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Versions: 00 01 02 03 04                                                
Network Working Group                                              Z. Hu
Internet-Draft                                                   X. Geng
Intended status: Standards Track                     Huawei Technologies
Expires: January 2, 2022                                         K. Raza
                                                     Cisco Systems, Inc.
                                                                   Y. Qu
                                                  Futurewei Technologies
                                                               A. Lindem
                                                           Cisco Systems
                                                            July 1, 2021


                     YANG Data Model for OSPF SRv6
                     draft-hu-lsr-ospf-srv6-yang-03

Abstract

   This document defines a YANG data model that can be used to configure
   and manage OSPFv3 SRv6 as defined in I-D.ietf-lsr-
   ospfv3-srv6-extensions.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

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

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

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

   This Internet-Draft will expire on January 2, 2022.








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Copyright Notice

   Copyright (c) 2021 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 and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text 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
   2.  Terminology and Notation  . . . . . . . . . . . . . . . . . .   3
     2.1.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   4
   3.  OSPFv3 SRv6 Configuration . . . . . . . . . . . . . . . . . .   4
     3.1.  SRv6 Activation . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Locator Setting . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  IP Fast Reroute . . . . . . . . . . . . . . . . . . . . .   5
     3.4.  Micro-loop Avoidance  . . . . . . . . . . . . . . . . . .   5
   4.  YANG Module and Tree  . . . . . . . . . . . . . . . . . . . .   5
     4.1.  OSPFv3 SRv6 Model Tree  . . . . . . . . . . . . . . . . .   5
     4.2.  OSPFv3 SRv6 YANG Module . . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  21
   6.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  22
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  22
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  22
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  23
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24

1.  Introduction

   YANG [RFC6020] [RFC7950] is a data definition language used to define
   the contents of a conceptual data store that allows networked devices
   to be managed using NETCONF [RFC6241].  YANG is proving relevant
   beyond its initial confines, as bindings to other interfaces (e.g.,
   ReST) and encodings other than XML (e.g., JSON) are being defined.
   Furthermore, YANG data models can be used as the basis for
   implementation of other interfaces, such as CLI and programmatic
   APIs.





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   This document defines a YANG data model that can be used to configure
   and manage OSPFv3 SRv6 and it is an augmentation to the OSPF YANG
   data model.

2.  Terminology and Notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The following terms are defined in [RFC8342]:

   o  client

   o  server

   o  configuration

   o  system state

   o  operational state

   o  intended configuration

   The following terms are defined in [RFC7950]:

   o  action

   o  augment

   o  container

   o  container with presence

   o  data model

   o  data node

   o  feature

   o  leaf

   o  list

   o  mandatory node




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   o  module

   o  schema tree

   o  RPC (Remote Procedure Call) operation

2.1.  Tree Diagrams

   Tree diagrams used in this document follow the notation defined in
   [RFC8340].

2.2.  Prefixes in Data Node Names

   In this document, names of data nodes, actions, and other data model
   objects are often used without a prefix, as long as it is clear from
   the context in which YANG module each name is defined.  Otherwise,
   names are prefixed using the standard prefix associated with the
   corresponding YANG module, as shown in Table 1.

   +------------+-----------------------------+-----------------------+
   | Prefix     |YANG Module                  |  Reference            |
   +------------+-----------------------------+-----------------------+
   |ospfv3-e-lsa| ietf-ospfv3-extended-lsa    | I-D.ietf-lsr-ospfv3   |
   |            |                             | -extended-lsa-yang    |
   |            |                             |                       |
   | ospf       | ietf-ospf                   | I-D.ietf-ospf-yang    |
   |            |                             |                       |
   | srv6       | ietf-srv6-base              | I-D.ietf-spring-srv6  |
   |            |                             |  -yang                |
   |            |                             |                       |
   | sr         | ietf-segment-routing        | [RFC9020]             |
   |            |                             |                       |
   | rt         | ietf-routing                | [RFC8349]             |
   |            |                             |                       |
   | yang       | ietf-yang-types             | [RFC6991]             |
   |            |                             |                       |
   | inet       | ietf-inet-types             | [RFC6991]             |
   +------------+-----------------------------+-----------------------+

             Table 1: Prefixes and Corresponding YANG Modules

3.  OSPFv3 SRv6 Configuration

   This document defines a model for OSPFv3 SRv6 feature.  It is an
   augmentation of the OSPF base model.

