<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt"?>
<?rfc toc="yes"?>
<?rfc compact="no"?>
<?rfc subcompact="no"?>
<?rfc symrefs="yes" ?>
<?rfc sortrefs="yes"?>
<?rfc iprnotified="no"?>
<?rfc strict="yes"?>

<!DOCTYPE rfc [
 <!ENTITY nbsp    "&#160;">
 <!ENTITY zwsp   "&#8203;">
 <!ENTITY nbhy   "&#8209;">
 <!ENTITY wj     "&#8288;">
]>

<rfc ipr="trust200902" xmlns:xi="http://www.w3.org/2001/XInclude" category="std"
docName="draft-ietf-lsr-yang-isis-reverse-metric-06" number="9194" ipr="trust200902" obsoletes="" updates="" submissionType="IETF" consensus="true" tocInclude="true" xml:lang="en" symRefs="true" sortRefs="true" version="3">

<front>
  <title abbrev="YANG Module for IS-IS Reverse Metric">YANG Metric">A YANG Module for IS-IS Reverse Metric</title>
  <seriesInfo name="RFC" value="9194"/>

  <author initials='C.' surname='Hopps' fullname='Christian Hopps'><organization>LabN Hopps'>
   <organization>LabN Consulting, L.L.C.</organization><address><email>chopps@chopps.org</email></address></author>  <date/><abstract><t>This L.L.C.</organization>
   <address>
   <email>chopps@chopps.org</email>
   </address>
  </author>

<date month="February" year="2022"/>

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

<abstract>
<t>This document defines a YANG module for managing the reverse metric
extension to the Intermediate System to Intermediate System (IS-IS)
intra-domain routeing routing information exchange protocol (IS-IS).</t></abstract> protocol.
</t>
</abstract>
</front>
<middle>

<section title="Introduction"> numbered="true" toc="default">
<name>Introduction</name>
<t>This document defines a YANG module for managing the reverse metric
extension to IS-IS <xref target="RFC8500"/>, target="RFC8500"/> <xref target="ISO10589"/>. target="ISO-10589"/>. Please refer to <xref target="RFC8500"/> for the
description and definition of the functionality managed by this
module.</t>

<t>The YANG data model described in this document conforms to the
Network Management Datastore Architecture defined in <xref target="RFC8342"/>.</t>

</section>

<section title="YANG Management"> numbered="true" toc="default">
<name>YANG Management</name>
<section title="YANG Tree"> numbered="true" toc="default">
<name>YANG Tree</name>
<t>The following is the YANG tree diagram (<xref target="RFC8340"/>) <xref target="RFC8340"/> for the IS-IS
reverse metric extension additions.</t>

<artwork><![CDATA[

<sourcecode name="" type="yangtree"><![CDATA[
module: ietf-isis-reverse-metric
  augment /rt:routing/rt:control-plane-protocols
            /rt:control-plane-protocol/isis:isis:
    +--rw reverse-metric
       +--rw enable-receive?   boolean
  augment /rt:routing/rt:control-plane-protocols
            /rt:control-plane-protocol/isis:isis/isis:interfaces
            /isis:interface:
    +--rw reverse-metric
       +--rw metric?              isis:wide-metric
       +--rw flags
       |  +--rw whole-lan?           boolean
       |  +--rw allow-unreachable?   boolean
       +--rw exclude-te-metric?   boolean
       +--rw level-1
       |  +--rw metric?              isis:wide-metric
       |  +--rw flags
       |  |  +--rw whole-lan?           boolean
       |  |  +--rw allow-unreachable?   boolean
       |  +--rw exclude-te-metric?   boolean
       +--rw level-2
          +--rw metric?              isis:wide-metric
          +--rw flags
          |  +--rw whole-lan?           boolean
          |  +--rw allow-unreachable?   boolean
          +--rw exclude-te-metric?   boolean
  augment /rt:routing/rt:control-plane-protocols
            /rt:control-plane-protocol/isis:isis/isis:interfaces
            /isis:interface/isis:adjacencies/isis:adjacency:
    +--ro reverse-metric
       +--ro metric?      isis:wide-metric
       +--ro flags
       |  +--ro whole-lan?           boolean
       |  +--ro allow-unreachable?   boolean
       +--ro te-metric?   uint32
]]></artwork>
]]></sourcecode>

</section>

<section title="YANG Module"> numbered="true" toc="default">
<name>YANG Module</name>
<t>The following is the YANG module for managing the IS-IS reverse
metric functionality defined in <xref target="RFC8500"/>. It imports modules from the
following RFCs:  <xref target="RFC8349"/>, target="RFC8349"/> and <xref target="I-D.ietf-isis-yang-isis-cfg"/>.</t> target="RFC9130"/>.</t>

