Internet Engineering Task Force (IETF)                         L. Lhotka
Request for Comments: 8349                                        CZ.NIC
Obsoletes: 8022                                                A. Lindem
Category: Standards Track                                  Cisco Systems
ISSN: 2070-1721                                                    Y. Qu
                                                                 Huawei
                                                             March 2018


       A YANG Data Model for Routing Management (NMDA Version)

Abstract

  This document specifies three YANG modules 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 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.

  The YANG modules in this document conform to the Network Management
  Datastore Architecture (NMDA).  This document obsoletes RFC 8022.

Status of This Memo

  This is an Internet Standards Track document.

  This document is a product of the Internet Engineering Task Force
  (IETF).  It represents the consensus of the IETF community.  It has
  received public review and has been approved for publication by the
  Internet Engineering Steering Group (IESG).  Further information on
  Internet Standards is available in Section 2 of RFC 7841.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  https://www.rfc-editor.org/info/rfc8349.













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Copyright Notice

  Copyright (c) 2018 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.





































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Table of Contents

  1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
  2.  Terminology and Notation  . . . . . . . . . . . . . . . . . .   4
    2.1.  Glossary of New Terms . . . . . . . . . . . . . . . . . .   5
    2.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   6
    2.3.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   6
  3.  Objectives  . . . . . . . . . . . . . . . . . . . . . . . . .   6
  4.  The Design of the Core Routing Data Model . . . . . . . . . .   7
    4.1.  System-Controlled and User-Controlled List Entries  . . .   8
  5.  Basic Building Blocks . . . . . . . . . . . . . . . . . . . .   9
    5.1.  Routes  . . . . . . . . . . . . . . . . . . . . . . . . .   9
    5.2.  Routing Information Base (RIB)  . . . . . . . . . . . . .  10
    5.3.  Control-Plane Protocol  . . . . . . . . . . . . . . . . .  11
      5.3.1.  Routing Pseudo-Protocols  . . . . . . . . . . . . . .  11
      5.3.2.  Defining New Control-Plane Protocols  . . . . . . . .  11
    5.4.  Parameters of IPv6 Router Advertisements  . . . . . . . .  12
  6.  Interactions with Other YANG Modules  . . . . . . . . . . . .  13
    6.1.  Module "ietf-interfaces"  . . . . . . . . . . . . . . . .  13
    6.2.  Module "ietf-ip"  . . . . . . . . . . . . . . . . . . . .  14
  7.  Routing Management YANG Module  . . . . . . . . . . . . . . .  15
  8.  IPv4 Unicast Routing Management YANG Module . . . . . . . . .  29
  9.  IPv6 Unicast Routing Management YANG Module . . . . . . . . .  37
    9.1.  IPv6 Router Advertisements Submodule  . . . . . . . . . .  45
  10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  56
  11. Security Considerations . . . . . . . . . . . . . . . . . . .  57
  12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  58
    12.1.  Normative References . . . . . . . . . . . . . . . . . .  58
    12.2.  Informative References . . . . . . . . . . . . . . . . .  60
  Appendix A.  The Complete Schema Tree . . . . . . . . . . . . . .  61
  Appendix B.  Minimum Implementation . . . . . . . . . . . . . . .  66
  Appendix C.  Example: Adding a New Control-Plane Protocol . . . .  67
  Appendix D.  Data Tree Example  . . . . . . . . . . . . . . . . .  70
  Appendix E.  NETCONF Get Data Reply Example . . . . . . . . . . .  77
  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  80
  Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  80















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1.  Introduction

  This document specifies the following YANG modules:

  o  The "ietf-routing" module provides generic components of a routing
     data model.

  o  The "ietf-ipv4-unicast-routing" module augments the "ietf-routing"
     module with additional data specific to IPv4 unicast.

  o  The "ietf-ipv6-unicast-routing" module augments the "ietf-routing"
     module with additional data specific to IPv6 unicast.  Its
     submodule, "ietf-ipv6-router-advertisements", also augments the
     "ietf-interfaces"  [RFC8343] and "ietf-ip" [RFC8344] modules with
     IPv6 router configuration variables required by [RFC4861].

  These modules together define the core routing data model, which is
  intended as a basis for future data model development covering
  more-sophisticated routing systems.  While these three modules can be
  directly used for simple IP devices with static routing (see
  Appendix B), their main purpose is to provide essential building
  blocks for more-complicated data models involving multiple
  control-plane protocols, multicast routing, additional address
  families, and advanced functions such as route filtering or policy
  routing.  To this end, it is expected that the core routing data
  model will be augmented by numerous modules developed by various IETF
  working groups.

