Internet-Draft OSPF SR MPLS YANG March 2025
Qu, et al. Expires 1 October 2025 [Page]
Workgroup:
Internet
Internet-Draft:
draft-ietf-ospf-sr-yang-37
Published:
Intended Status:
Standards Track
Expires:
Authors:
Y. Qu
Futurewei Technologies
A. Lindem
LabN Consulting, L.L.C.
J. Zhang
Juniper Networks
I. Chen
The MITRE Corporation

A YANG Data Model for OSPF Segment Routing for the MPLS Data Plane

Abstract

This document defines a YANG data module that can be used to manage OSPF Extensions for Segment Routing for the MPLS data plane.

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 1 October 2025.

Table of Contents

1. Overview

This document defines a YANG data model [RFC7950] that can be used to manage OSPFv2 extensions for Segment Routing [RFC8665] and OSPFv3 extensions for Segment Routing [RFC8666] for the MPLS data plane. 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", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

1.2. Tree Diagrams

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

2. OSPF Segment Routing YANG Data Module Scope

This document defines a model for OSPF Segment Routing Extensions for both OSPFv2 [RFC8665] and OSPFv3 [RFC8666].

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.

The ietf-ospf-sr-mpls data module defines both the data nodes to configure OSPF segment routing MPLS extensions and the additions to the OSPF Link State Advertisements (LSAs) necessary to support MPLS segment routing. The OSPF configuration includes:

The operational state (read-only) additions to specifc to OSPFv2 LSA include:

The operational state (read-only) additions to specifc to OSPFv3 LSA include:

3. OSPF Segment Routing YANG Module

[RFC2328], [RFC4915], [RFC5340], [RFC6991], [RFC8102], [RFC8294], [RFC8349], [RFC9587], and [I-D.ietf-rtgwg-segment-routing-ti-lfa] are referenced in the YANG data model.

<CODE BEGINS> file "ietf-ospf-sr-mpls@2025-03-30.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:   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).

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

     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 XXXX; 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.";

   reference
    "RFC XXXX";

  revision 2025-03-30 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A YANG Data Model for OSPF Segment Routing for
       the MPLS Data Plane";
  }

  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-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 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";
  }

  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.";
    reference
      "RFC 8665: OSPF Extensions for Segment Routing, Section 4
      RFC 8666: OSPFv3 Extensions for Segment Routing, Section 5";
  }

  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";
  }

  /* Groupings */
  grouping sid-tlv-encoding {
    description
      "SID TLV Encoding -  20-bit label or 32-bit SID 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 V-Flag is set to 1 and L-Flag is set to 1: The
        ID/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 5
       RFC 8666: OSPFv3 Extensions for Segment Routing, Section 3";
    leaf sid-raw {
      type uint32;
      description
        "Raw SID value - labels are in the rightmost 20 bits of
        the value";
    }
    choice sid-value {
      case label-sid {
        leaf label-value {
          type uint32 {
              range "0 .. 1048575";
          }
          description
            "A 20-bit MPLS Label";
        }
      }
      case offset-sid {
        leaf offset-value {
          type uint32;
          description
            "Offset into a label space advertised by this router.";
        }
      }
      description
        "Choice of either a 20-bit MPLS lable or 32-bit offset into
         an advertised label space.";
    }
  }


  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.";
      leaf length {
        type uint16;
        description
          "Length of the SID value. YANG model specification
           is necessary since it dictates the semantics of the
           SID.";
      }
      uses sid-tlv-encoding;
    }
  }

  grouping ospfv2-prefix-sid-sub-tlvs {
    description
      "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
            "Segment Identifier (SID) 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 algorithm {
          type identityref {
            base sr-cmn:prefix-sid-algorithm;
          }
          description
            "Algorithm associated with the prefix-SID.";
        }
        uses sid-tlv-encoding;
      }
    }
  }

  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 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;
      }
    }
  }

