<?xml version='1.0' encoding='utf-8'?> encoding='UTF-8'?>

<!DOCTYPE rfc [
  <!ENTITY nbsp    "&#160;">
  <!ENTITY zwsp   "&#8203;">
  <!ENTITY nbhy   "&#8209;">
  <!ENTITY wj     "&#8288;">
]>
<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc tocdepth="3"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes" ?>
<?rfc compact="yes" ?>
<?rfc subcompact="no" ?>

<rfc xmlns:xi="http://www.w3.org/2001/XInclude" docName="draft-ietf-isis-sr-yang-31" number="9902" ipr="trust200902" category="std" consensus="true" obsoletes="" updates="" submissionType="IETF" xml:lang="en" tocInclude="true" tocDepth="3" symRefs="true" sortRefs="true" version="3">
  <!-- xml2rfc v2v3 conversion 3.13.1 -->

  <front>
    <title abbrev="IS-IS SR MPLS YANG">A YANG Data Model for IS-IS Segment Routing over the MPLS Data Plane</title>
    <seriesInfo name="Internet-Draft" value="draft-ietf-isis-sr-yang-31"/> name="RFC" value="9902"/>
    <author fullname="Stephane Litkowski" initials="S" surname="Litkowski">
      <organization>Cisco Systems</organization>
      <address>
        <email>slitkows.ietf@gmail.com</email>
      </address>
    </author>
    <author fullname="Yingzhen Qu" initials="Y" surname="Qu">
      <organization>Futurewei Technologies</organization>
      <address>
        <email>yingzhen.ietf@gmail.com</email>
      </address>
    </author>
  <author fullname="Acee Lindem" initials="A." surname="Lindem">
    <organization>LabN Consulting, L.L.C.</organization>
    <address>
      <email>acee.ietf@gmail.com</email>
    </address>
  </author>
    <author fullname="Ing-Wher Chen" initials="I." surname="Chen">
      <organization>The MITRE Corporation</organization>
      <address>
        <email>ingwherchen@mitre.org</email>
      </address>
    </author>
    <author fullname="Jeff Tantsura" initials="J" surname="Tantsura">
      <organization>Nvidia</organization>
      <address>
        <email>jefftant.ietf@gmail.com</email>
      </address>
    </author>
    <date/>
    <area/>
    <workgroup>LSR Working Group</workgroup>
    <date month="November" year="2025"/>
    <area>RTG</area>
    <workgroup>lsr</workgroup>

<!-- [rfced] Please insert any keywords (beyond those that appear in
the title) for use on https://www.rfc-editor.org/search. -->

<keyword>example</keyword>

    <abstract>
      <t>This document defines a YANG data model that can be used to
        manage IS-IS Extensions extensions for Segment Routing over the MPLS data plane.
      </t>
    </abstract>
  </front>

  <middle>
    <section anchor="introduction" toc="default" numbered="true">
      <name>Overview</name>
      <t>This document defines a device YANG data model <xref target="RFC7950"/> that can be used to
   manage IS-IS Extensions extensions for Segment Routing <xref target="RFC8667" format="default"/> over the MPLS data plane.
   It is an augmentation to the IS-IS YANG data model <xref target="RFC9130" format="default"/>.</t>
      <t> The YANG data model in this document conforms to the Network Management
      Datastore Architecture (NMDA) <xref target="RFC8342" format="default"/>.</t>
      <section numbered="true" toc="default">
        <name>Requirements Language</name>
        <t>The

<!--[rfced] We note that BCP 14 key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
        NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
        "MAY", and "OPTIONAL" are not used in this document are to be interpreted as
        described document.
Therefore, we have removed the keywords paragraph in BCP 14 <xref target="RFC2119" format="default"/> <xref target="RFC8174" format="default"/>
        when, Section 1.1 and only when, they appear in all capitals, as shown here.</t>
      </section>
the YANG module. We have also removed the references to RFCs 2119 and 8174.
-->

      <section numbered="true" toc="default">
        <name>Tree Diagrams</name>
        <t>This document uses the graphical representation of a data model as
          defined in <xref target="RFC8340" format="default"/>.</t>
      </section>
    </section>

<!--[rfced] This text in Section 2 reflects text in Section 1. As it is
repeating information, may we remove this text from Section 2?

Original (Section 1):
   This document defines a device YANG data model [RFC7950] that can be
   used to manage IS-IS Extensions for Segment Routing [RFC8667] over
   the MPLS data plane.  It is an augmentation to the IS-IS YANG data
   model [RFC9130].

Original (Section 2):
   This document defines a YANG data model for IS-IS Extensions for
   Segment Routing over the MPLS data plane.  It is an augmentation of
   the IS-IS base model.
-->

    <section anchor="design" toc="default" numbered="true">
      <name>Design of the IS-IS MPLS Segment Routing Module</name>
      <t>This document defines a YANG data model for IS-IS Extensions extensions for Segment Routing over the MPLS data plane.  It
   is an augmentation of the IS-IS base model.</t>
      <t>The IS-IS SR MPLS YANG module requires support for the base segment routing Segment Routing
   module <xref target="RFC9020" format="default"/>, which defines the global segment
   routing Segment
   Routing management independent of any specific routing protocol configuration, and support of the IS-IS base model <xref target="RFC9130" format="default"/> format="default"/>,
   which defines the basic IS-IS configuration and state.</t>

   <t>The ietf-isis-sr-mpls "ietf-isis-sr-mpls" data module model defines both the data nodes to configure
    IS-IS segment routing Segment Routing MPLS extensions and the additions to the IS-IS Link
    State Protocol Data Units (LSPs) necessary to support MPLS segment routing.</t> Segment Routing.</t>