  The YANG modules in this document conform to the Network Management
  Datastore Architecture (NMDA) [RFC8342].  This document obsoletes
  RFC 8022 [RFC8022].

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




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  o  system state

  o  operational state

  o  intended configuration

  The following terms are defined in [RFC7950]:

  o  action

  o  augment

  o  container

  o  data model

  o  data node

  o  feature

  o  leaf

  o  list

  o  mandatory node

  o  module

  o  presence container

  o  schema tree

  o  RPC (Remote Procedure Call) operation

2.1.  Glossary of New Terms

  core routing data model:  YANG data model comprising "ietf-routing",
     "ietf-ipv4-unicast-routing", and "ietf-ipv6-unicast-routing"
     modules.

  direct route:  A route to a directly connected network.

  Routing Information Base (RIB):  An object containing a list of
     routes, together with other information.  See Section 5.2 for
     details.






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  system-controlled entry:  An entry in a list in the operational state
     ("config false") that is created by the system independently of
     what has been explicitly configured.  See Section 4.1 for details.

  user-controlled entry:  An entry in a list in the operational state
     ("config false") that is created and deleted as a direct
     consequence of certain configuration changes.  See Section 4.1 for
     details.

2.2.  Tree Diagrams

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

2.3.  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 |
           +--------+---------------------------+-----------+
           | if     | ietf-interfaces           | [RFC8343] |
           | ip     | ietf-ip                   | [RFC8344] |
           | rt     | ietf-routing              | Section 7 |
           | v4ur   | ietf-ipv4-unicast-routing | Section 8 |
           | v6ur   | ietf-ipv6-unicast-routing | Section 9 |
           | yang   | ietf-yang-types           | [RFC6991] |
           | inet   | ietf-inet-types           | [RFC6991] |
           +--------+---------------------------+-----------+

            Table 1: Prefixes and Corresponding YANG Modules

3.  Objectives

  The initial design of the core routing data model was driven by the
  following objectives:

  o  The data model should be suitable for the common address families
     -- in particular, IPv4 and IPv6 -- and for unicast and multicast
     routing, as well as Multiprotocol Label Switching (MPLS).

  o  A simple IP routing system, such as one that uses only static
     routing, should be configurable in a simple way, ideally without
     any need to develop additional YANG modules.



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  o  On the other hand, the core routing framework must allow for
     complicated implementations involving multiple RIBs and multiple
     control-plane protocols, as well as controlled redistributions of
     routing information.

  o  Because device vendors will want to map the data models built on
     this generic framework to their proprietary data models and
     configuration interfaces, the framework should be flexible enough
     to facilitate such mapping and accommodate data models with
     different logic.

4.  The Design of the Core Routing Data Model

  The core routing data model consists of three YANG modules and one
  submodule.  The first module, "ietf-routing", defines the generic
  components of a routing system.  The other two modules --
  "ietf-ipv4-unicast-routing" and "ietf-ipv6-unicast-routing" --
  augment the "ietf-routing" module with additional data nodes that are
  needed for IPv4 and IPv6 unicast routing, respectively.  The
  "ietf-ipv6-unicast-routing" module has a submodule,
  "ietf-ipv6-router-advertisements", that augments the
  "ietf-interfaces" [RFC8343] and "ietf-ip" [RFC8344] modules with
  configuration variables for IPv6 Router Advertisements as required by
  [RFC4861].



























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  Figure 1 shows abridged views of the hierarchies.  See Appendix A for
  the complete data trees.

  +--rw routing
     +--rw router-id?                 yang:dotted-quad
     +--ro interfaces
     |  +--ro interface*   if:interface-ref
     +--rw control-plane-protocols
     |  +--rw control-plane-protocol* [type name]
     |     +--rw type             identityref
     |     +--rw name             string
     |     +--rw description?     string
     |     +--rw static-routes
     |        +--rw v4ur:ipv4
     |        |     ...
     |        +--rw v6ur:ipv6
     |              ...
     +--rw ribs
        +--rw rib* [name]
           +--rw name              string
           +--rw address-family?   identityref
           +--ro default-rib?      boolean {multiple-ribs}?
           +--ro routes
           |  +--ro route*
           |        ...
           +---x active-route
           |  +---w input
           |  |  +---w v4ur:destination-address?   inet:ipv4-address
           |  |  +---w v6ur:destination-address?   inet:ipv6-address
           |  +--ro output
           |        ...
           +--rw description?      string

                        Figure 1: Data Hierarchy

  As can be seen from Figure 1, the core routing data model introduces
  several generic components of a routing framework: routes, RIBs
  containing lists of routes, and control-plane protocols.  Section 5
  describes these components in more detail.