  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. Note that the order of advertised
         SID ranges is implementation dependent.";
      list sid-range-tlv {
        description
          "SID range TLV.";
        leaf range-size {
          type rt-types:uint24;
          description
            "SID range.";
        }
        uses sid-sub-tlv;
      }
    }
  }

  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. The return of a zero value would indicate
             an error.";
        }
        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. SR
       Mapping Server 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.";
      }
    }
  }

  grouping ospfv3-prefix-sid-sub-tlvs {
    description
      "Prefix Segment ID (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
            "Segment Identifier (SID) Flags.";
        }
        leaf algorithm {
          type identityref {
            base sr-cmn:prefix-sid-algorithm;
          }
          description
            "Algorithm associated with the prefix-SID.";
        }
        uses sid-tlv-encoding;
      }
    }
  }

  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
            "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;
      }
    }
  }

  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 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;
      }
    }
  }

  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 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;
      }
    }
  }

  /*
   * 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 for the MPLS data plane. The following semantic
       validation be performed for the configuration data:
        - Assure the binding policies prefixes do not overlapp.";
    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/ospf:interfaces/ospf:interface" {
    when "derived-from(/rt:routing/rt:control-plane-protocols/"
       + "rt:control-plane-protocol/rt:type, 'ospf:ospf')" {
      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 segment routing interface configuration.";
        }
        description
          "This augments LAN interface adj-sid with 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-FRR with TI-LFA.";
    container ti-lfa {
      if-feature "ti-lfa";
      description
        "Topology-Independent Loop Free Alternate
         (TI-LFA) support.";
      reference
        "draft-ietf-rtgwg-segment-routing-ti-lfa:
         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 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 (Sharsed 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
          "Configure path selection tie-breakers and their
           respective priorities for the TI-LFA computation.
           multiple tie-breakers and priorities configured may
           be configured.";
      }
    }
  }

  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 remote LFA.";
      reference
        "draft-ietf-rtgwg-segment-routing-ti-lfa:
         Topology-Independent Fast Reroute using Segment Routing";
    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.";
    }
  }

  /*
   * 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)";
    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;
      }
    }
    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;
      }
    }
  }

  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 Link-Scoped 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 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

The ietf-ospf-sr-mpls YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These protocols have to use a secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC [RFC9000] and have to use mutual authentication.

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

There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., "config true", which is the default). All writable data nodes are likely to be reasonably 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:

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 module ietf-ospf-sr-mpls augments 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.

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. Acknowledgements

The authors wish to thank Dean Bogdanovic and Kiran Koushik Agrahara Sreenivasa for their YANG model discussions.

The authors wish to thank 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.

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

The authors wish to thank Mohamed Boucadair for an extensive AD review for IESG Telechat.

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.

6. 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:

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

      name: ietf-ospf-sr-mpls
      namespace: urn:ietf:params:xml:ns:yang:ietf-ospf-sr-mpls
      prefix: ospf-sr-mpls
      maintained by IANA? N
      reference: RFC XXXX

7. References

7.1. Normative References

[I-D.ietf-rtgwg-segment-routing-ti-lfa]
Bashandy, A., Litkowski, S., Filsfils, C., Francois, P., Decraene, B., and D. Voyer, "Topology Independent Fast Reroute using Segment Routing", Work in Progress, Internet-Draft, draft-ietf-rtgwg-segment-routing-ti-lfa-21, , <https://datatracker.ietf.org/doc/html/draft-ietf-rtgwg-segment-routing-ti-lfa-21>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC2328]
Moy, J., "OSPF Version 2", STD 54, RFC 2328, DOI 10.17487/RFC2328, , <https://www.rfc-editor.org/info/rfc2328>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
[RFC4252]
Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH) Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252, , <https://www.rfc-editor.org/info/rfc4252>.
[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, , <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, , <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, , <https://www.rfc-editor.org/info/rfc6020>.
[RFC6991]
Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, , <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, , <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, , <https://www.rfc-editor.org/info/rfc7770>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <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, , <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, , <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, , <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, , <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, , <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, , <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, , <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, , <https://www.rfc-editor.org/info/rfc8666>.
[RFC9000]
Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Multiplexed and Secure Transport", RFC 9000, DOI 10.17487/RFC9000, , <https://www.rfc-editor.org/info/rfc9000>.
[RFC9020]
Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J. Tantsura, "YANG Data Model for Segment Routing", RFC 9020, DOI 10.17487/RFC9020, , <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, , <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, , <https://www.rfc-editor.org/info/rfc9587>.