        <section anchor="spring-activation" toc="default" numbered="true">
          <name>Segment Routing Activation</name>
          <t>
		Activation of IS-IS SR MPLS is done by setting the "enable" leaf to true.
		This triggers advertisement of SR MPLS extensions based on the configuration parameters that have been
		set up using the base segment routing Segment Routing module.
          </t>
        </section>

        <section anchor="spring-ms" toc="default" numbered="true">
          <name>Advertising Mapping Server Policy</name>
          <t>
		The base segment routing Segment Routing module defines mapping server policies.
		By default, IS-IS will not advertise or process any mapping server entry.
		The IS-IS SR MPLS module allows the advertisement of one or multiple mapping server policies through the "bindings/advertise/policies" leaf-list.
		The "bindings/receive" leaf controls the reception and process of mapping server entries.
          </t>
        </section>

        <section anchor="spring-ipfrr" toc="default" numbered="true">
          <name>IP Fast Reroute</name>
          <t>
		The IS-IS SR MPLS model module augments the fast-reroute Fast Reroute (FRR) container under interface.
		It brings the ability to activate TI-LFA (Topology Topology Independent LFA) Loop-Free Alternate (TI-LFA) and also enhances remote Remote LFA (RLFA) to use
		segment-routing
		Segment Routing tunneling instead of LDP.
          </t>
        </section>
      </section>

      <section anchor="isis-sr-yang" toc="default" numbered="true">
        <name>IS-IS MPLS Segment Routing over MPLS YANG Module</name>

<!--[rfced] RFC 8402 is only cited in the YANG module. May we add a
citation to RFC 8402 to the this sentence preceding the YANG module
as well as add a reference in the Normative References section?

Original:
   [RFC6991], [RFC8102], [RFC8294], [RFC8349], [RFC8667], [RFC9020],
   [RFC9130], and [I-D.ietf-rtgwg-segment-routing-ti-lfa] are referenced
   in the YANG module.

Perhaps:
   [RFC6991], [RFC8102], [RFC8294], [RFC8349], [RFC8402], [RFC8667],
   [RFC9020], [RFC9130], and [RFC9855] are referenced
   in the YANG module.
   ...
   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.
-->

        <t>
          <xref target="RFC6991"/>, <xref target="RFC8102"/>, <xref target="RFC8294"/>, <xref target="RFC8349"/>,
          <xref target="RFC8667"/>, <xref target="RFC9020"/>,  <xref target="RFC9130"/>,
          and <xref target="I-D.ietf-rtgwg-segment-routing-ti-lfa" target="RFC9855" format="default"/>
          are referenced in the YANG module.
        </t>

<!--[rfced] These two sentences in the description clauses of the YANG
module are phrased similarly. Should they be rephrased to match? If yes,
should "IP" appear before "FRR" or before "interface"?

Original:
   This augments ISIS interface level-1 IP FRR with TILFA.
   ...
   This augments ISIS IP interface level-2 FRR with TILFA.
-->

<!--[rfced] We have updated this description text in the YANG module for
clarity. Please review and confirm that the intended meaning has not
been altered.

Original:
   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.

Current:
   A path providing a node with a disjoint path for SRLG
   links from the primary path will be selected over
   a path that doesn't provide an SRLG disjoint path.
-->

<figure>
    <artwork><![CDATA[
<CODE BEGINS> file "ietf-isis-sr-mpls@2025-05-06.yang"
    <sourcecode name="ietf-isis-sr-mpls@2025-11-21.yang" type="yang" markers="true"><![CDATA[
module ietf-isis-sr-mpls {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls";
  prefix isis-sr-mpls;

  import ietf-routing {
    prefix rt;
    reference
      "RFC 8349: A YANG Data Model for Routing
                  Management (NMDA Version)";
  }
  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 6991: Common YANG Data Types";
  }
  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-isis {
    prefix isis;
    reference
      "RFC 9130: YANG Data Model for IS-IS Protocol";
  }
  import iana-routing-types {
    prefix iana-rt-types;
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area";
  }
  import ietf-routing-types {
    prefix rt-types;
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area";
  }

  organization
    "IETF LSR - Link State Routing Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/lsr/>
     WG List:  <mailto:lsr@ietf.org>

     Author:    Stephane Litkowski
                <mailto:slitkows.ietf@gmail.com>
     Author:    Yingzhen Qu
                <mailto:yingzhen.ietf@gmail.com>
     Author:    Acee Lindem
                <mailto:acee.ietf@gmail.com>
     Author:    Ing-Wher Chen
                <mailto:ingwherchen@mitre.org>
     Author:    Jeff Tantsura
                <mailto:jefftant.ietf@gmail.com>
    ";
  description
    "The YANG module defines the generic configuration and
     operational state for Segment Routing ISIS IS-IS extensions for the
     MPLS data plane.

     This YANG data 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).

     This version of this YANG module is part of RFC XXXX
     (https://www.rfc-editor.org/info/rfcXXXX); 9902
     (https://www.rfc-editor.org/info/rfc9902); 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; 9902;
     see the RFC itself for full legal notices.";

  // RFC Ed.: Replace XXXX with actual RFC number and remove
  // this note

  revision 2025-05-06 2025-11-21 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: 9902: A YANG Data Model for IS-IS Segment Routing over
                 the MPLS Data Plane";
  }

  // RFC Ed.: Replace XXXX with actual RFC number.
  // Also, replace '2025-04-22' with the module publication date
  // in the format (YYYY-MM-DD) and remove this note.