   The OSPFv3 SRv6 YANG module requires support of OSPF base model
   [I-D.ietf-ospf-yang] which defines basic OSPF configuration and state



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   and support of OSPFv3 Extended LSAs model
   [I-D.ietf-lsr-ospfv3-extended-lsa-yang].

3.1.  SRv6 Activation

   Activation of OSPFv3 SRv6 is done by setting the "enable" leaf to
   true.  This triggers advertisement of SRv6 extensions based on the
   configuration parameters that have been setup using the base SRv6
   module [I-D.ietf-spring-srv6-yang].

3.2.  Locator Setting

   The SRv6 base module [I-D.ietf-spring-srv6-yang] defines locators.
   When OSPFv6 SRv6 is enabled, the specified locators are used unless
   it is enabled to use the default locator.  The default locator can be
   set by using two leafs, i.e.,"default-locator" leaf, "locator-name"
   leaf.

3.3.  IP Fast Reroute

   Additional data object (in the OSPFv3 SRv6 model ) for fast reroute
   [RFC5286] is introduced by augmenting the fast-reroute container of
   the OSPF module.  It brings the ability to activate ipv6 TI-LFA
   (topology independent LFA) [I-D.ietf-rtgwg-segment-routing-ti-lfa].

3.4.  Micro-loop Avoidance

   OSPFv3 SRv6 model augments OSPF module with the micro-loop-avoidance
   container, this container including the leaf "srv6-enable" brings the
   ability to activate SRv6 avoid-microloop.

4.  YANG Module and Tree

4.1.  OSPFv3 SRv6 Model Tree

   The figure below describes the overall structure of the ospfv3-srv6
   YANG module:

 module: ietf-ospfv3-srv6
   augment /rt:routing/rt:control-plane-protocols
           /rt:control-plane-protocol/ospf:ospf:
      +--rw srv6
      |  +--rw enable?                 boolean
      |  +--rw default-locator?        boolean
      |  +--rw locator-name*    -> /rt:routing/srv6:srv6
      |                            /srv6:locators/srv6:locator/srv6:name
      |  +--rw persistent-end-x-sid?   boolean
      +--rw micro-loop-avoidance



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         +--rw srv6-enable?            boolean
         +--rw srv6-rib-update-delay?  uint16
   augment /rt:routing/rt:control-plane-protocols
           /rt:control-plane-protocol/ospf:ospf
           /ospf:fast-reroute:
      +--rw srv6-ti-lfa {srv6-ti-lfa}?
         +--rw enable?   boolean
   augment /rt:routing/rt:control-plane-protocols
           /rt:control-plane-protocol/ospf:ospf
           /ospf:database/ospf:as-scope-lsa-type
           /ospf:as-scope-lsas/ospf:as-scope-lsa
           /ospf:version/ospf:ospfv3
           /ospf:ospfv3/ospf:body:
      +--ro srv6-locator
         +--ro srv6-locactor-tlv
            +--ro route-type?       identityref
            +--ro algorithm?        uint8
            +--ro locator-length?   uint8
            +--ro flags?            bits
            +--ro metric?           uint32
            +--ro locator*          inet:ipv6-address-no-zone
            +--ro srv6-end-sid
               +--ro flags?                uint8
               +--ro endpoint-func
               |  +--ro fuc-flags?                 uint8
               |  +--ro endpoint-func?             identityref
               |  +--ro undefined-endpoint-func?   uint16
               +--ro sid?                  srv6-sid-value
               +--ro srv6-sid-structure
                  +--ro lb-length?    uint8
                  +--ro ln-length?    uint8
                  +--ro fun-length?   uint8
                  +--ro arg-length?   uint8
   augment /rt:routing
           /rt:control-plane-protocols/rt:control-plane-protocol
           /ospf:ospf/ospf:database
           /ospf:as-scope-lsa-type/ospf:as-scope-lsas
           /ospf:as-scope-lsa/ospf:version/ospf:ospfv3
           /ospf:ospfv3/ospf:body/ospf:router-information:
      +--ro srv6-capability
      |  +--ro flags?   bits
      +--ro srv6-msd
         +--ro max-segments-left?   uint8
         +--ro max-end-pop?         uint8
         +--ro max-h-encaps?        uint8
         +--ro max-end-d?           uint8
   augment /rt:routing/rt:control-plane-protocols
           /rt:control-plane-protocol/ospf:ospf/ospf:areas/ospf:area