<t>This YANG module uses the same "Per-Level" per-level hierarchical configuration
structure as is that defined in the augmented base module.</t>

<sourcecode><![CDATA[
<CODE BEGINS>
<!-- [rfced] Section 2.2: FYI, we have updated the formatting of the YANG module per the formatting option of pyang. Please let us know of any concerns. -->
<sourcecode name="" type="yang" markers="true"><![CDATA[
file "ietf-isis-reverse-metric@2022-01-01.yang" "ietf-isis-reverse-metric@2022-02-03.yang"
module ietf-isis-reverse-metric {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric";
  prefix isis-rmetric;

  import ietf-routing {
    prefix rt;
    reference
      "RFC8349:
      "RFC 8349: A YANG Data Model for Routing Management
                 (NMDA Version)";
  }
  import ietf-isis {
    prefix isis;
    reference
      "draft-ietf-isis-yang-isis-cfg-42:
      "RFC 9130: YANG Data Model for the IS-IS Protocol";
  }

  organization
    "IETF LSR Working Group (LSR)";

  contact
    "WG Web:  <https://datatracker.ietf.org/wg/lsr/>
     WG List: <mailto:lsr@ietf.org>

     Author:  Christian Hopps
              <mailto:chopps@chopps.org>";

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

  description
    "This module defines the configuration and operational state
     for managing the IS-IS reverse metric functionality [RFC8500].
     (RFC 8500).

     Copyright (c) 2022 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject to
     the license terms contained in, the Simplified 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>); 9194; see the
     RFC itself for full legal notices.";
  reference
    "RFC 8500: IS-IS Routing with Reverse Metric";

  revision 2022-01-01 2022-02-03 {
    description
      "Initial Revision"; revision.";
    reference
      "RFC XXXX: 9194: A YANG Module for IS-IS Reverse Metric";
  }

  grouping reverse-metric-data {
    description
      "IS-IS reverse metric data.";
    leaf metric {
      type isis:wide-metric;
      description
        "The reverse metric value.";
      reference "RFC8500,
        "RFC 8500: IS-IS Routing with Reverse Metric, Section 2";
    }
    container flags {
      description
        "The reverse metric flag values.";
      leaf whole-lan {
        type boolean;
        description
          "The 'whole 'Whole LAN' or W-bit. bit (W bit) (RFC 8500).  If true true, then
           a DIS Designated Intermediate System (DIS) processing this
           reverse metric will add the metric value to all the
           nodes it advertises in the pseudo-node LSP pseudonode Link State
           Protocol Data Unit (LSP) for this interface.
           Otherwise, it will only increment the metric for the
           advertising node in the pseudo-node pseudonode LSP for this
           interface.";
        reference "RFC8500,
          "RFC 8500: IS-IS Routing with Reverse Metric,
                     Section 2";
      }
      leaf allow-unreachable {
        type boolean;
        description
          "The 'allow-unreachable' or U-bit. 'Unreachable' bit (U bit) (RFC 8500).  If true true, it
           allows the neighbor to increment the overall metric up
           to 2^24-1 rather than the lesser maximum of 2^24-2.
           If the metric is then set by the neighbor to 2^24-1,
           it will cause traffic to stop using, rather than avoid
           using, the interface.";
        reference "RFC8500,
          "RFC 8500: IS-IS Routing with Reverse Metric,
                     Section 2";
      }
    }
  }

  grouping reverse-metric-if-config-data {
    description
      "IS-IS reverse metric config data.";
    uses reverse-metric-data;
    leaf exclude-te-metric {
      type boolean;
      default false; "false";
      description
        "If true and there is a TE metric defined for this
         interface
         interface, then do not send the TE metric Traffic Engineering
         Metric sub-TLV in the
         reverse metric Reverse Metric TLV.";

      reference "RFC8500,
        "RFC 8500: IS-IS Routing with Reverse Metric, Section 2";
    }
  }

  grouping tlv16-reverse-metric {
    description
      "IS-IS reverse metric Reverse Metric TLV data.";
    uses reverse-metric-data;
    leaf te-metric {
      type uint32;
      description
        "The TE metric value from the sub-TLV sub-TLV, if present.";
      reference "RFC8500,
        "RFC 8500: IS-IS Routing with Reverse Metric, Section 2";
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    +"rt:control-plane-protocol/"
    +"isis:isis"
        + "rt:control-plane-protocol/"
        + "isis:isis" {
    when "derived-from-or-self(../rt:type, 'isis:isis')" {
      description
        "This augment is only valid when the routing protocol
         instance type is 'isis'.";
    }

    description
      "The reverse metric configuration for an IS-IS instance.";