7.2. Informative References

[RFC6241]
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <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, , <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, , <https://www.rfc-editor.org/info/rfc8342>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <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, , <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].

<?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-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>

The following is the same example using JSON format.

{
  "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. Full Tree Diagram

module: ietf-ospf-sr-mpls

 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 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: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-raw?              uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?    uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?              uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?    uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?              uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?    uint32
           +--:(offset-sid)
              +--ro offset-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-raw?              uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?    uint32
           +--:(offset-sid)
              +--ro offset-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-raw?              uint32
  |     +--ro (sid-value)?
  |        +--:(label-sid)
  |        |  +--ro label-value?    uint32
  |        +--:(offset-sid)
  |           +--ro offset-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-raw?              uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?    uint32
           +--:(offset-sid)
              +--ro offset-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-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-value?   uint32
  +--ro local-block-tlvs
  |  +--ro local-block-tlv* []
  |     +--ro range-size?    rt-types:uint24
  |     +--ro sid-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-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-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-value?   uint32
  +--ro local-block-tlvs
  |  +--ro local-block-tlv* []
  |     +--ro range-size?    rt-types:uint24
  |     +--ro sid-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-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-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-value?   uint32
  +--ro local-block-tlvs
  |  +--ro local-block-tlv* []
  |     +--ro range-size?    rt-types:uint24
  |     +--ro sid-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-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-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-value?   uint32
  +--ro local-block-tlvs
  |  +--ro local-block-tlv* []
  |     +--ro range-size?    rt-types:uint24
  |     +--ro sid-sub-tlv
  |        +--ro length?               uint16
  |        +--ro sid-raw?              uint32
  |        +--ro (sid-value)?
  |           +--:(label-sid)
  |           |  +--ro label-value?    uint32
  |           +--:(offset-sid)
  |              +--ro offset-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
          /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-raw?                   uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?         uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?                   uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?         uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?                   uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?         uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?                   uint32
        |     +--ro (sid-value)?
        |        +--:(label-sid)
        |        |  +--ro label-value?         uint32
        |        +--:(offset-sid)
        |           +--ro offset-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-raw?                   uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?         uint32
           +--:(offset-sid)
              +--ro offset-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-raw?                   uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?         uint32
           +--:(offset-sid)
              +--ro offset-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-raw?                   uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?         uint32
           +--:(offset-sid)
              +--ro offset-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-raw?                   uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?         uint32
           +--:(offset-sid)
              +--ro offset-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-raw?                   uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?         uint32
           +--:(offset-sid)
              +--ro offset-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-raw?              uint32
  |     +--ro (sid-value)?
  |        +--:(label-sid)
  |        |  +--ro label-value?    uint32
  |        +--:(offset-sid)
  |           +--ro offset-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-raw?              uint32
        +--ro (sid-value)?
           +--:(label-sid)
           |  +--ro label-value?    uint32
           +--:(offset-sid)
              +--ro offset-value?   uint32

Authors' Addresses

Yingzhen Qu
Futurewei Technologies
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Acee Lindem
LabN Consulting, L.L.C.
301 Midenhall Way
Cary, NC 27513
Jeffrey Zhang
Juniper Networks
10 Technology Park Drive
Westford, MA 01886
United States of America
Ing-Wher Chen
The MITRE Corporation