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           /ospf:database/ospf:area-scope-lsa-type/ospf:area-scope-lsas
           /ospf:area-scope-lsa/ospf:version/ospf:ospfv3
           /ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router
           /ospfv3-e-lsa:e-router-tlvs
           /ospfv3-e-lsa:link-tlv:
      +--ro srv6-endx-sid
         +--ro endpoint-func
         |  +--ro fuc-flags?                 uint8
         |  +--ro endpoint-func?             identityref
         |  +--ro undefined-endpoint-func?   uint16
         +--ro flags?                bits
         +--ro algorithm?            uint8
         +--ro weight?               uint8
         +--ro sid*                  srv6-sid-value
         +--ro neighbor-router-id?   yang:dotted-quad
         +--ro srv6-sid-structure
            +--ro lb-length?    uint8
            +--ro ln-length?    uint8
            +--ro fun-length?   uint8
            +--ro arg-length?   uint8


4.2.  OSPFv3 SRv6 YANG Module

 <CODE BEGINS> file "ietf-ospfv3-srv6@2020-09-29.yang"
 module ietf-ospfv3-srv6 {
   yang-version 1.1;
   namespace "urn:ietf:params:xml:ns:"
           + "yang:ietf-ospfv3-srv6";
   prefix ospfv3-srv6;

   import ietf-yang-types {
     prefix "yang";
   }

   import ietf-routing {
     prefix "rt";
   }

   import ietf-ospfv3-extended-lsa {
     prefix "ospfv3-e-lsa";
   }

   import ietf-ospf {
     prefix "ospf";
   }

   import ietf-srv6-base {



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     prefix "srv6";
   }

   import ietf-inet-types {
     prefix "inet";
   }

   import ietf-segment-routing {
     prefix "sr";
   }

   organization
    "IETF LSR Working Group";

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

      Author:    Zhibo Hu
                 <mailto:huzhibo@huawei.com>
      Author:    Xuesong Geng
                 <mailto:gengxuesong@huawei.com>
      Author:    Kamran Raza
                 <mailto:skraza@cisco.com>
      Author:    Yingzhen Qu
                 <mailto:yingzhen.qu@futurewei.com>
      Author:    Acee Lindem
                 <mailto:acee@cisco.com>
     ";

   description
     "The YANG module defines a generic configuration model for
      Segment IPV6 routing OSPFv3 extensions common across all
      of the vendor implementations.

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

      Copyright (c) 2020 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
      (http://trustee.ietf.org/license-info).




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

      The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
      NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
      'MAY', and 'OPTIONAL' in this document are to be interpreted as
      described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
      they appear in all capitals, as shown here.";

   revision 2020-09-29 {
     description
       "Initial revision.";
     reference "draft-ietf-lsr-ospfv3-srv6-extensions-01";
   }

   /* Identities */
   identity SRV6_END_FUNC_TYPE {
     description
       "Base identity type for srv6 endpoint function code points.";
   }

   identity SRV6_END_FUNC_NO_PSP_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End (no PSP, no USP).";
   }

   identity SRV6_END_FUNC_PSP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End with PSP.";
   }

   identity SRV6_END_FUNC_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "END with USP.";
   }

   identity SRV6_END_FUNC_PSP_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "END with PSP & USP.";
   }

   identity SRV6_END_T_FUNC_NO_PSP_USP {
     base "SRV6_END_FUNC_TYPE";