    container reverse-metric {
      description
        "Global reverse metric configuration.";
      leaf enable-receive {
        type boolean;
        default false; "false";
        description
          "Enable
          "Enables handling of reverse metric announcements from
           neighbors.  By default, reverse metric handling is
           disabled and must be explicitly enabled through this
           configuration.";
      }
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    +"rt:control-plane-protocol/"
    +"isis:isis/isis:interfaces/isis:interface"
        + "rt:control-plane-protocol/"
        + "isis:isis/isis:interfaces/isis:interface" {
    when "derived-from-or-self(../../../rt:type, 'isis:isis')" {
      description
        "This augment is only valid when the routing protocol
         instance type is 'isis'.";
    }

    description
      "The reverse metric configuration for an interface.";

    container reverse-metric {
      description
        "Announce
        "Announces a reverse metric to neighbors.  The
         configuration is hierarchical and follows the same
         behavior as that defined for 'Per-Level' per-level values in the
         augmented base module.

         Reverse metric operation is enabled by the configuration
         of a reverse-metric 'reverse-metric' metric value at either at the top
         level or under a level-specific container node.  If a reverse-metric
         'reverse-metric' metric value is only specified under a
         level-specific container node node, then operation is only
         enabled at the specified level.

         As the reverse metric is advertised in IIH PDUs, level
         specific IS-IS Hello
         Protocol Data Units (IIH PDUs), level-specific
         configuration is only available for broadcast interface types";
         types.";
      uses reverse-metric-if-config-data {
        refine "flags/whole-lan" {
          default false; "false";
        }
        refine "flags/allow-unreachable" {
          default false; "false";
        }
      }
      container level-1 {
        when '../../isis:interface-type = "broadcast"';
        description
          "Announce
          "Announces a reverse metric to level-1 neighbors.";
        uses reverse-metric-if-config-data;
      }
      container level-2 {
        when '../../isis:interface-type = "broadcast"';
        description
          "Announce
          "Announces a reverse metric to level-2 neighbors.";
        uses reverse-metric-if-config-data;
      }
    }
  }
  augment "/rt:routing/rt:control-plane-protocols/"
    +"rt:control-plane-protocol/"
    +"isis:isis/isis:interfaces/isis:interface/"
    +"isis:adjacencies/isis:adjacency"
        + "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 augment is only valid when the routing protocol
         instance type is 'isis'"; 'isis'.";
    }

    description
      "The reverse metric state advertised by an adjacency.";
    container reverse-metric {
      description
        "IS-IS reverse metric Reverse Metric TLV data.";
      uses tlv16-reverse-metric;
    }
  }
}
<CODE ENDS>
]]></sourcecode>

<!-- [rfced] Section 2.2:

a) For ease of the reader, we defined "DIS" and "LSP" per
RFC 8500.  Please let us know any concerns.

Original:
 description
     "The 'whole LAN' or W-bit. If true then a DIS processing
     this reverse metric will add the metric value to all the
     nodes it advertises in the pseudo-node LSP for this
     interface.

Currently:
 description
   "The 'Whole LAN' bit (W bit) (RFC 8500).  If true, then
    a Designated Intermediate System (DIS) processing this
    reverse metric will add the metric value to all the
    nodes it advertises in the pseudonode Link State
    Protocol Data Unit (LSP) for this interface.

b) For ease of the reader, we expanded "IIH" as "IS-IS Hello" per
RFC 8500 and also expanded "PDUs" as "Protocol Data Units".
If these expansions are incorrect, please provide the correct
definitions.

Original:
 As the reverse metric is advertised in IIH PDUs, level
 specific configuration is only available for broadcast
 interface types";

Currently:
 As the reverse metric is advertised in IS-IS Hello
 Protocol Data Units (IIH PDUs), level-specific
 configuration is only available for broadcast interface
 types."; -->

</section>

</section>

<section title="IANA Considerations"> numbered="true" toc="default">
<name>IANA Considerations</name>
<section title="Updates numbered="true" toc="default">
<name>Updates to the IETF XML Registry"> Registry</name>
<t>This document registers a URI in the "IETF XML Registry" <xref target="RFC3688"/>.
Following the format in <xref target="RFC3688"/>, the following registration has been
made:</t>

<dl>
<dt>URI</dt><dd><t>urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric</t></dd>
<!-- [rfced] FYI, after the document approval is received, we will ask IANA to make the following update to <https://www.iana.org/assignments/xml-registry/ns/yang/ietf-isis-reverse-metric.txt>:

OLD:
URI urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric

Registrant Contact The IESG.

XML N/A; the requested URI is an XML namespace.

NEW (add colons):
URI: urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric

Registrant Contact: The IESG.