  /* Features */

  feature remote-lfa-sr {
    description
      "Enhance rLFA RLFA to use SR path.";
    reference
      "RFC 8102: Remote-LFA Node Protection and Manageability";
  }

  feature ti-lfa {
    description
      "Topology-Independent
      "Topology Independent Loop-Free Alternate (TI-LFA)
       computation using segment routing."; Segment Routing.";
    reference
      "draft-ietf-rtgwg-segment-routing-ti-lfa -
       Topology-Independent
      "RFC 9855: Topology Independent Fast Reroute using Using Segment
       Routing";
  }

  /* Identities */

  identity sr-capability {
    description
      "Base identity for ISIS IS-IS SR-Capabilities sub-TLV flags"; flags.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing";
  }

  identity mpls-ipv4 {
    base sr-capability;
    description
      "If set, then the router is capable of
       processing SR MPLS encapsulated SR-MPLS-encapsulated IPv4 packets
       on all interfaces.";
  }

  identity mpls-ipv6 {
    base sr-capability;
    description
      "If set, then the router is capable of
       processing SR MPLS encapsulated SR-MPLS-encapsulated IPv6 packets
       on all interfaces.";
  }

  identity prefix-sid-flag {
    description
      "Base identity for prefix SID Prefix Segment Identifier (Prefix-SID)
       sub-TLV flags.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity r-flag {
    base prefix-sid-flag;
    description
      "Re-advertisement Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity n-flag {
    base prefix-sid-flag;
    description
      "Node-SID Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity p-flag {
    base prefix-sid-flag;
    description
      "No-PHP (No Penultimate Hop-Popping) Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity e-flag {
    base prefix-sid-flag;
    description
      "Explicit NULL Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity v-flag {
    base prefix-sid-flag;
    description
      "Value Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity l-flag {
    base prefix-sid-flag;
    description
      "Local Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
  }

  identity adj-sid-flag {
    description
      "Base identity for Adj-SID Adjacency Segment Identifier (Adj-SID)
       sub-TLV flags.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity f-flag {
    base adj-sid-flag;
    description
      "Address-Family flag."; Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity b-flag {
    base adj-sid-flag;
    description
      "Backup flag."; Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity vi-flag {
    base adj-sid-flag;
    description
      "Value/Index flag Flag - corresponds to V-Flag in reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity lg-flag {
    base adj-sid-flag;
    description
      "Local/Global flag Flag - corresponds to L-Flag in reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity s-flag {
    base adj-sid-flag;
    description
      "Set flag Flag - corresponds to S-Flag in reference.."; reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity pe-flag {
    base adj-sid-flag;
    description
      "Persistent flag Flag - corresponds to P-Flag in reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
  }

  identity sid-binding-flag {
    description
      "Base identity for sid binding tlv SID Binding TLV flags.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  identity af-flag {
    base sid-binding-flag;
    description
      "Address-Family flag Flag - corresponds to F-Flag in reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  identity m-flag {
    base sid-binding-flag;
    description
      "Mirror Context flag."; Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  identity sf-flag {
    base sid-binding-flag;
    description
      "S flag.
      "S-Flag.  If set, the binding label Label Binding TLV should be flooded
       across the entire routing domain - corresponds to S-Flag in
       reference.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  identity d-flag {
    base sid-binding-flag;
    description
      "Leaking flag."; Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  identity a-flag {
    base sid-binding-flag;
    description
      "Attached flag."; Flag.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.4";
  }

  /* Groupings */

  grouping sid-tlv-encoding {
    description
      "SID TLV Encoding - 20-bit label or 32-bit SID index whose
       interpretation is dependent on the TLV length (3 for an
       MPLS label or 4 for a 32-bit value) or the TLV V-Flag and
       L-Flag settings:

        If the V-Flag is set to 0 and L-Flag is set to 0:
        The SID/Index/Label field is a 4-octet index defining
        the offset in the SID/Label space advertised by this
        router.

        If the V-Flag is set to 1 and L-Flag is set to 1:
        The
        ID/Index/Label SID/Index/Label field is a 3-octet local label where the
        20 rightmost bits are used for encoding the label value.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing,
       Section 2.1.1.1";
    choice sid {
      case sid-label {
        leaf label-value {
          type uint32 {
            range "0 .. 1048575";
          }
          description
            "A 20-bit MPLS Label"; label.";
        }
      }
      case sid-index {
        leaf index-value {
          type uint32;
          description
            "Index into a label space advertised by this router.";
        }
      }
      description
        "Choice of either a 20-bit MPLS label or 32-bit index into
         an advertised label space.";
    }
  }

  grouping sr-capability {
    description
      "SR capability
      "SR-Capability grouping.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.1";
    container sr-capability {
      description
        "SR Capability Flags.";
        "SR-Capability flags.";
      leaf-list sr-capability-flag {
        type identityref {
          base sr-capability;
        }
        description
          "SR Capability
          "SR-Capability sub-TLV flags.";
      }
      container global-blocks {
        description
          "Segment Routing Global Blocks.";
        list global-block {
          description
            "Segment Routing Global Block.";
          leaf range-size {
            type rt-types:uint24;
            description
              "The SID range.";
          }
          uses sid-tlv-encoding;
        }
      }
    }
  }

  grouping sr-algorithm {
    description
      "SR algorithm grouping.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.2";
    container sr-algorithms {
      description
        "All SR algorithms.";
      leaf-list sr-algorithm {
        type identityref {
          base sr-cmn:prefix-sid-algorithm;
        }
        description
          "The Segment Routing (SR) algorithms that the router is
           currently using.";
      }
    }
  }

  grouping srlb {
    description
      "SR Local Block grouping.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.3";
    container local-blocks {
      description
        "List of SRLBs."; Segment Routing Local Blocks (SRLBs).";
      list local-block {
        description
          "Segment Routing Local Block.";
        leaf range-size {
          type rt-types:uint24;
          description
            "The SID range.";
        }
        uses sid-tlv-encoding;
      }
    }
  }