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     description
       "End.T (no PSP, no USP).";
   }

   identity SRV6_END_T_FUNC_PSP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.T with PSP.";
   }

   identity SRV6_END_T_FUNC_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.T with USP.";
   }

   identity SRV6_END_T_FUNC_PSP_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.T with PSP & USP.";
   }

   identity SRV6_END_X_FUNC_NO_PSP_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.x (no PSP, no USP).";
   }

   identity SRV6_END_X_FUNC_PSP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.x with PSP.";
   }

   identity SRV6_END_X_FUNC_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.x with USP.";
   }

   identity SRV6_END_X_FUNC_PSP_USP {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.x with PSP & USP.";
   }

   identity SRV6_END_FUNC_DX6 {
     base "SRV6_END_FUNC_TYPE";



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     description
       "End.DX6 function.";
   }

   identity SRV6_END_FUNC_DT6 {
     base "SRV6_END_FUNC_TYPE";
     description
       "End.DT6 function.";
   }

   identity SRV6_END_FUNC_OTP {
     base "SRV6_END_FUNC_TYPE";
     description
       "END.OTP.";
   }

   identity s1-bit {
     base ospf:ospfv3-lsa-option;
     description
       "the S1/S2 bits are dependent on the desired
        flooding scope for the LSA.";
   }

   identity s2-bit {
     base ospf:ospfv3-lsa-option;
     description
       "the S1/S2 bits are dependent on the desired
        flooding scope for the LSA.";
   }

   identity srv6-locator-lsa {
     base ospf:ospfv3-lsa-type;
     description
       "SRv6 Locator LSA - Type TBD";
   }

   identity LOCATOR-ROUTE-TYPE {
     description
       "The type of the locator route.";
   }

   identity INTRA-AREA-LOCATOR {
     base "LOCATOR-ROUTE-TYPE";
     description
       "Intra-Area";
   }

   identity INTER-AREA-LOCATOR {



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     base "LOCATOR-ROUTE-TYPE";
     description
       "Inter-Area";
   }

   identity AS-EXTERNAL-LOCATOR {
     base "LOCATOR-ROUTE-TYPE";
     description
       "AS External";
   }

   identity NSSA-EXTERNAL-LOCATOR {
     base "LOCATOR-ROUTE-TYPE";
     description
       "NSSA External";
   }

   /* typedef */
   typedef srv6-sid-value {
     type inet:ipv6-address-no-zone;
     description
       "16 Octets encoded sid value.";
   }

   /* Features */
   feature srv6-ti-lfa {
     description
       "Enhance SRv6 FRR with ti-lfa
        support";
   }

   /* Groupings */
   grouping srv6-msds {
     description
       "Used to advertise node/link specific
        values for Maximum Sid Depths(MSD) of various types";
     container srv6-msd {
       description
       "Maximum SRv6 SID Depths.";
       leaf max-segments-left {
         type uint8;
         description
         "The Maximum Segments Left MSD Type specifies
          the maximum value of the 'SL' field in the SRH
          of a received packet before applying the Endpoint
          behavior associated with a SID.";
       }
       leaf max-end-pop {



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         type uint8;
         description
         "The Maximum End Pop MSD Type specifies the maximum
          number of SIDs in the SRH to which the router can
          apply 'PSP' or 'USP' behavior, as defined in flavors.";
       }
       leaf max-h-encaps {
         type uint8;
         description
         "The Maximum H.Encaps MSD Type specifies the maximum number
          of SIDs that can be included as part of the 'H.Encaps'
          behavior";
       }
       leaf max-end-d {
         type uint8;
         description
           "The maximum number of SIDs in an SRH when performing
            decapsulation associated with 'End.Dx' functions
            (e.g., 'End.DX6' and 'End.DT6').";
       }
     }
   }

   grouping srv6-capabilities {
     description
       "SRV6 capability grouping.";
     container srv6-capability {
       description
         "SRv6 capability.";
       leaf flags {
         type bits {
           bit o-flag {
             position 1;
             description
               "If set, then router is capable of supporting SRH O-bit
               ";
           }
         }
         description
           "Flags.";
        reference
          "I-D.ali-spring-srv6-oam: OAM in SRv6";
       }
     }
   }

   grouping srv6-endpoint-func {
     description



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       "This group defines srv6 endpoint function";
     container endpoint-func {
       description
         "Srv6 Endpoint function Descriptor.";
       leaf fuc-flags {
         type uint8;
         description
           "No function flags are currently being defined.";
       }
       leaf endpoint-func {
         type identityref {
           base SRV6_END_FUNC_TYPE;
         }
         description
           "The endpoint function.";
       }
       leaf undefined-endpoint-func {
         type uint16;
         description
           "Unknown endpoint func value.";
       }
     }
   }