XML: N/A; the requested URI is an XML namespace.
-->
<dl spacing="compact">
<dt>URI:</dt><dd>urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric</dd>
<dt>Registrant Contact</dt><dd><t>The IESG.</t></dd>
<dt>XML</dt><dd><t>N/A; Contact:</dt><dd>The IESG.</dd>
<dt>XML:</dt><dd>N/A; the requested URI is an XML namespace.</t></dd> namespace.</dd>
</dl>

</section>

<section title="Updates numbered="true" toc="default">
<name>Updates to the YANG Module Names Registry"> Registry</name>
<t>This document registers one YANG module in the "YANG Module Names"
registry <xref target="RFC6020"/>. Following the format in <xref target="RFC6020"/>, the following
registration has been made:</t>

<dl>
<dt>name</dt><dd><t>ietf-isis-reverse-metric</t></dd>
<dt>namespace</dt><dd><t>urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric</t></dd>
<dt>prefix</dt><dd><t>isis-rmetric</t></dd>
<dt>reference</dt><dd><t>RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.)</t></dd>

<dl spacing="compact">
<dt>Name:</dt><dd>ietf-isis-reverse-metric</dd>
<dt>Maintained by IANA?</dt><dd>N</dd>
<dt>Namespace:</dt><dd>urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric</dd>
<dt>Prefix:</dt><dd>isis-rmetric</dd>
<dt>Reference:</dt><dd>RFC 9194</dd>
</dl>

</section>

</section>

<section title="Security Considerations"> numbered="true" toc="default">
<name>Security Considerations</name>
<!-- Begin YANG security DNE text Para. 1 -->
<t>The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such
as NETCONF <xref target="RFC6241"/> or RESTCONF <xref target="RFC8040"/>.
The lowest NETCONF layer is the secure transport layer, and the
mandatory-to-implement secure transport is Secure Shell (SSH)
<xref target="RFC6242"/>. The lowest RESTCONF layer is HTTPS, and the
mandatory-to-implement secure transport is TLS <xref target="RFC8446"/>.</t>
<!-- End YANG security DNE text Para. 1 -->

<!-- Begin YANG security DNE text Para. 2 (fixed per boilerplate) -->
<t>The NETCONF access control model 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>
<!-- End YANG security DNE text Para. 2 -->

<t>The YANG module defined in this document can enable, disable disable, and
modify the behavior of metrics used by routing. For the security
implications regarding these types of changes changes, consult <xref target="RFC8500"/> --
which defines the functionality -- as well as <xref target="I-D.ietf-isis-yang-isis-cfg"/>.</t> target="RFC9130"/>.</t>

<!-- Begin YANG security DNE text Para. 3 (fixed per boilerplate;
   contains an additional sentence; last sentence matches presentation of the information rather than boilerplate) -->
<t>There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., "config true", config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative effect
on network operations.  These YANG nodes correspond directly to the
RFC 8500
functionality provided in RFC 8500, and the security considerations of the
functionality are described in RFC 8500.</t>

<t>These 8500.
These are the subtrees and data nodes:</t>

<artwork><![CDATA[
<!-- End YANG security DNE text Para. 3 -->
<artwork type="ascii-art"><![CDATA[
Under "/rt:routing/rt:control-plane-protocols/" +
      "rt:control-plane-protocol/isis:isis"

  - /isis-rmetric:reverse-metric/isis-rmetric:enable-receive
]]></artwork>

<artwork><![CDATA[

<artwork type="ascii-art"><![CDATA[
Under "/rt:routing/rt:control-plane-protocols/" +
      "rt:control-plane-protocol/isis:isis/" +
      "isis:interfaces/isis:interface/" +
      "isis-rmetric:reverse-metric"

  - /isis-rmetric:metric
  - /isis-rmetric:flags/isis-rmetric:whole-lan
  - /isis-rmetric:flags/isis-rmetric:allow-unreachable
  - /isis-rmetric:exclude-te-metric
]]></artwork>

<artwork><![CDATA[

<artwork type="ascii-art"><![CDATA[
Under "/rt:routing/rt:control-plane-protocols/" +
      "rt:control-plane-protocol/isis:isis/" +
      "isis:interfaces/isis:interface/" +
      "isis-rmetric:reverse-metric/" +
      "isis-rmetric:level-1/"

  - /isis-rmetric:metric
  - /isis-rmetric:flags/isis-rmetric:whole-lan
  - /isis-rmetric:flags/isis-rmetric:allow-unreachable
  - /isis-rmetric:exclude-te-metric
]]></artwork>

<artwork><![CDATA[

<artwork type="ascii-art"><![CDATA[
Under "/rt:routing/rt:control-plane-protocols/" +
      "rt:control-plane-protocol/isis:isis/" +
      "isis:interfaces/isis:interface/" +
      "isis-rmetric:reverse-metric/" +
      "isis-rmetric:level-2/"