4.1.  System-Controlled and User-Controlled List Entries

  The core routing data model defines several lists in the schema tree,
  such as "rib", that have to be populated with at least one entry in
  any properly functioning device, and additional entries may be
  configured by a client.





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  In such a list, the server creates the required item as a
  "system-controlled entry" in the operational state, i.e., inside
  read-only lists in the "routing" container.

  An example can be seen in Appendix D: the "/routing/ribs/rib" list
  has two system-controlled entries -- "ipv4-master" and "ipv6-master".

  Additional entries called "user-controlled entries" may be created in
  the configuration by a client, e.g., via the Network Configuration
  Protocol (NETCONF).  If the server accepts a configured
  user-controlled entry, then this entry also appears in the
  operational state version of the list.

  Corresponding entries in both versions of the list (in the intended
  configuration and the operational state) [RFC8342] have the same
  value of the list key.

  A client may also provide supplemental configuration of system-
  controlled entries.  To do so, the client creates a new entry in the
  configuration with the desired contents.  In order to bind this entry
  to the corresponding entry in the operational state, the key of the
  configuration entry has to be set to the same value as the key of the
  operational state entry.

  Deleting a user-controlled entry from the intended configuration
  results in the removal of the corresponding entry in the operational
  state list.  In contrast, if a client deletes a system-controlled
  entry from the intended configuration, only the extra configuration
  specified in that entry is removed; the corresponding operational
  state entry is not removed.

5.  Basic Building Blocks

  This section describes the essential components of the core routing
  data model.

5.1.  Routes

  Routes are basic elements of information in a routing system.  The
  core routing data model defines only the following minimal set of
  route attributes:

  o  "destination-prefix": address prefix specifying the set of
     destination addresses for which the route may be used.  This
     attribute is mandatory.






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  o  "route-preference": an integer value (also known as
     "administrative distance") that is used for selecting a preferred
     route among routes with the same destination prefix.  A lower
     value indicates a route that is more preferred.

  o  "next-hop": determines the outgoing interface and/or next-hop
     address(es), or a special operation to be performed on a packet.

  Routes are primarily system state and appear as entries in RIBs
  (Section 5.2), but they may also be found in configuration data --
  for example, as manually configured static routes.  In the latter
  case, configurable route attributes are generally a subset of
  attributes defined for RIB routes.

5.2.  Routing Information Base (RIB)

  Every implementation of the core routing data model manages one or
  more RIBs.  A RIB is a list of routes complemented with
  administrative data.  Each RIB contains only routes of one address
  family.  An address family is represented by an identity derived from
  the "rt:address-family" base identity.

  In the core routing data model, RIBs are represented as entries in
  the list "/routing/ribs/rib" in the operational state.  The contents
  of RIBs are controlled and manipulated by control-plane protocol
  operations that may result in route additions, removals, and
  modifications.  This also includes manipulations via the "static"
  and/or "direct" pseudo-protocols; see Section 5.3.1.

  For every supported address family, exactly one RIB MUST be marked as
  the "default RIB", in which control-plane protocols place their
  routes by default.

  Simple router implementations that do not advertise the
  "multiple-ribs" feature will typically create one system-controlled
  RIB per supported address family and mark it as the default RIB.

  More-complex router implementations advertising the "multiple-ribs"
  feature support multiple RIBs per address family that can be used for
  policy routing and other purposes.

  The following action (see Section 7.15 of [RFC7950]) is defined for
  the "rib" list:

  o  active-route -- return the active RIB route for the destination
     address that is specified as the action's input parameter.





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5.3.  Control-Plane Protocol

  The core routing data model provides an open-ended framework for
  defining multiple control-plane protocol instances, e.g., for Layer 3
  routing protocols.  Each control-plane protocol instance MUST be
  assigned a type, which is an identity derived from the
  "rt:control-plane-protocol" base identity.  The core routing data
  model defines two identities for the "direct" and "static"
  pseudo-protocols (Section 5.3.1).

  Multiple control-plane protocol instances of the same type MAY be
  configured.

5.3.1.  Routing Pseudo-Protocols

  The core routing data model defines two special routing protocol
  types -- "direct" and "static".  Both are in fact pseudo-protocols,
  which means that they are confined to the local device and do not
  exchange any routing information with adjacent routers.