   grouping srv6-end-sids {
     description
       "This group defines srv6 end sid";
     container srv6-end-sid {
       description
         "SRv6 Segment Identifier(SID) with Endpoint functions.";
       leaf flags {
         type uint8;
         description
           "NO flags are currently being defined.";
       }

       uses srv6-endpoint-func;
       leaf sid {
         type srv6-sid-value;
         description
           "SRV6 sid value.";
       }
       uses srv6-sid-structures;
     }
   }

   grouping srv6-sid-structures {
     description



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       "This group defines SRv6 SID Structure sub-TLV.";
     container srv6-sid-structure {
       description
         "SRv6 SID Structure sub-TLV is used to advertise the length
          of each individual part of the SRv6 SID as defined in
          [I-D.ietf-spring-srv6-network-programming]";
       leaf lb-length {
         type uint8;
         description
           "SRv6 SID Locator Block length in bits.";
       }

       leaf ln-length {
         type uint8;
         description
           "SRv6 SID Locator Node length in bits.";
       }

       leaf fun-length {
         type uint8;
         description
           "SRv6 SID Function length in bits.";
       }

       leaf arg-length {
         type uint8;
         description
           "SRv6 SID Argument length in bits.";
       }
     }
   }

   grouping srv6-endx-sids {
     description
       "This group defines SRv6 SIDs Associated with Adjacencies
       including SRv6 End.X SID Sub-TLV and SRv6 LAN End.X SID
       Sub-TLV.";
     container srv6-endx-sid {
       description
         "SRv6 sids associated with an adjacency.";

       uses srv6-endpoint-func;

       leaf flags {
         type bits {
           bit b-flag {
             position 0;
             description



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               "Backup Flag.  If set, the SID refers to a path that is
                eligible for protection";
           }
           bit s-flag {
             position 1;
             description
               "Set Flag.  When set, the S-Flag indicates that the
                End.X SID refers to a set of adjacencies (and therefore
                MAY be assigned to other adjacencies as well).";
           }
           bit p-flag {
             position 2;
             description
               "Persistent Flag: If set, the SID is persistently
                allocated, i.e., the SID value remains consistent
                across router restart and session/interface flap.";
           }
         }
         description
           "Flags for end.x subtlv.";
       }

       leaf algorithm {
         type uint8;
         description
           "Associated algorithm.";
       }

       leaf weight {
         type uint8;
         description
           "8 bit field whose value represents the weight of the End.X
            SID for the purpose of load balancing";
       }

       leaf-list sid {
         type srv6-sid-value;
         description
           "SRV6 sid value.";
       }

       leaf neighbor-router-id {
          type yang:dotted-quad;
          description
            "Neighbor router ID.This is only
             used on LAN adjacencies.";
       }




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       uses srv6-sid-structures;
     }
   }

   grouping srv6-locactor-tlvs {
     description
       "This group defines srv6 locator tlv.";
     container srv6-locactor-tlv {
       description
         "This contains a srv6 locator tlv.";
       leaf route-type {
         type identityref {
           base LOCATOR-ROUTE-TYPE;
         }
         description
           "The type of the locator route";
       }

       leaf algorithm {
         type uint8;
         description
           "Associated algorithm.";
       }

       leaf locator-length {
         type uint8;
         description
           "Carries the length of the Locator
            prefix as number of bits (1-128)";
       }

       leaf flags {
         type bits {
           bit n-flag {
             position 0;
             description
               "When the locator uniquely identifies a node in the
                network (i.e. it is provisioned on one and only one
                node), the N bit MUST be set.  Otherwise, this bit
                MUST be clear";
           }
           bit a-flag {
             position 1;
             description
               "When the Locator is configured as anycast, the A bit
                SHOULD be set.  Otherwise, this bit MUST be clear";
           }
         }



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         description
           "Flags for srv6 locator tlv.";
       }

       leaf metric {
         type uint32;
         description
           "Metric value.";
       }

       leaf-list locator {
         type inet:ipv6-address-no-zone;
         description
           "Advertised SRV6 locator.";
       }
       uses srv6-end-sids;
     }
   }