  grouping srms-preference {
    description
      "The SRMS preference SR Mapping Server (SRMS) Preference TLV is used to
       advertise a preference associated with the node that acts as
       an SR Mapping Server."; SRMS.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 3.4";
    container srms-preference {
      description
        "SRMS Preference TLV.";
      leaf preference {
        type uint8;
        description
          "SRMS preference Preference TLV, value from 0 to 255 with
           255 being the most preferred.";
      }
    }
  }

  grouping adjacency-state {
    description
      "This grouping extends adjacency state.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
    list adjacency-sid {
      config false;
      description
        "List of adjacency Segment IDs.";
      leaf value {
        type uint32;
        description
          "Value of the Adj-SID.";
      }
      leaf address-family {
        type iana-rt-types:address-family;
        description
          "Address-family associated with the
           segment ID"; ID.";
      }
      leaf weight {
        type uint8;
        description
          "Weight associated with
           the adjacency SID.";
      }
      leaf protection-requested {
        type boolean;
        description
          "Describe if the adjacency SID
           must be protected.";
      }
    }
  }

  grouping prefix-sid-sub-tlv {
    description
      "This grouping defines segment routing prefix segment
       identifier (prefix-sid) sub-tlv."; the Segment Routing Prefix Segment
       Identifier (Prefix-SID) sub-TLV.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.1";
    container prefix-sid-sub-tlvs {
      description
        "PrefixSID sub-tlvs.";
        "Prefix-SID sub-TLVs.";
      list prefix-sid-sub-tlv {
        description
          "List of prefix-sid sub-tlvs."; Prefix-SID sub-TLVs.";
        container prefix-sid-flags {
          description
            "Describes flags associated with the
             segment ID.";
          leaf-list flag {
            type identityref {
              base prefix-sid-flag;
            }
            description
              "Prefix SID
              "Prefix-SID sub-TLV flags.";
          }
        }
        leaf algorithm {
          type identityref {
            base sr-cmn:prefix-sid-algorithm;
          }
          description
            "Algorithm to be used for path computation.";
        }
        uses sid-tlv-encoding;
      }
    }
  }

  grouping adjacency-segment-id {
    description
      "This grouping defines segment routing Segment Routing extensions
       for adjacencies.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing, Section 2.2";
    container adj-sid-sub-tlvs {
      description
        "Adj-SID optional sub-TLVs.";
      list adj-sid-sub-tlv {
        description
          "List of segments.";
        container adj-sid-flags {
          description
            "Adj-SID sub-TLV flags.";
          leaf-list flag {
            type identityref {
              base adj-sid-flag;
            }
            description
              "Adj-SID sub-TLV flags list.";
          }
        }
        leaf weight {
          type uint8;
          description
            "The value represents the weight of the Adj-SID
             for the purpose of load balancing.";
        }
        leaf neighbor-id {
          type isis:system-id;
          description
            "Describes the system ID of the neighbor
             associated with the SID value.  This is only
             used on LAN adjacencies.";
        }
        uses sid-tlv-encoding;
      }
    }
  }

  grouping sid-binding-tlv {
    description
      "SID/Label binding Binding TLV, type 149.";
    reference
      "RFC 8667: IS-IS Extensions for Segment Routing,
       Section 2.4";
    leaf prefix {
      type inet:ip-prefix;
      description
        "The prefix represents the Forwarding Equivalence
         Class at the tail end of the advertised path.";
    }
    leaf range {
      type uint16;
      description
        "Provides the ability to specify a range of addresses
         and their associated prefix-sids."; Prefix-SIDs.";
    }
    container sid-binding-flags {
      description
        "Binding TLV flags.";
      leaf-list flag {
        type identityref {
          base sid-binding-flag;
        }
        description
          "SID Binding TLV flags.";
      }
    }
    list prefix-sid-sub-tlvs {
      description
        "List of prefix-sid sub-tlvs."; Prefix-SID sub-TLVs.";
      reference
        "RFC 8667: IS-IS Extensions for Segment Routing,
         Section 2.4.4";
      uses prefix-sid-sub-tlv;
    }
    list sid-sub-tlv {
      description
        "List of prefix-sid sub-tlvs."; Prefix-SID sub-TLVs.";
      reference
        "RFC 8667: IS-IS Extensions for Segment Routing,
         Section 2.4.5";
      uses sid-tlv-encoding;
    }
    uses isis:unknown-tlvs;
  }