  Every implementation of the core routing data model MUST provide
  exactly one instance of the "direct" pseudo-protocol type.  It is the
  source of direct routes for all configured address families.  Direct
  routes are normally supplied by the operating system kernel, based on
  the configuration of network interface addresses; see Section 6.2.

  A pseudo-protocol of the type "static" allows for specifying routes
  manually.  It MAY be configured in zero or multiple instances,
  although a typical configuration will have exactly one instance.

5.3.2.  Defining New Control-Plane Protocols

  It is expected that future YANG modules will create data models for
  additional control-plane protocol types.  Such new modules will have
  to define the protocol-specific data nodes, and they will have to
  integrate into the core routing framework in the following way:

  o  A new identity MUST be defined for the control-plane protocol, and
     its base identity MUST be set to "rt:control-plane-protocol" or to
     an identity derived from "rt:control-plane-protocol".











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  o  Additional route attributes MAY be defined, preferably in one
     place by means of defining a YANG grouping.  The new attributes
     have to be inserted by augmenting the definitions of the node

      /rt:routing/rt:ribs/rt:rib/rt:routes/rt:route

     and possibly other places in the schema tree.

  o  Data nodes for the new protocol can be defined by augmenting the
     "control-plane-protocol" data node under "/routing".

  By using a "when" statement, the augmented data nodes specific to the
  new protocol SHOULD be made conditional and valid only if the value
  of "rt:type" or "rt:source-protocol" is equal to (or derived from)
  the new protocol's identity.

  It is also RECOMMENDED that protocol-specific data nodes be
  encapsulated in an appropriately named container with presence.  Such
  a container may contain mandatory data nodes that are otherwise
  forbidden at the top level of an augment.

  The above steps are implemented by the example YANG module for the
  Routing Information Protocol (RIP); see Appendix C.

5.4.  Parameters of IPv6 Router Advertisements

  The YANG module "ietf-ipv6-router-advertisements" (Section 9.1),
  which is a submodule of the "ietf-ipv6-unicast-routing" module,
  augments the schema tree of IPv6 interfaces with definitions of the
  following variables as required by Section 6.2.1 of [RFC4861]:

  o  send-advertisements

  o  max-rtr-adv-interval

  o  min-rtr-adv-interval

  o  managed-flag

  o  other-config-flag

  o  link-mtu

  o  reachable-time

  o  retrans-timer

  o  cur-hop-limit



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  o  default-lifetime

  o  prefix-list: a list of prefixes to be advertised.

     The following parameters are associated with each prefix in
     the list:

     *  valid-lifetime

     *  on-link-flag

     *  preferred-lifetime

     *  autonomous-flag

  NOTES:

  1.  The "IsRouter" flag, which is also required by [RFC4861], is
      implemented in the "ietf-ip" module [RFC8344] (leaf
      "ip:forwarding").

  2.  The Neighbor Discovery specification [RFC4861] allows the
      implementations to decide whether the "valid-lifetime" and
      "preferred-lifetime" parameters remain the same in consecutive
      advertisements or decrement in real time.  However, the latter
      behavior seems problematic because the values might be reset
      again to the (higher) configured values after a configuration is
      reloaded.  Moreover, no implementation is known to use the
      decrementing behavior.  The "ietf-ipv6-router-advertisements"
      submodule therefore stipulates the former behavior with constant
      values.

6.  Interactions with Other YANG Modules

  The semantics of the core routing data model also depends on several
  configuration parameters that are defined in other YANG modules.

6.1.  Module "ietf-interfaces"

  The following boolean switch is defined in the "ietf-interfaces" YANG
  module [RFC8343]:

  /if:interfaces/if:interface/if:enabled

     If this switch is set to "false" for a network-layer interface,
     then all routing and forwarding functions MUST be disabled on this
     interface.




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6.2.  Module "ietf-ip"

  The following boolean switches are defined in the "ietf-ip" YANG
  module [RFC8344]:

  /if:interfaces/if:interface/ip:ipv4/ip:enabled

     If this switch is set to "false" for a network-layer interface,
     then all IPv4 routing and forwarding functions MUST be disabled on
     this interface.

  /if:interfaces/if:interface/ip:ipv4/ip:forwarding

     If this switch is set to "false" for a network-layer interface,
     then the forwarding of IPv4 datagrams through this interface MUST
     be disabled.  However, the interface MAY participate in other IPv4
     routing functions, such as routing protocols.

  /if:interfaces/if:interface/ip:ipv6/ip:enabled

     If this switch is set to "false" for a network-layer interface,
     then all IPv6 routing and forwarding functions MUST be disabled on
     this interface.