  - /isis-rmetric:metric
  - /isis-rmetric:flags/isis-rmetric:whole-lan
  - /isis-rmetric:flags/isis-rmetric:allow-unreachable
  - /isis-rmetric:exclude-te-metric
]]></artwork>

<!-- Begin YANG security DNE text Para. 4 (fixed per boilerplate;
   contains an additional sentence; last sentence matches presentation of the information rather than boilerplate) -->
<t>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. These YANG nodes correspond
directly to the RFC 8500 functionality provided in RFC 8500, and the security
considerations of the functionality are described in RFC 8500.
These are the subtrees and data nodes:</t>

<artwork><![CDATA[
<!-- End YANG security DNE text Para. 4 -->

<artwork type="ascii-art"><![CDATA[
Under "/rt:routing/rt:control-plane-protocols/" +
      "rt:control-plane-protocol/isis:isis/" +
      "isis:interfaces/isis:interface/" +
      "isis:adjacencies/isis:adjacency/" +
      "isis-rmetric:reverse-metric"

  - /isis-rmetric:metric
  - /isis-rmetric:flags/isis-rmetric:whole-lan
  - /isis-rmetric:flags/isis-rmetric:allow-unreachable
  - /isis-rmetric:te-metric
]]></artwork>
</section>

</middle>
<back>
<references title="Normative References">
<references>
<name>Normative References</name>
  <reference anchor="ISO10589"> anchor="ISO-10589" target="https://www.iso.org/standard/30932.html">
    <front>
      <title>Intermediate System to Intermediate System intra-domain intra-
         domain routeing information exchange protocol for use in
         conjunction with the protocol for providing the
         connectionless-mode network service (ISO 8473)</title>
<author><organization>International Organization for Standardization</organization></author>
      <author><organization>ISO</organization></author>
      <date year="2002"/>
</front><refcontent>ISO Standard 10589:2002</refcontent>
</reference>

<reference  anchor='RFC3688' target='https://www.rfc-editor.org/info/rfc3688'>
<front>
<title>The IETF XML Registry</title>
<author initials='M.' surname='Mealling' fullname='M. Mealling'><organization /></author>
<date year='2004' month='January' />
<abstract><t>This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.</t></abstract>
</front>
<seriesInfo name='BCP' value='81'/>
<seriesInfo name='RFC' value='3688'/>
<seriesInfo name='DOI' value='10.17487/RFC3688'/>
</reference>

<reference  anchor='RFC6020' target='https://www.rfc-editor.org/info/rfc6020'>
<front>
<title>YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund' role='editor'><organization /></author>
<date year='2010' month='October' />
<abstract><t>YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6020'/>
<seriesInfo name='DOI' value='10.17487/RFC6020'/>
</reference>

<reference  anchor='RFC8341' target='https://www.rfc-editor.org/info/rfc8341'>
<front>
<title>Network Configuration Access Control Model</title>
<author initials='A.' surname='Bierman' fullname='A. Bierman'><organization /></author>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author>
<date year='2018' month='March' />
<abstract><t>The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability.  There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.  This document defines such an access control model.</t><t>This document obsoletes RFC 6536.</t></abstract>
</front>
<seriesInfo name='STD' value='91'/>
<seriesInfo name='RFC' value='8341'/>
<seriesInfo name='DOI' value='10.17487/RFC8341'/>
</reference>

<reference  anchor='RFC8342' target='https://www.rfc-editor.org/info/rfc8342'>
<front>
<title>Network Management Datastore Architecture (NMDA)</title>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author>
<author initials='J.' surname='Schoenwaelder' fullname='J. Schoenwaelder'><organization /></author>
<author initials='P.' surname='Shafer' fullname='P. Shafer'><organization /></author>
<author initials='K.' surname='Watsen' fullname='K. Watsen'><organization /></author>
<author initials='R.' surname='Wilton' fullname='R. Wilton'><organization /></author>
<date year='2018' month='March' />
<abstract><t>Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model.  This document updates RFC 7950.</t></abstract>
    </front>
<seriesInfo name='RFC' value='8342'/>
<seriesInfo name='DOI' value='10.17487/RFC8342'/>
    <refcontent>International Standard 10589: 2002, Second Edition</refcontent>
  </reference>

<reference  anchor='RFC8349' target='https://www.rfc-editor.org/info/rfc8349'>
<front>
<title>A YANG Data Model for Routing Management (NMDA Version)</title>
<author initials='L.' surname='Lhotka' fullname='L. Lhotka'><organization /></author>
<author initials='A.' surname='Lindem' fullname='A. Lindem'><organization /></author>
<author initials='Y.' surname='Qu' fullname='Y. Qu'><organization /></author>
<date year='2018' month='March' />
<abstract><t>This document specifies three YANG modules