  /* Configuration */

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis" {
    when "derived-from-or-self(../rt:type, 'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol configuration
       with segment routing Segment Routing for the MPLS data plane.";
    uses sr-mpls:sr-control-plane;
    container protocol-srgb {
      if-feature "sr-mpls:protocol-srgb";
      description
        "Per-protocol Segment Routing Global Block (SRGB).";
      reference
        "RFC 8402: Segment Routing Architecture, Section 2";
      uses sr-cmn:srgb;
    }
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface" {
    when "derived-from-or-self(../../../rt:type, 'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol configuration
       with segment routing."; Segment Routing.";
    uses sr-mpls:igp-interface {
      augment "segment-routing/adjacency-sid/adj-sids" {
        when "../../../isis:interface-type = 'broadcast'" {
          description
            "This augments the broadcast interface.";
        }
        description
          "This augments the LAN interface adj-sid with system-id.";
        leaf neighbor-system-id {
          type isis:system-id;
          mandatory true;
          description
            "Neighbor system ID.";
        }
      }
    }
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface"
        + "/isis:fast-reroute/isis:lfa" {
    when "derived-from-or-self(../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS interface IP FRR with TILFA."; TI-LFA.";
    container ti-lfa {
      if-feature "ti-lfa";
      description
        "Topology Independent Loop Free Loop-Free Alternate
         (TI-LFA) support.";
      leaf enabled {
        type boolean;
        default "false";
        description
          "Enables TI-LFA computation.";
      }
      container selection-tie-breakers {
        description
          "Configure path selection tie-breakers and their
           respective priorities for the TI-LFA computation.";
        container node-protection {
          presence "Presence of container enables the node
                    protection tie-breaker"; tie-breaker.";
          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.";
          leaf priority {
            type uint8;
            default "128";
            description
              "Priority for node protection tie-breaker with
               a lower priority being more preferred.";
          }
        }
        container srlg-disjoint {
          presence "Presence of container enables the SRLG
                    disjoint tie-breaker"; tie-breaker.";
          description
            "Enable SRLG (Shared Shared Resource Link Group) Group (SRLG)
             disjoint as a TI-LFA path selection tie-breaker.
             A path providing a node with a disjoint path for SRLG
             links from the primary path will be selected over
             one
             a path that doesn't provide an SRLG disjoint path.";
          leaf priority {
            type uint8;
            default "128";
            description
              "Priority for SRLG disjoint tie-breaker with
               a lower priority being more preferred.";
          }
        }
      }
    }
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface"
        + "/isis:fast-reroute/isis:lfa/isis:level-1" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS interface level-1 IP FRR with TILFA.";
       TI-LFA.";
    container ti-lfa {
      if-feature "ti-lfa";
      description
        "TI-LFA configuration.";
      leaf enabled {
        type boolean;
        default "false";
        description
          "Enables TI-LFA computation.";
      }
    }
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface"
        + "/isis:fast-reroute/isis:lfa/isis:level-2" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS IP interface level-2 FRR with TILFA.";
       TI-LFA.";
    container ti-lfa {
      if-feature "ti-lfa";
      description
        "TI-LFA configuration.";
      leaf enabled {
        type boolean;
        default "false";
        description
          "Enables TI-LFA computation.";
      }
    }
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface"
        + "/isis:fast-reroute/isis:lfa/isis:remote-lfa" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS remoteLFA config the IS-IS Remote LFA configuration with
       use of segment-routing the Segment Routing path.";
    leaf use-segment-routing-path {
      if-feature "remote-lfa-sr";
      type boolean;
      default "false";
      description
        "Force remote Remote LFA to use segment routing the Segment Routing path instead of
         LDP path.  The value of this leaf is in effect only when
         remote-lfa is enabled.";
    }
  }

  /* Operational states */

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:interfaces/isis:interface"
        + "/isis:adjacencies/isis:adjacency" {
    when "derived-from-or-self(../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol configuration
       with segment routing."; Segment Routing.";
    uses adjacency-state;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:router-capabilities/isis:router-capability" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB Link State Database (LSDB)
       router capability.";
    uses sr-capability;
    uses sr-algorithm;
    uses srlb;
    uses srms-preference;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:extended-is-neighbor/isis:neighbor/isis:instances"
        + "/isis:instance" {
    when "derived-from-or-self(../../../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB neighbor.";
    uses adjacency-segment-id;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:mt-is-neighbor/isis:neighbor/isis:instances"
        + "/isis:instance" {
    when "derived-from-or-self(../../../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB neighbor.";
    uses adjacency-segment-id;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:extended-ipv4-reachability/isis:prefixes" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB prefix.";
    uses prefix-sid-sub-tlv;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:mt-extended-ipv4-reachability/isis:prefixes" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB prefix.";
    uses prefix-sid-sub-tlv;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:ipv6-reachability/isis:prefixes" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB prefix.";
    uses prefix-sid-sub-tlv;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp"
        + "/isis:mt-ipv6-reachability/isis:prefixes" {
    when "derived-from-or-self(../../../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB prefix.";
    uses prefix-sid-sub-tlv;
  }

  augment "/rt:routing/"
        + "rt:control-plane-protocols/rt:control-plane-protocol"
        + "/isis:isis/isis:database/isis:levels/isis:lsp" {
    when "derived-from-or-self(../../../../rt:type,"
       + "'isis:isis')" {
      description
        "This augments ISIS the IS-IS routing protocol when used"; used.";
    }
    description
      "This augments ISIS the IS-IS protocol LSDB.";
    container sid-binding-tlvs {
      description
        "List of sid/label binding SID/Label Binding TLVs.";
      list sid-binding-tlv {
        key "prefix";
        description
          "Sid/label binding
          "SID/Label Binding TLV, type 149.";
        uses sid-binding-tlv;
      }
    }
    container mt-sid-binding-tlvs {
      description
        "List of multi-topology sid/label binding Multi-Topology SID/Label Binding TLVs.";
      list mt-sid-binding-tlv {
        key "prefix mt-id";
        description
          "Multi-Topology SID/Label binding Binding TLV, type 150.";
        reference
          "RFC 8667: IS-IS Extensions for Segment Routing,
           Section 2.5";
        uses sid-binding-tlv;
        leaf mt-id {
          type uint16;
          description
            "A 12-bit field containing the non-zero ID
             of the topology.";
        }
      }
    }
  }
}
<CODE ENDS>
]]></artwork>
]]></sourcecode>
</figure>

</section>

<section anchor="Security" toc="default" numbered="true">
  <name>Security Considerations</name>

<!--[rfced] FYI, we have made some updates to the Security Considerations to
match Section 3.7 of draft-ietf-netmod-rfc8407bis-28. Please let us know
if any further updates are needed. We note some differences, specifically:

a) Should this sentence from the template be added? "There are no particularly sensitive RPC or action operations."

b) These paragraphs do not appear in the template. Please confirm they should remain.