  /if:interfaces/if:interface/ip:ipv6/ip:forwarding

     If this switch is set to "false" for a network-layer interface,
     then the forwarding of IPv6 datagrams through this interface MUST
     be disabled.  However, the interface MAY participate in other IPv6
     routing functions, such as routing protocols.

  In addition, the "ietf-ip" module allows for configuring IPv4 and
  IPv6 addresses and network prefixes or masks on network-layer
  interfaces.  Configuration of these parameters on an enabled
  interface MUST result in an immediate creation of the corresponding
  direct route.  The destination prefix of this route is set according
  to the configured IP address and network prefix/mask, and the
  interface is set as the outgoing interface for that route.













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RFC 8349                 YANG Routing Management              March 2018


7.  Routing Management YANG Module

  <CODE BEGINS> file "[email protected]"

  module ietf-routing {
    yang-version "1.1";
    namespace "urn:ietf:params:xml:ns:yang:ietf-routing";
    prefix "rt";

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

    import ietf-interfaces {
      prefix "if";
      description
        "An 'ietf-interfaces' module version that is compatible with
         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    organization
      "IETF NETMOD (Network Modeling) Working Group";
    contact
      "WG Web:   <https://datatracker.ietf.org/wg/netmod/>
       WG List:  <mailto:[email protected]>

       Editor:   Ladislav Lhotka
                 <mailto:[email protected]>
                 Acee Lindem
                 <mailto:[email protected]>
                 Yingzhen Qu
                 <mailto:[email protected]>";

    description
      "This YANG module defines essential components for the management
       of a routing subsystem.  The model fully conforms to the Network
       Management Datastore Architecture (NMDA).

       Copyright (c) 2018 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).



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RFC 8349                 YANG Routing Management              March 2018


       This version of this YANG module is part of RFC 8349; see
       the RFC itself for full legal notices.";

    revision 2018-03-13 {
      description
        "Network Management Datastore Architecture (NMDA) revision.";
      reference
        "RFC 8349: A YANG Data Model for Routing Management
                   (NMDA Version)";
    }

    revision 2016-11-04 {
         description
           "Initial revision.";
         reference
           "RFC 8022: A YANG Data Model for Routing Management";
    }

    /* Features */
    feature multiple-ribs {
      description
        "This feature indicates that the server supports
         user-defined RIBs.

         Servers that do not advertise this feature SHOULD provide
         exactly one system-controlled RIB per supported address family
         and also make it the default RIB.  This RIB then appears as an
         entry in the list '/routing/ribs/rib'.";
    }

    feature router-id {
      description
        "This feature indicates that the server supports an explicit
         32-bit router ID that is used by some routing protocols.

         Servers that do not advertise this feature set a router ID
         algorithmically, usually to one of the configured IPv4
         addresses.  However, this algorithm is implementation
         specific.";
    }

    /* Identities */

    identity address-family {
      description
        "Base identity from which identities describing address
         families are derived.";
    }



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RFC 8349                 YANG Routing Management              March 2018


    identity ipv4 {
      base address-family;
      description
        "This identity represents an IPv4 address family.";
    }

    identity ipv6 {
      base address-family;
      description
        "This identity represents an IPv6 address family.";
    }

    identity control-plane-protocol {
      description
        "Base identity from which control-plane protocol identities are
         derived.";
    }

    identity routing-protocol {
      base control-plane-protocol;
      description
        "Identity from which Layer 3 routing protocol identities are
         derived.";
    }

    identity direct {
      base routing-protocol;
      description
        "Routing pseudo-protocol that provides routes to directly
         connected networks.";
    }

    identity static {
      base routing-protocol;
      description
        "'Static' routing pseudo-protocol.";
    }

    /* Type Definitions */

    typedef route-preference {
      type uint32;
      description
        "This type is used for route preferences.";
    }

    /* Groupings */




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RFC 8349                 YANG Routing Management              March 2018


    grouping address-family {
      description
        "This grouping provides a leaf identifying an address
         family.";
      leaf address-family {
        type identityref {
          base address-family;
        }
        mandatory true;
        description
          "Address family.";
      }
    }

    grouping router-id {
      description
        "This grouping provides a router ID.";
      leaf router-id {
        type yang:dotted-quad;
        description
          "A 32-bit number in the form of a dotted quad that is used by
           some routing protocols identifying a router.";
        reference
          "RFC 2328: OSPF Version 2";
      }
    }

    grouping special-next-hop {
      description
        "This grouping provides a leaf with an enumeration of special
         next hops.";
      leaf special-next-hop {
        type enumeration {
          enum blackhole {
            description
              "Silently discard the packet.";
          }
          enum unreachable {
            description
              "Discard the packet and notify the sender with an error
               message indicating that the destination host is
               unreachable.";
          }
          enum prohibit {
            description
              "Discard the packet and notify the sender with an error
               message indicating that the communication is
               administratively prohibited.";