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6242.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8040.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8341.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8349.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8446.xml"/>

<!-- [rfced] Normative References:

Per <https://trac.ietf.org/trac/ops/wiki/yang-security-guidelines>
'(Note: [RFC 8446], [RFC6241], [RFC6242], [RFC8341], and one submodule. Together, they form the core routing data model that serves as a framework for configuring and managing a routing subsystem.  It is expected that these modules will [RFC8040]
must be augmented by additional YANG modules defining data models for control-plane protocols, route filters, and other functions.  The core routing data model provides common building blocks for such extensions -- routes, Routing Information Bases (RIBs), and control-plane protocols.</t><t>The YANG modules in this document conform to "normative references".)', we moved the Network Management Datastore Architecture (NMDA).  This document obsoletes RFC 8022.</t></abstract>
</front>
<seriesInfo name='RFC' value='8349'/>
<seriesInfo name='DOI' value='10.17487/RFC8349'/>
</reference>

<reference  anchor='RFC8500' target='https://www.rfc-editor.org/info/rfc8500'>
<front>
<title>IS-IS Routing with Reverse Metric</title>
<author initials='N.' surname='Shen' fullname='N. Shen'><organization /></author>
<author initials='S.' surname='Amante' fullname='S. Amante'><organization /></author>
<author initials='M.' surname='Abrahamsson' fullname='M. Abrahamsson'><organization /></author>
<date year='2019' month='February' />
<abstract><t>This document describes a mechanism to allow IS-IS routing to quickly listings for
RFCs 6241, 6242, 8040, 8341, and accurately shift traffic away 8446 from either a point-to-point or multi-access LAN interface during network maintenance or other operational events.  This is accomplished by signaling adjacent IS-IS neighbors with a higher reverse metric, i.e., the metric towards Informative
References section to the signaling IS-IS router.</t></abstract>
</front>
<seriesInfo name='RFC' value='8500'/>
<seriesInfo name='DOI' value='10.17487/RFC8500'/>
</reference> Normative References section.  Please
let us know any concerns. -->

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8500.xml"/>

<!-- draft-ietf-isis-yang-isis-cfg (RFC-to-be 9130 / AUTH48) -->
<reference anchor="I-D.ietf-isis-yang-isis-cfg"> anchor='RFC9130' target="https://www.rfc-editor.org/info/rfc9130">
<front>
<title>YANG Data Model for the IS-IS Protocol</title>
<author fullname="Stephane Litkowski">
	 <organization>Cisco Systems</organization>
      </author>
      <author fullname="Derek Yeung">
	 <organization>Arrcus, Inc</organization>
      </author>
      <author fullname="Acee Lindem">
	 <organization>Cisco Systems</organization>
      </author>
      <author fullname="Jeffrey Zhang">
	 <organization>Juniper Networks</organization> initials='S' surname='Litkowski' fullname='Stephane Litkowski' role="editor">
    <organization />
</author>
<author fullname="Ladislav Lhotka">
	 <organization>CZ.NIC</organization>
      </author>
      <date month="October" day="15" year="2019" />
      <abstract>
	 <t>   This document defines a YANG data model that can be used to configure
   and manage the IS-IS protocol on network elements.

	 </t>
      </abstract>
   </front>
   <seriesInfo name="Internet-Draft" value="draft-ietf-isis-yang-isis-cfg-42" initials='D' surname='Yeung' fullname='Derek Yeung'>
    <organization />
   <format type="TXT" target="https://www.ietf.org/archive/id/draft-ietf-isis-yang-isis-cfg-42.txt" />
</reference>
</references>

<references title="Informative References">

<reference  anchor='RFC6241' target='https://www.rfc-editor.org/info/rfc6241'>
<front>
<title>Network Configuration Protocol (NETCONF)</title>
<author initials='R.' surname='Enns' fullname='R. Enns' role='editor'><organization /></author>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund' role='editor'><organization /></author>
<author initials='J.' surname='Schoenwaelder' fullname='J. Schoenwaelder' role='editor'><organization /></author>
</author>
<author initials='A.' surname='Bierman' fullname='A. Bierman' role='editor'><organization /></author>
<date year='2011' month='June' initials='A' surname='Lindem' fullname='Acee Lindem'>
    <organization />
<abstract><t>The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices.  It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages.  The NETCONF protocol operations are realized as remote procedure calls (RPCs).  This document obsoletes RFC 4741.  [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6241'/>
<seriesInfo name='DOI' value='10.17487/RFC6241'/>
</reference>