   /* Cfg */
   augment "/rt:routing/" +
           "rt:control-plane-protocols/rt:control-plane-protocol"+
           "/ospf:ospf" {
     when "/rt:routing/rt:control-plane-protocols/"+
          "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" {
       description
         "This augment OSPFv3 routing protocol when used";
     }
     description
       "This augments OSPFv3 protocol configuration
        with SRv6.";
     container srv6{
       leaf enable{
         type boolean;
         default "false";
         description
           "Enables SRv6 protocol extensions.";
       }
       leaf default-locator {
         type boolean;
         default "false";
         description
           "Enable OSPFv3 segment-routing IPv6 with default Locator.";
       }
       leaf-list locator-name {
         when "not(../default-locator='true')" {
           description
             "Only applies to non default locator.";



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         }
         type leafref {
           path "/rt:routing/sr:segment-routing/srv6:srv6"
              + "/srv6:locators/srv6:locator/srv6:name";
         }
         description
           "Enable OSPFv3 segment-routing IPv6 with specified Locator.";
       }
       leaf persistent-end-x-sid{
         type boolean;
         default "false";
         description
           "Enable the persistent nature of End.X sid";
       }
       description
         "Configuration about OSPFv3 segment-routing IPv6.";
     }

     container micro-loop-avoidance {
       leaf srv6-enable {
         type boolean;
         default "false";
         description
           "Enable SRv6 avoid-microloop.Depend on SR IPv6 Enable.";
       }

       leaf srv6-rib-update-delay {
         type uint16 {
           range "1000..10000";
         }
         units "ms";
         default "5000";
         description
           "Set the route delivery delay for SRv6 avoid-microloop.
            Depend on SR IPv6 Enable.";
       }

       description
         "Enable OSPFv3 avoid-microloop.";
     }
   }

   augment "/rt:routing/" +
           "rt:control-plane-protocols/rt:control-plane-protocol"+
           "/ospf:ospf/ospf:fast-reroute"{
     when "/rt:routing/rt:control-plane-protocols/"+
          "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'"{
       description



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         "This augment OSPFv3 routing protocol when used";
     }
     description
       "This augments OSPFv3 IP FRR with IPV6 TILFA.";

     container srv6-ti-lfa {
       if-feature srv6-ti-lfa;
       leaf enable {
         type boolean;
         description
           "Enables SRv6 TI-LFA computation.";
       }
       description
         "SRv6 TILFA configuration.";
     }
   }

   /* Database */
   augment "/rt:routing/"
            + "rt:control-plane-protocols/rt:control-plane-protocol/"
            + "ospf:ospf/ospf:database/"
            + "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
            + "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
            + "ospf:ospfv3/ospf:body" {
     when "/rt:routing/rt:control-plane-protocols/"+
          "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" {
       description
         "This augment OSPFv3 routing protocol when used";
     }
     description
       "This augments OSPFv3 protocol router capability.";
     container srv6-locator {
       description
         "SRv6 Locator LSA.";
       uses srv6-locactor-tlvs;
     }
   }

   augment "/rt:routing/"
            + "rt:control-plane-protocols/rt:control-plane-protocol/"
            + "ospf:ospf/ospf:database/"
            + "ospf:as-scope-lsa-type/ospf:as-scope-lsas/"
            + "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/"
            + "ospf:ospfv3/ospf:body/ospf:router-information" {
     when "/rt:routing/rt:control-plane-protocols/"+
          "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" {
       description
         "This augment OSPFv3 routing protocol when used";



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     }
     description
       "This augments OSPFv3 protocol router capability.";
     uses srv6-capabilities;
     uses srv6-msds;
   }

   augment "/rt:routing/rt:control-plane-protocols"
         + "/rt:control-plane-protocol/ospf:ospf/ospf:areas/ospf:area"
         + "/ospf:database/ospf:area-scope-lsa-type"
         + "/ospf:area-scope-lsas"
         + "/ospf:area-scope-lsa/ospf:version/ospf:ospfv3"
         + "/ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router/"
         + "ospfv3-e-lsa:e-router-tlvs/"
         + "ospfv3-e-lsa:link-tlv" {
     when "/rt:routing/rt:control-plane-protocols/"+
          "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" {
     }
     description
       "This augments OSPFv3 protocol neighbor.";
     uses srv6-endx-sids;
   }