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          }
          enum receive {
            description
              "The packet will be received by the local system.";
          }
        }
        description
          "Options for special next hops.";
      }
    }

    grouping next-hop-content {
      description
        "Generic parameters of next hops in static routes.";
      choice next-hop-options {
        mandatory true;
        description
          "Options for next hops in static routes.

           It is expected that further cases will be added through
           augments from other modules.";
        case simple-next-hop {
          description
            "This case represents a simple next hop consisting of the
             next-hop address and/or outgoing interface.

             Modules for address families MUST augment this case with a
             leaf containing a next-hop address of that address
             family.";
          leaf outgoing-interface {
            type if:interface-ref;
            description
              "Name of the outgoing interface.";
          }
        }
        case special-next-hop {
          uses special-next-hop;
        }
        case next-hop-list {
          container next-hop-list {
            description
              "Container for multiple next hops.";
            list next-hop {
              key "index";
              description
                "An entry in a next-hop list.

                 Modules for address families MUST augment this list



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RFC 8349                 YANG Routing Management              March 2018


                 with a leaf containing a next-hop address of that
                 address family.";
              leaf index {
                type string;
                description
                  "A user-specified identifier utilized to uniquely
                   reference the next-hop entry in the next-hop list.
                   The value of this index has no semantic meaning
                   other than for referencing the entry.";
              }
              leaf outgoing-interface {
                type if:interface-ref;
                description
                  "Name of the outgoing interface.";
              }
            }
          }
        }
      }
    }

    grouping next-hop-state-content {
      description
        "Generic state parameters of next hops.";
      choice next-hop-options {
        mandatory true;
        description
          "Options for next hops.

           It is expected that further cases will be added through
           augments from other modules, e.g., for recursive
           next hops.";
        case simple-next-hop {
          description
            "This case represents a simple next hop consisting of the
             next-hop address and/or outgoing interface.

             Modules for address families MUST augment this case with a
             leaf containing a next-hop address of that address
             family.";
          leaf outgoing-interface {
            type if:interface-ref;
            description
              "Name of the outgoing interface.";
          }
        }
        case special-next-hop {
          uses special-next-hop;



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        }
        case next-hop-list {
          container next-hop-list {
            description
              "Container for multiple next hops.";
            list next-hop {
              description
                "An entry in a next-hop list.

                 Modules for address families MUST augment this list
                 with a leaf containing a next-hop address of that
                 address family.";
              leaf outgoing-interface {
                type if:interface-ref;
                description
                  "Name of the outgoing interface.";
              }
            }
          }
        }
      }
    }

    grouping route-metadata {
      description
        "Common route metadata.";
      leaf source-protocol {
        type identityref {
          base routing-protocol;
        }
        mandatory true;
        description
          "Type of the routing protocol from which the route
           originated.";
      }
      leaf active {
        type empty;
        description
          "The presence of this leaf indicates that the route is
           preferred among all routes in the same RIB that have the
           same destination prefix.";
      }
      leaf last-updated {
        type yang:date-and-time;
        description
          "Timestamp of the last modification of the route.  If the
           route was never modified, it is the time when the route was
           inserted into the RIB.";



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      }
    }

    /* Data nodes */

    container routing {
      description
        "Configuration parameters for the routing subsystem.";
      uses router-id {
        if-feature "router-id";
        description
          "Support for the global router ID.  Routing protocols
           that use a router ID can use this parameter or override it
           with another value.";
      }
      container interfaces {
        config false;
        description
          "Network-layer interfaces used for routing.";
        leaf-list interface {
          type if:interface-ref;
          description
            "Each entry is a reference to the name of a configured
             network-layer interface.";
        }
      }
      container control-plane-protocols {
        description
          "Support for control-plane protocol instances.";
        list control-plane-protocol {
          key "type name";
          description
            "Each entry contains a control-plane protocol instance.";
          leaf type {
            type identityref {
              base control-plane-protocol;
            }
            description
              "Type of the control-plane protocol -- an identity
               derived from the 'control-plane-protocol'
               base identity.";
          }
          leaf name {
            type string;
            description
              "An arbitrary name of the control-plane protocol
               instance.";
          }



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RFC 8349                 YANG Routing Management              March 2018


          leaf description {
            type string;
            description
              "Textual description of the control-plane protocol
               instance.";
          }
          container static-routes {
            when "derived-from-or-self(../type, 'rt:static')" {
              description
                "This container is only valid for the 'static' routing
                 protocol.";
            }
            description
              "Support for the 'static' pseudo-protocol.