Original:
   The ability to disable or enable IS-IS Segment Routing support and/or
   change Segment Routing configurations can result in a Denial-of-
   Service (DoS) attack, as this may cause traffic to be dropped or
   misrouted.  Please refer to Section 5 of [RFC8667] for more
   information on Segment Routing extensions.
   ...
   Unauthorized access to any data node of these subtrees can disclose
   the operational state information of IS-IS protocol on a device.
-->

<!-- DNE begins -->
<t>This section is modeled after the template described in <xref
target="I-D.ietf-netmod-rfc8407bis" section="3.7" sectionFormat="of"/>.</t>
  <t>
    The ietf-isis-sr-mpls "ietf-isis-sr-mpls" YANG module defines a data model that is
   designed to be accessed via YANG-based management protocols, such as
   NETCONF <xref target="RFC6241"/> and RESTCONF <xref target="RFC8040"/>. These
   YANG-based management protocols (1) have to use a secure transport layer
   (e.g., SSH <xref target="RFC4252"/>, TLS <xref target="RFC8446"/>, and QUIC <xref target="RFC9000"/>) and (2) have
   to use mutual authentication.
  </t>
  <t>
    The Network Configuration Access Control Model (NACM) <xref target="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.
  </t>
  <t>
    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:
  </t>
<!-- DNE ends -->
      <ul empty="true" spacing="normal">
        <li>/isis:isis/segment-routing</li>
        <li>/isis:isis/protocol-srgb</li>
        <li>/isis:isis/isis:interfaces/isis:interface/segment-routing</li>
        <li>/isis:isis/isis:interfaces/isis:interface/isis:fast-reroute/ti-lfa</li>
      </ul>

      <t>The ability to disable or enable IS-IS Segment Routing support and/or change
        Segment Routing configurations can result in a Denial-of-Service (DoS) attack,
        as this may cause traffic to be dropped or misrouted. Please refer to Section 5
        of
      <xref target="RFC8667"/> target="RFC8667" section="5"/> for more information on Segment Routing extensions.</t>
<!-- DNE begins -->
      <t>Some of the readable data nodes in the modules 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:
      </t>
<!-- DNE ends -->
      <ul empty="true" spacing="normal">
        <li>/isis:router-capabilities/sr-capability</li>
        <li>/isis:router-capabilities/sr-algorithms</li>
        <li>/isis:router-capabilities/local-blocks</li>
        <li>/isis:router-capabilities/srms-preference</li>
        <li>And
        <li>and the augmentations to the ISIS link state database.</li> IS-IS Link State Database.</li>
      </ul>
      <t>Unauthorized access to any data node of these subtrees can disclose
        the operational state information of the IS-IS protocol on a device.</t>
    </section>
    <section anchor="Acknowledgements" toc="default" numbered="true">
      <name>Acknowledgements</name>
      <t>
        The authors would like to thank Pushpasis Sarkar, Derek Yeung,Yi Yang
        for their major contributions to the draft. Also thank Reshad Rahman, Tom Petch,
        and Renato Westphal for their thorough reviews and helpful comments.
      </t>
      <t>
        The authors wish to thank Mohamed Boucadair and Ketan Talaulikar for
        extensive AD reviews for the IESG Telechat.  Thanks to Eric Vyncke
        and Mahesh Jethanandani for review comments.</t>
      <t>
        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 agreed to this document for Public Release,
        Distribution Unlimited, with Public Release Case Number 19-3033. This
        approval allows the MITRE employee to release contributions externally and
        does not assert authority to publish.
      </t>
    </section>
    <section anchor="IANA" toc="default" numbered="true">
      <name>IANA Considerations</name>
      <t>The IANA is requested to assign has assigned one new URI from in the
   IETF
   "IETF XML registry (<xref target="RFC3688"/>): Registry" <xref target="RFC3688"/>: </t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
	URI: urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls
	Registrant Contact: The IESG.
	XML: N/A,
   <dl spacing="compact" newline="false">
     <dt>URI:</dt><dd>urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls</dd>
     <dt>Registrant Contact:</dt><dd>The IESG.</dd>
     <dt>XML:</dt><dd>N/A; the requested URI is an XML namespace
  ]]></artwork> namespace</dd>
   </dl>
      <t>This document also requests registers one new YANG module name in the YANG "YANG Module Names Names" registry (<xref <xref target="RFC6020" format="default"/>):</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
	name: ietf-isis-sr-mpls
	namespace: urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls
	prefix: isis-sr-mpls
  maintained format="default"/>:</t>
   <dl spacing="compact" newline="false">
     <dt>Name:</dt><dd>ietf-isis-sr-mpls</dd>
     <dt>Maintained by IANA? N
	reference: RFC XXXX
  ]]></artwork> IANA?</dt><dd>N</dd>
     <dt>Namespace:</dt><dd>urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls</dd>
     <dt>Prefix:</dt><dd>isis-sr-mpls</dd>
     <dt>Reference:</dt><dd>RFC 9902</dd>
   </dl>
    </section>
  </middle>
  <back>
    <displayreference target="I-D.ietf-netmod-rfc8407bis" to="YANG-GUIDE"/>
    <references>
      <name>References</name>
    <references>
      <name>Normative References</name>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4252.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6991.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7950.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6991.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8102.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7950.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8294.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8102.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8341.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8294.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8349.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8341.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8667.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9020.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8349.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9130.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8667.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9020.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9130.xml"/>
      <xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-rtgwg-segment-routing-ti-lfa.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9855.xml"/>

    </references>
    <references>
      <name>Informative References</name>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4252.xml"/>
      <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8040.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8040.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8446.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8446.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8792.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8792.xml"/>
      <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9000.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9000.xml"/>
      <xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-netmod-rfc8407bis.xml"/>
    </references>
  </references>

