Network Working Group                                           C. Hopps
Internet-Draft                                   LabN Consulting, L.L.C.
Intended status: Standards Track                           31 March 2019
Expires: 2 October 2019


         YANG Data Model for the IS-IS Reverse Metric Extension
              draft-hopps-lsr-yang-isis-reverse-metric-00

Abstract

   This document defines a YANG module for managing the reverse metric
   extension to the the intermediate system to intermediate system
   routeing protocol.

Status of This Memo

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

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   This Internet-Draft will expire on 2 October 2019.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1.  Introduction
   2.  YANG Management
       2.1.  YANG Tree
       2.2.  YANG Module
   3.  IANA Considerations
       3.1.  Updates to the IETF XML Registry
       3.2.  Updates to the YANG Module Names Registry
   4.  Security Considerations
   5.  Normative References
   6.  Informative References
   Author's Address

1.  Introduction

   This document defines a YANG module for managing the reverse metric
   extension to the intermediate system to intermediate system routeing
   protocol (IS-IS) [RFC8500], [ISO10589].  Please refer to [RFC8500]
   for the description and definition of the functionality managed by
   this module.

   The YANG data model described in this document conforms to the
   Network Management Datastore Architecture defined in [RFC8342].

2.  YANG Management

2.1.  YANG Tree

   The following is the YANG tree diagram ([RFC8340]) for the IS-IS
   reverse metric extension additions.

   module: ietf-isis-reverse-metric
     augment /rt:routing/rt:control-plane-protocols
               /rt:control-plane-protocol/isis:isis/isis:interfaces
               /isis:interface:
       +--rw reverse-metric
          +--rw reverse-metric
          |  +--rw metric?   isis:wide-metric
          |  +--rw flags?    bits
          +--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?    bits
       +--ro te-metric?        uint32

2.2.  YANG Module

   The following is the YANG module for managing the IS-IS reverse
   metric functionality defined in [RFC8500].

   <CODE BEGINS> file "ietf-isis-reverse-metric@2019-03-31.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-isis { prefix isis; }
     import ietf-routing { prefix "rt"; }

     organization
       "IETF NETMOD Working Group (NETMOD)";
     contact
       "WG Web:  <https://tools.ietf.org/wg/netmod/>
        WG List: <mailto:netmod@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].

        Copyright (c) 2019 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 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://tools.ietf.org/html/rfcXXXX); see the RFC itself for
        full legal notices.";

     revision 2019-03-31 {
       description "Initial Revision";
       reference "RFC XXXX: YANG IS-IS Reverse Metric";
     }

     grouping reverse-metric-data {
       description "IS-IS reverse metric data.";
       container reverse-metric {
         description "IS-IS reverse metric data.";
         leaf metric {
           type isis:wide-metric;
           description "The reverse metric value.";
         }
         leaf flags {
           type bits {
             bit whole-lan {
               position 0;
               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. Otherwise it will
                  only increment the metric for the advertising node in
                  the pseudo-node LSP for this interface.";
             }
             bit allow-unreachable {
               position 1;
               description
                 "The 'allow-unreachable' or U-bit. If true it allows
                  the neighbor to increment the overall metric up to
                  2^24-1 rather than the lesser maximum of 2^24-2, and
                  if done will cause traffic to stop using rather than
                  avoid using the interface.";
             }
           }
           description "The reverse metric flag values.";
         }
       }
     }

     grouping tlv16-reverse-metric {
       description "IS-IS reverse metric TLV data.";
       uses reverse-metric-data;
       leaf te-metric {
         type uint32;
         description "The TE metric value from the sub-TLV if present.";
       }
     }

     augment "/rt:routing/rt:control-plane-protocols/"
       +"rt:control-plane-protocol/"
       +"isis:isis/isis:interfaces/isis:interface" {
       when "rt:type = 'isis:isis'" {
         description
           "This augment is only valid when routing protocol instance
            type is 'isis'.";
       }

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

       container reverse-metric {
         description "Announce a reverse metric to neighbors.";
         uses reverse-metric-data;
         leaf exclude-te-metric {
           type boolean;
           default false;
           description
             "If true and there is a TE metric defined for this
              interface then do not send the TE metric sub-TLV in the
              reverse metric TLV.";
         }
       }
     }
     augment "/rt:routing/rt:control-plane-protocols/"
       +"rt:control-plane-protocol/"
       +"isis:isis/isis:interfaces/isis:interface/"
       +"isis:adjacencies/isis:adjacency" {
       when "rt:type = 'isis:isis'" {
         description
           "This augment is only valid when routing protocol instance
            type is 'isis'";
       }

       description
         "The reverse metric state advertised by a neighbor.";
       uses tlv16-reverse-metric;
     }
   }
   <CODE ENDS>

3.  IANA Considerations

3.1.  Updates to the IETF XML Registry

   This document registers a URI in the "IETF XML Registry" [RFC3688].
   Following the format in [RFC3688], the following registration has
   been made:

   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.

3.2.  Updates to the YANG Module Names Registry

   This document registers one YANG module in the "YANG Module Names"
   registry [RFC6020].  Following the format in [RFC6020], the following
   registration has been made:

   name       ietf-isis-reverse-metric

   namespace  urn:ietf:params:xml:ns:yang:ietf-isis-reverse-metric

   prefix     isis-rmetric

   reference  RFC XXXX (RFC Ed.: replace XXX with actual RFC number and
              remove this note.)

4.  Security Considerations

   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 [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

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

   The YANG module defined in this document can enable, disable and
   modify the behavior of metrics used by routing.  For the security
   implications regarding these types of changes consult the [RFC8500]
   which defines the functionality.

5.  Normative References

   [ISO10589] International Organization for Standardization,
              "Intermediate system to intermediate system intra-domain-
              routing routine information exchange protocol for use in
              conjunction with the protocol for providing the
              connectionless-mode Network Service (ISO 8473)",
              ISO Standard 10589, 1992.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8500]  Shen, N., Amante, S., and M. Abrahamsson, "IS-IS Routing
              with Reverse Metric", RFC 8500, DOI 10.17487/RFC8500,
              February 2019, <https://www.rfc-editor.org/info/rfc8500>.

6.  Informative References

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Author's Address

   Christian Hopps
   LabN Consulting, L.L.C.

   Email: chopps@chopps.org