               Address-family-specific modules augment this node with
               their lists of routes.";
          }
        }
      }
      container ribs {
        description
          "Support for RIBs.";
        list rib {
          key "name";
          description
            "Each entry contains a configuration for a RIB identified
             by the 'name' key.

             Entries having the same key as a system-controlled entry
             in the list '/routing/ribs/rib' are used for
             configuring parameters of that entry.  Other entries
             define additional user-controlled RIBs.";
          leaf name {
            type string;
            description
              "The name of the RIB.

               For system-controlled entries, the value of this leaf
               must be the same as the name of the corresponding entry
               in the operational state.

               For user-controlled entries, an arbitrary name can be
               used.";
          }
          uses address-family {
            description
              "The address family of the system-controlled RIB.";



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          }

          leaf default-rib {
            if-feature "multiple-ribs";
            type boolean;
            default "true";
            config false;
            description
              "This flag has the value of 'true' if and only if the RIB
               is the default RIB for the given address family.

               By default, control-plane protocols place their routes
               in the default RIBs.";
          }
          container routes {
            config false;
            description
              "Current contents of the RIB.";
            list route {
              description
                "A RIB route entry.  This data node MUST be augmented
                 with information specific to routes of each address
                 family.";
              leaf route-preference {
                type route-preference;
                description
                  "This route attribute, also known as 'administrative
                   distance', allows for selecting the preferred route
                   among routes with the same destination prefix.  A
                   smaller value indicates a route that is
                   more preferred.";
              }
              container next-hop {
                description
                  "Route's next-hop attribute.";
                uses next-hop-state-content;
              }
              uses route-metadata;
            }
          }
          action active-route {
            description
              "Return the active RIB route that is used for the
               destination address.

               Address-family-specific modules MUST augment input
               parameters with a leaf named 'destination-address'.";
            output {



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              container route {
                description
                  "The active RIB route for the specified destination.

                   If no route exists in the RIB for the destination
                   address, no output is returned.

                   Address-family-specific modules MUST augment this
                   container with appropriate route contents.";
                container next-hop {
                  description
                    "Route's next-hop attribute.";
                  uses next-hop-state-content;
                }
                uses route-metadata;
              }
            }
          }
          leaf description {
            type string;
            description
              "Textual description of the RIB.";
          }
        }
      }
    }

    /*
     * The subsequent data nodes are obviated and obsoleted
     * by the Network Management Datastore Architecture
     * as described in RFC 8342.
     */
    container routing-state {
      config false;
      status obsolete;
      description
        "State data of the routing subsystem.";
      uses router-id {
        status obsolete;
        description
          "Global router ID.

           It may be either configured or assigned algorithmically by
           the implementation.";
      }
      container interfaces {
        status obsolete;
        description



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          "Network-layer interfaces used for routing.";
        leaf-list interface {
          type if:interface-state-ref;
          status obsolete;
          description
            "Each entry is a reference to the name of a configured
             network-layer interface.";
        }
      }
      container control-plane-protocols {
        status obsolete;
        description
          "Container for the list of routing protocol instances.";
        list control-plane-protocol {
          key "type name";
          status obsolete;
          description
            "State data of a control-plane protocol instance.

             An implementation MUST provide exactly one
             system-controlled instance of the 'direct'
             pseudo-protocol.  Instances of other control-plane
             protocols MAY be created by configuration.";
          leaf type {
            type identityref {
              base control-plane-protocol;
            }
            status obsolete;
            description
              "Type of the control-plane protocol.";
          }
          leaf name {
            type string;
            status obsolete;
            description
              "The name of the control-plane protocol instance.

               For system-controlled instances, this name is
               persistent, i.e., it SHOULD NOT change across
               reboots.";
          }
        }
      }
      container ribs {
        status obsolete;
        description
          "Container for RIBs.";
        list rib {



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          key "name";
          min-elements 1;
          status obsolete;
          description
            "Each entry represents a RIB identified by the 'name'
             key.  All routes in a RIB MUST belong to the same address
             family.