    <section numbered="true" toc="default">
        <name>A Configuration Example</name>
        <t>
          The following is an XML example using the ISIS IS-IS SR MPLS YANG module defined in this document.
          </t>
        <t>Note: '\' line wrapping per <xref target="RFC8792" format="default"/>. </t>
        <artwork name="" type="" align="left" alt=""><![CDATA[
        <sourcecode type="xml"><![CDATA[
<?xml version='1.0' encoding='UTF-8'?>
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
  <interface>
    <name>eth0</name>
    <admin-status>up</admin-status>
    <oper-status>up</oper-status>
    <if-index>1</if-index>
    <statistics>
      <discontinuity-time>2024-10-27T14:30:00Z</discontinuity-time>
    </statistics>
  </interface>
</interfaces>
<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:isis="urn:ietf:params:xml:ns:yang:ietf-isis">\
       isis:isis</type>
     <name>isis</name>
     <isis xmlns="urn:ietf:params:xml:ns:yang:ietf-isis">
       <system-id>1111.2222.3333</system-id>
       <area-address>49.0001.0000.0000.0001</area-address>
       <interfaces>
         <interface>
           <name>eth0</name>
           <segment-routing xmlns="urn:ietf:params:xml:ns:yang:\
             ietf-isis-sr-mpls">
             <adjacency-sid>
               <adj-sids>
                 <value>38888</value>
                 <neighbor-system-id>4444.5555.6666\
                 </neighbor-system-id>
               </adj-sids>
             </adjacency-sid>
           </segment-routing>
         </interface>
       </interfaces>
       <segment-routing xmlns="urn:ietf:params:xml:ns:yang:\
         ietf-isis-sr-mpls">
         <enabled>true</enabled>
       </segment-routing>
       <protocol-srgb xmlns="urn:ietf:params:xml:ns:yang:\
         ietf-isis-sr-mpls">
         <srgb>
           <lower-bound>4000</lower-bound>
           <upper-bound>5000</upper-bound>
         </srgb>
       </protocol-srgb>
       </isis>
    </control-plane-protocol>
 </control-plane-protocols>
</routing>
            ]]></artwork>
]]></sourcecode>

      <t>The following is the same example using JSON format.</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
      <sourcecode type="json"><![CDATA[
{
  "ietf-interfaces:interfaces": {
    "interface": [
      {
        "name": "eth0",
        "admin-status": "up",
        "oper-status": "up",
        "if-index": 1,
        "statistics": {
          "discontinuity-time": "2024-10-27T07:30:00-07:00"
        }
      }
    ]
  },
  "ietf-routing:routing": {
    "router-id": "1.1.1.1",
    "control-plane-protocols": {
      "control-plane-protocol": [
        {
          "type": "ietf-isis:isis",
          "name": "isis",
          "ietf-isis:isis": {
            "system-id": "1111.2222.3333",
            "area-address": [
              "49.0001.0000.0000.0001"
            ],
            "interfaces": {
              "interface": [
                {
                  "name": "eth0",
                  "ietf-isis-sr-mpls:segment-routing": {
                    "adjacency-sid": {
                      "adj-sids": [
                        {
                          "value": 38888,
                          "neighbor-system-id": "4444.5555.6666"
                        }
                      ]
                    }
                  }
                }
              ]
            },
            "ietf-isis-sr-mpls:segment-routing": {
              "enabled": true
            },
            "ietf-isis-sr-mpls:protocol-srgb": {
              "srgb": [
                {
                  "lower-bound": 4000,
                  "upper-bound": 5000
                }
              ]
            }
          }
        }
      ]
    }
  }
}
  ]]></artwork>
]]></sourcecode>
</section>