<reference  anchor='RFC6242' target='https://www.rfc-editor.org/info/rfc6242'>
<front>
<title>Using the NETCONF Protocol over Secure Shell (SSH)</title>
</author>
<author initials='M.' surname='Wasserman' fullname='M. Wasserman'><organization /></author>
<date year='2011' month='June' initials='J' surname='Zhang' fullname='Jeffrey Zhang'>
    <organization />
<abstract><t>This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem.  This document obsoletes RFC 4742.  [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6242'/>
<seriesInfo name='DOI' value='10.17487/RFC6242'/>
</reference>

<reference  anchor='RFC7951' target='https://www.rfc-editor.org/info/rfc7951'>
<front>
<title>JSON Encoding of Data Modeled with YANG</title>
</author>
<author initials='L.' initials='L' surname='Lhotka' fullname='L. Lhotka'><organization /></author>
<date year='2016' month='August' fullname='Ladislav Lhotka'>
    <organization />
<abstract><t>This document defines encoding rules for representing configuration data, state data, parameters of Remote Procedure Call (RPC) operations or actions, and notifications defined using YANG as JavaScript Object Notation (JSON) text.</t></abstract>
</front>
<seriesInfo name='RFC' value='7951'/>
<seriesInfo name='DOI' value='10.17487/RFC7951'/>
</reference>

<reference  anchor='RFC8040' target='https://www.rfc-editor.org/info/rfc8040'>
<front>
<title>RESTCONF Protocol</title>
<author initials='A.' surname='Bierman' fullname='A. Bierman'><organization /></author>
<author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author>
<author initials='K.' surname='Watsen' fullname='K. Watsen'><organization /></author>
</author>
<date year='2017' month='January' year='2022' />
<abstract><t>This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).</t></abstract>
</front>
<seriesInfo name='RFC' value='8040'/> name="RFC" value="9130"/>
<seriesInfo name='DOI' value='10.17487/RFC8040'/> name="DOI" value="10.17487/RFC9130"/>
</reference>

    <reference  anchor='RFC8340' target='https://www.rfc-editor.org/info/rfc8340'> anchor="W3C.REC-xml-20081126" target="https://www.w3.org/TR/2008/REC-xml-20081126" quoteTitle="true" derivedAnchor="W3C.REC-xml-20081126">
          <front>
<title>YANG Tree Diagrams</title>
            <title>Extensible Markup Language (XML) 1.0 (Fifth Edition)</title>
            <author initials="T." surname="Bray" fullname="Tim Bray">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials='M.' surname='Bjorklund' fullname='M. Bjorklund'><organization /></author> initials="J." surname="Paoli" fullname="Jean Paoli">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials='L.' surname='Berger' fullname='L. Berger' role='editor'><organization /></author>
<date year='2018' month='March' />
<abstract><t>This document captures the current syntax used in YANG module tree diagrams.  The purpose of this document is to provide a single location for this definition.  This syntax may be updated from time to time based on the evolution of the YANG language.</t></abstract>
</front>
<seriesInfo name='BCP' value='215'/>
<seriesInfo name='RFC' value='8340'/>
<seriesInfo name='DOI' value='10.17487/RFC8340'/>
</reference>

<reference  anchor='RFC8446' target='https://www.rfc-editor.org/info/rfc8446'>
<front>
<title>The Transport Layer Security (TLS) Protocol Version 1.3</title> initials="M." surname="Sperberg-McQueen" fullname="Michael Sperberg-McQueen">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials="E." surname="Maler" fullname="Eve Maler">
              <organization showOnFrontPage="true"/>
            </author>
            <author initials='E.' surname='Rescorla' fullname='E. Rescorla'><organization /></author> initials="F." surname="Yergeau" fullname="Francois Yergeau">
              <organization showOnFrontPage="true"/>
            </author>
            <date year='2018' month='August' />
<abstract><t>This document specifies version 1.3 of the Transport Layer Security (TLS) protocol.  TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery.</t><t>This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961.  This document also specifies new requirements for TLS 1.2 implementations.</t></abstract> month="November" year="2008"/>
          </front>
<seriesInfo name='RFC' value='8446'/>
<seriesInfo name='DOI' value='10.17487/RFC8446'/>
          <refcontent>World Wide Web Consortium Recommendation REC-xml-20081126</refcontent>
        </reference>
</references>

<references>
<name>Informative References</name>

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7951.xml"/>
</references>

<section title="Examples"> numbered="true" toc="default">
<name>Examples</name>
<section title="Enablement numbered="true" toc="default">
<name>Enablement Example using Using XML YANG Instance Data"> Data</name>
<t>Below is an example of XML <xref target="W3C.REC-xml-20081126"/> YANG instance data <xref target="RFC8342"/> to enable reverse metric processing.</t>

<figure><name>Example processing.