   /* Notifications */
 }
 <CODE ENDS>

5.  Security Considerations

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

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

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




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   effect on network operations.  These are the subtrees and data nodes
   and their sensitivity/vulnerability:

   o  srv6

   o  micro-loop-avoidance

   o  srv6-ti-lfa

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

   o  srv6-locator

   o  srv6-capability

   o  srv6-msd

   o  srv6-endx-sid

6.  Contributors

      Qin Wu
      Huawei
      Email: bill.wu@huawei.com

7.  Acknowledgements

   TBD.

8.  IANA Considerations

   The IANA is requested to assign two new URIs from the IETF XML
   registry ([RFC3688]).  Authors are suggesting the following URI:


                 URI: urn:ietf:params:xml:ns:yang:ietf-ospfv3-srv6
                 Registrant Contact: The IESG.
                 XML: N/A, the requested URI is an XML namespace

   This document also requests one new YANG module name in the YANG
   Module Names registry ([RFC6020]) with the following suggestion :




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              name: ietf-ospfv3-srv6
              namespace: urn:ietf:params:xml:ns:yang:ietf-ospfv3-srv6
              prefix: ospfv3-srv6
              reference: RFC XXXX

9.  References

   [I-D.ietf-lsr-ospfv3-extended-lsa-yang]
              Lindem, A., Palani, S., and Y. Qu, "YANG Model for OSPFv3
              Extended LSAs", draft-ietf-lsr-ospfv3-extended-lsa-yang-08
              (work in progress), March 2021.

   [I-D.ietf-lsr-ospfv3-srv6-extensions]
              Li, Z., Hu, Z., Cheng, D., Talaulikar, K., and P. Psenak,
              "OSPFv3 Extensions for SRv6", draft-ietf-lsr-
              ospfv3-srv6-extensions-02 (work in progress), February
              2021.

   [I-D.ietf-ospf-yang]
              Yeung, D., Qu, Y., Zhang, J., Chen, I., and A. Lindem,
              "YANG Data Model for OSPF Protocol", draft-ietf-ospf-
              yang-29 (work in progress), October 2019.

   [I-D.ietf-rtgwg-segment-routing-ti-lfa]
              Litkowski, S., Bashandy, A., Filsfils, C., Francois, P.,
              Decraene, B., and D. Voyer, "Topology Independent Fast
              Reroute using Segment Routing", draft-ietf-rtgwg-segment-
              routing-ti-lfa-06 (work in progress), February 2021.

   [I-D.ietf-spring-srv6-yang]
              Raza, K., Agarwal, S., Liu, X., Hu, Z., Hussain, I., Shah,
              H., Voyer, D., Matsushima, S., Horiba, K., AbdelSalam, A.,
              and J. Rajamanickam, "YANG Data Model for SRv6 Base and
              Static", draft-ietf-spring-srv6-yang-00 (work in
              progress), September 2020.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

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







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

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

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012,
              <https://www.rfc-editor.org/info/rfc6536>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

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

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

   [RFC9020]  Litkowski, S., Qu, Y., Lindem, A., Sarkar, P., and J.
              Tantsura, "YANG Data Model for Segment Routing", RFC 9020,
              DOI 10.17487/RFC9020, May 2021,
              <https://www.rfc-editor.org/info/rfc9020>.

Authors' Addresses

   Zhibo Hu
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: huzhibo@huawei.com





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   Xuesong Geng
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: gengxuesong@huawei.com


   Kamran Raza
   Cisco Systems, Inc.
   2000 Innovation Drive Kanata, ON K2K-3E8 CA

   Email: skraza@cisco.com


   Yingzhen Qu
   Futurewei Technologies
   2330 Central Express Way
   Santa Clara  950950
   USA

   Email: yingzhen.qu@futurewei.com


   Acee Lindem
   Cisco Systems
   301 Midenhall Way
   Cary, NC  27513
   USA

   Email: acee@cisco.com



















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