    <section numbered="true" toc="default">
        <name>IS-IS MPLS Segment Routing Module Tree</name>
      <t>The figure below describes the overall structure of the ietf-isis-sr-mpls "ietf-isis-sr-mpls"
      YANG module:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
      <sourcecode type="yangtree"><![CDATA[
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis:
  +--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/isis:isis/isis:interfaces
          /isis: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-system-id    isis:system-id
        +--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/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute/isis: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/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute/isis:lfa/isis:level-1:
  +--rw ti-lfa {ti-lfa}?
     +--rw enabled?   boolean
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute/isis:lfa/isis:level-2:
  +--rw ti-lfa {ti-lfa}?
     +--rw enabled?   boolean
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface/isis:fast-reroute/isis:lfa
          /isis:remote-lfa:
  +--rw use-segment-routing-path?   boolean {remote-lfa-sr}?
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:interfaces
          /isis:interface/isis:adjacencies/isis:adjacency:
  +--ro adjacency-sid* []
     +--ro value?                  uint32
     +--ro address-family?         iana-rt-types:address-family
     +--ro weight?                 uint8
     +--ro protection-requested?   boolean
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:router-capabilities
          /isis:router-capability:
  +--ro sr-capability
  |  +--ro sr-capability-flag*   identityref
  |  +--ro global-blocks
  |     +--ro global-block* []
  |        +--ro range-size?          rt-types:uint24
  |        +--ro (sid)?
  |           +--:(sid-label)
  |           |  +--ro label-value?   uint32
  |           +--:(sid-index)
  |              +--ro index-value?   uint32
  +--ro sr-algorithms
  |  +--ro sr-algorithm*   identityref
  +--ro local-blocks
  |  +--ro local-block* []
  |     +--ro range-size?          rt-types:uint24
  |     +--ro (sid)?
  |        +--:(sid-label)
  |        |  +--ro label-value?   uint32
  |        +--:(sid-index)
  |           +--ro index-value?   uint32
  +--ro srms-preference
     +--ro preference?   uint8
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:extended-is-neighbor
          /isis:neighbor/isis:instances/isis:instance:
  +--ro adj-sid-sub-tlvs
     +--ro adj-sid-sub-tlv* []
        +--ro adj-sid-flags
        |  +--ro flag*   identityref
        +--ro weight?              uint8
        +--ro neighbor-id?         isis:system-id
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:mt-is-neighbor/isis:neighbor
          /isis:instances/isis:instance:
  +--ro adj-sid-sub-tlvs
     +--ro adj-sid-sub-tlv* []
        +--ro adj-sid-flags
        |  +--ro flag*   identityref
        +--ro weight?              uint8
        +--ro neighbor-id?         isis:system-id
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:extended-ipv4-reachability
          /isis:prefixes:
  +--ro prefix-sid-sub-tlvs
     +--ro prefix-sid-sub-tlv* []
        +--ro prefix-sid-flags
        |  +--ro flag*   identityref
        +--ro algorithm?           identityref
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:mt-extended-ipv4-reachability
          /isis:prefixes:
  +--ro prefix-sid-sub-tlvs
     +--ro prefix-sid-sub-tlv* []
        +--ro prefix-sid-flags
        |  +--ro flag*   identityref
        +--ro algorithm?           identityref
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:ipv6-reachability
          /isis:prefixes:
  +--ro prefix-sid-sub-tlvs
     +--ro prefix-sid-sub-tlv* []
        +--ro prefix-sid-flags
        |  +--ro flag*   identityref
        +--ro algorithm?           identityref
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp/isis:mt-ipv6-reachability
          /isis:prefixes:
  +--ro prefix-sid-sub-tlvs
     +--ro prefix-sid-sub-tlv* []
        +--ro prefix-sid-flags
        |  +--ro flag*   identityref
        +--ro algorithm?           identityref
        +--ro (sid)?
           +--:(sid-label)
           |  +--ro label-value?   uint32
           +--:(sid-index)
              +--ro index-value?   uint32
augment /rt:routing/rt:control-plane-protocols
          /rt:control-plane-protocol/isis:isis/isis:database
          /isis:levels/isis:lsp:
  +--ro sid-binding-tlvs
  |  +--ro sid-binding-tlv* [prefix]
  |     +--ro prefix                 inet:ip-prefix
  |     +--ro range?                 uint16
  |     +--ro sid-binding-flags
  |     |  +--ro flag*   identityref
  |     +--ro prefix-sid-sub-tlvs* []
  |     |  +--ro prefix-sid-sub-tlvs
  |     |     +--ro prefix-sid-sub-tlv* []
  |     |        +--ro prefix-sid-flags
  |     |        |  +--ro flag*   identityref
  |     |        +--ro algorithm?           identityref
  |     |        +--ro (sid)?
  |     |           +--:(sid-label)
  |     |           |  +--ro label-value?   uint32
  |     |           +--:(sid-index)
  |     |              +--ro index-value?   uint32
  |     +--ro sid-sub-tlv* []
  |     |  +--ro (sid)?
  |     |     +--:(sid-label)
  |     |     |  +--ro label-value?   uint32
  |     |     +--:(sid-index)
  |     |        +--ro index-value?   uint32
  |     +--ro unknown-tlvs
  |        +--ro unknown-tlv* []
  |           +--ro type?     uint16
  |           +--ro length?   uint16
  |           +--ro value?    yang:hex-string
  +--ro mt-sid-binding-tlvs
     +--ro mt-sid-binding-tlv* [prefix mt-id]
        +--ro prefix                 inet:ip-prefix
        +--ro range?                 uint16
        +--ro sid-binding-flags
        |  +--ro flag*   identityref
        +--ro prefix-sid-sub-tlvs* []
        |  +--ro prefix-sid-sub-tlvs
        |     +--ro prefix-sid-sub-tlv* []
        |        +--ro prefix-sid-flags
        |        |  +--ro flag*   identityref
        |        +--ro algorithm?           identityref
        |        +--ro (sid)?
        |           +--:(sid-label)
        |           |  +--ro label-value?   uint32
        |           +--:(sid-index)
        |              +--ro index-value?   uint32
        +--ro sid-sub-tlv* []
        |  +--ro (sid)?
        |     +--:(sid-label)
        |     |  +--ro label-value?   uint32
        |     +--:(sid-index)
        |        +--ro index-value?   uint32
        +--ro unknown-tlvs
        |  +--ro unknown-tlv* []
        |     +--ro type?     uint16
        |     +--ro length?   uint16
        |     +--ro value?    yang:hex-string
        +--ro mt-id                  uint16
]]></artwork>
]]></sourcecode>
      </section>
    <section anchor="Acknowledgements" toc="default" numbered="false">
      <name>Acknowledgements</name>
      <t>
        The authors would like to thank <contact fullname="Pushpasis Sarkar"/>, <contact fullname="Derek Yeung"/>, and <contact fullname="Yi Yang"/>
        for their major contributions to the document. Also thanks to  <contact fullname="Reshad Rahman"/>, <contact fullname="Tom Petch"/>,
        and <contact fullname="Renato Westphal"/> for their thorough reviews and helpful comments.
      </t>
      <t>
        The authors wish to thank <contact fullname="Mohamed Boucadair"/> and <contact fullname="Ketan Talaulikar"/> for
        extensive AD reviews for the IESG Telechat.  Thanks to <contact fullname="Éric Vyncke"/>
        and <contact fullname="Mahesh Jethanandani"/> for review comments.</t>
      <t>
        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 agreed to this document for Public Release,
        Distribution Unlimited, with Public Release Case Number 19-3033. This
        approval allows the MITRE employee to release contributions externally and
        does not assert authority to publish.
      </t>
    </section>
  </back>

<!--[rfced] Both the expansion and the acronym for the following terms are used
throughout the document. Would you like to update to using the expansion upon
first usage and the acronym for the rest of the document?

 Adjacency Segment Identifier, adjacency SID, adjacency Segment ID (Adj-SID)
 Link State Database (LSDB)
 Remote LFA (RLFA)
 Segment Routing (SR)
-->

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</rfc>