<!-- [rfced] Appendix A.1:  Christian and [AD]:  Because this
document contains XML, per
<https://www.ietf.org/about/groups/iesg/statements/formal-languages-use/>,
we added a Normative Reference for [W3C.REC-xml-20081126].
Please let us know any concerns.

Original:
 Below is an example of XML YANG instance data [RFC8342] to enable
 reverse metric processing.

Currently:
 Below is an example of XML [W3C.REC-xml-20081126] YANG instance data
 [RFC8342] to enable reverse metric processing.</name><sourcecode><![CDATA[ processing.
...
 [W3C.REC-xml-20081126]
            Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
            F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
            Edition)", World Wide Web Consortium Recommendation REC-
            xml-20081126, November 2008,
            <https://www.w3.org/TR/2008/REC-xml-20081126>. -->

</t>

<figure>
<name>Example XML Data to Enable Reverse Metric Processing</name>
<sourcecode type="xml"><![CDATA[
<rt:routing
    xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
    xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis"
    xmlns:isis-rmetric=
    "urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric">
  <rt:control-plane-protocols>
    <rt:control-plane-protocol>
      <rt:type>isis:isis</rt:type>
      <rt:name>default</rt:name>
      <isis:isis>
        <isis:area-address>00</isis:area-address>
        <isis-rmetric:reverse-metric>
     <isis-rmetric:enable-receive>true</isis-rmetric:enable-receive>
        </isis-rmetric:reverse-metric>
      </isis:isis>
    </rt:control-plane-protocol>
  </rt:control-plane-protocols>
</rt:routing>
]]></sourcecode></figure>

</section>

<section title="Usage numbered="true" toc="default">
<name>Usage Example using Using XML YANG Instance Data"> Data</name>
<t>Below is an example of XML YANG instance data <xref target="RFC8342"/> for the
ietf-isis-reverse-metric
"ietf-isis-reverse-metric" module.</t>

<figure><name>Example

<figure>
<name>Example XML data Data for ietf-isis-reverse-metric module.</name><sourcecode><![CDATA[ the &quot;ietf-isis-reverse-metric&quot; Module</name>
<sourcecode type="xml"><![CDATA[
<if:interfaces
    xmlns:if="urn:ietf:params:xml:ns:yang:ietf-interfaces"
    xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
  <if:interface>
    <if:name>eth0</if:name>
    <if:type>ianaift:ethernetCsmacd</if:type>
  </if:interface>
</if:interfaces>
<rt:routing
    xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
    xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis"
    xmlns:isis-rmetric=
    "urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric">
  <rt:control-plane-protocols>
    <rt:control-plane-protocol>
      <rt:type>isis:isis</rt:type>
      <rt:name>default</rt:name>
      <isis:isis>
        <isis:area-address>00</isis:area-address>
        <isis:interfaces>
          <isis:interface>
            <isis:name>eth0</isis:name>
            <isis-rmetric:reverse-metric>
              <isis-rmetric:metric>
                65535
              </isis-rmetric:metric>
            </isis-rmetric:reverse-metric>
          </isis:interface>
        </isis:interfaces>
      </isis:isis>
    </rt:control-plane-protocol>
  </rt:control-plane-protocols>
</rt:routing>
]]></sourcecode></figure>

</section>

<section title="Usage numbered="true" toc="default">
<name>Usage Example using Using JSON YANG Instance Data"> Data</name>
<t>Below is an example of JSON YANG instance data <xref target="RFC7951"/> for the
ietf-isis-reverse-metric
"ietf-isis-reverse-metric" module.</t>

<figure><name>Example

<figure>
<name>Example JSON data Data for level-1 only reverse metric.</name><sourcecode><![CDATA[ the Level-1-Only Reverse Metric</name>
<sourcecode type="json"><![CDATA[
{
  "ietf-interfaces:interfaces": {
    "interface": [
      {
        "name": "eth0",
        "type": "iana-if-type:ethernetCsmacd"
      }
    ]
  },
  "ietf-routing:routing": {
    "control-plane-protocols": {
      "control-plane-protocol": [
        {
          "type": "ietf-isis:isis",
          "name": "default",
          "ietf-isis:isis": {
            "area-address": [
              "00"
            ],
            "interfaces": {
              "interface": [
                {
                  "name": "eth0",
                  "ietf-isis-reverse-metric:reverse-metric": {
                    "level-1": {
                      "metric": 65535,
                      "exclude-te-metric": true
                    }
                  }
                }
              ]
            }
          }
        }
      ]
    }
  }
}
]]></sourcecode></figure>

</section>

</section>

<!-- [rfced] Please review the "Inclusive Language" portion of the
online Style Guide at
<https://www.rfc-editor.org/styleguide/part2/#inclusive_language>,
and let us know if any changes are needed. -->

  </back>
</rfc>