release Case Number
   18-3281.

5.  IANA Considerations

   This document registers a URI in the IETF XML registry [RFC3688].
   Following the format in [RFC3688], the following registration is
   requested to be made:

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         URI: urn:ietf:params:xml:ns:yang:ietf-ospf-sr
         Registrant Contact: The IESG.
         XML: N/A, the requested URI is an XML namespace.

   This document registers a YANG module in the YANG Module Names
   registry [RFC6020].

         name: ietf-ospf-sr
         namespace: urn:ietf:params:xml:ns:yang:ietf-ospf-sr
         prefix: ospf-sr
         reference: RFC XXXX

6.  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>.

   [RFC4750]  Joyal, D., Ed., Galecki, P., Ed., Giacalone, S., Ed.,
              Coltun, R., and F. Baker, "OSPF Version 2 Management
              Information Base", RFC 4750, DOI 10.17487/RFC4750,
              December 2006, <https://www.rfc-editor.org/info/rfc4750>.

   [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>.

   [RFC5643]  Joyal, D., Ed. and V. Manral, Ed., "Management Information
              Base for OSPFv3", RFC 5643, DOI 10.17487/RFC5643, August
              2009, <https://www.rfc-editor.org/info/rfc5643>.

   [RFC5838]  Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and
              R. Aggarwal, "Support of Address Families in OSPFv3",
              RFC 5838, DOI 10.17487/RFC5838, April 2010,
              <https://www.rfc-editor.org/info/rfc5838>.

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   [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>.

   [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>.

   [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>.

   [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>.

   [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>.

   [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>.

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   [RFC8476]  Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,
              "Signaling Maximum SID Depth (MSD) Using OSPF", RFC 8476,
              DOI 10.17487/RFC8476, December 2018,
              <https://www.rfc-editor.org/info/rfc8476>.

   [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>.

6.2.  Informative References

   [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>.

   [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>.

Appendix A.  A Configuration Example

   The following is an XML example using the OSPF SR YANG module, and
   RFC 9020.

   Note: '\' line wrapping per [RFC8792].

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   <?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>
                 <interfaces>
                   <interface>
                     <name>eth0</name>
                     <segment-routing xmlns="urn:ietf:params:xml:ns\
                       :yang:ietf-ospf-sr">
                       <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">
               <enabled>true</enabled>
             </segment-routing>
             <protocol-srgb xmlns="urn:ietf:params:xml:ns:yang:\
               ietf-ospf-sr">
               <srgb>
                 <lower-bound>4000</lower-bound>
                 <upper-bound>5000</upper-bound>
               </srgb>
             </protocol-srgb>
           </ospf>
         </control-plane-protocol>
       </control-plane-protocols>
     </routing>

   The following is the same example using JSON format.

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   {
     "routing": {
       "router-id": "1.1.1.1",
       "control-plane-protocols": {
         "control-plane-protocol": {
           "type": "ospf:ospfv2",
           "name": "OSPFv2",
           "ospf": {
             "areas": {
               "area": {
                 "area-id": "0.0.0.0",
                 "interfaces": {
                   "interface": {
                     "name": "eth0",
                     "segment-routing": {
                       "adjacency-sid": {
                         "adj-sids": {
                           "value": 3888
                         }
                       }
                     }
                   }
                 }
               }
             },
             "segment-routing": {
               "enabled": true
             },
             "protocol-srgb": {
               "srgb": {
                 "lower-bound": 4000,
                 "upper-bound": 5000
               }
             }
           }
         }
       }
     }
   }

Appendix B.  Contributors' Addreses

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   Dean Bogdanovic
   Alef

   EMail: ivandean@gmail.com

   Kiran Koushik Agrahara Sreenivasa
   Verizon Wireless
   Austin, TX  78681
   USA

   EMail: KiranKoushik.AgraharaSreenivasa@verisonwireless.com

Authors' Addresses

   Yingzhen Qu
   Futurewei Technologies
   2330 Central Expressway
   Santa Clara, CA 95050
   United States of America
   Email: yingzhen.ietf@gmail.com

   Acee Lindem
   LabN
   301 Midenhall Way
   Cary, NC 27513
   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
   The MITRE Corporation
   Email: ingwherchen@mitre.org

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