             An implementation SHOULD provide one system-controlled
             default RIB for each supported address family.";
          leaf name {
            type string;
            status obsolete;
            description
              "The name of the RIB.";
          }
          uses address-family {
            status obsolete;
            description
              "The address family of the RIB.";
          }
          leaf default-rib {
            if-feature "multiple-ribs";
            type boolean;
            default "true";
            status obsolete;
            description
              "This flag has the value of 'true' if and only if the
               RIB is the default RIB for the given address family.

               By default, control-plane protocols place their routes
               in the default RIBs.";
          }
          container routes {
            status obsolete;
            description
              "Current contents of the RIB.";
            list route {
              status obsolete;
              description
                "A RIB route entry.  This data node MUST be augmented
                 with information specific to routes of each address
                 family.";
              leaf route-preference {
                type route-preference;
                status obsolete;
                description
                  "This route attribute, also known as 'administrative



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                   distance', allows for selecting the preferred route
                   among routes with the same destination prefix.  A
                   smaller value indicates a route that is
                   more preferred.";
              }
              container next-hop {
                status obsolete;
                description
                  "Route's next-hop attribute.";
                uses next-hop-state-content {
                  status obsolete;
                  description
                    "Route's next-hop attribute operational state.";
                }
              }
              uses route-metadata {
                status obsolete;
                description
                  "Route metadata.";
              }
            }
          }
          action active-route {
            status obsolete;
            description
              "Return the active RIB route that is used for the
               destination address.

               Address-family-specific modules MUST augment input
               parameters with a leaf named 'destination-address'.";
            output {
              container route {
                status obsolete;
                description
                  "The active RIB route for the specified
                   destination.

                   If no route exists in the RIB for the destination
                   address, no output is returned.

                   Address-family-specific modules MUST augment this
                   container with appropriate route contents.";
                container next-hop {
                  status obsolete;
                  description
                    "Route's next-hop attribute.";
                  uses next-hop-state-content {
                    status obsolete;



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                    description
                      "Active route state data.";
                  }
                }
                uses route-metadata {
                  status obsolete;
                  description
                    "Active route metadata.";
                }
              }
            }
          }
        }
      }
    }
  }

  <CODE ENDS>

8.  IPv4 Unicast Routing Management YANG Module

  <CODE BEGINS> file "[email protected]"

  module ietf-ipv4-unicast-routing {
    yang-version "1.1";
    namespace
      "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing";
    prefix "v4ur";

    import ietf-routing {
      prefix "rt";
      description
        "An 'ietf-routing' module version that is compatible with
         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    import ietf-inet-types {
      prefix "inet";
    }
    organization
      "IETF NETMOD (Network Modeling) Working Group";
    contact
      "WG Web:   <https://datatracker.ietf.org/wg/netmod/>
       WG List:  <mailto:[email protected]>

       Editor:   Ladislav Lhotka
                 <mailto:[email protected]>



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                 Acee Lindem
                 <mailto:[email protected]>
                 Yingzhen Qu
                 <mailto:[email protected]>";

    description
      "This YANG module augments the 'ietf-routing' module with basic
       parameters for IPv4 unicast routing.  The model fully conforms
       to the Network Management Datastore Architecture (NMDA).

       Copyright (c) 2018 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 8349; see
       the RFC itself for full legal notices.";

    revision 2018-03-13 {
      description
        "Network Management Datastore Architecture (NMDA) revision.";
      reference
        "RFC 8349: A YANG Data Model for Routing Management
                   (NMDA Version)";
    }

    revision 2016-11-04 {
         description
           "Initial revision.";
         reference
           "RFC 8022: A YANG Data Model for Routing Management";
    }

    /* Identities */

    identity ipv4-unicast {
      base rt:ipv4;
      description
        "This identity represents the IPv4 unicast address family.";
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route" {
      when "derived-from-or-self(../../rt:address-family, "



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         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "This leaf augments an IPv4 unicast route.";
      leaf destination-prefix {
        type inet:ipv4-prefix;
        description
          "IPv4 destination prefix.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
          + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "Augments the 'simple-next-hop' case in IPv4 unicast routes.";
      leaf next-hop-address {
        type inet:ipv4-address;
        description
          "IPv4 address of the next hop.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
          + "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
          + "rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "This leaf augments the 'next-hop-list' case of IPv4 unicast
         routes.";
      leaf address {
        type inet:ipv4-address;
        description
          "IPv4 address of the next hop.";
      }
    }

    augment



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      "/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:input" {
      when "derived-from-or-self(../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast RIBs.";
      }
      description
        "This augment adds the input parameter of the 'active-route'
         action.";
      leaf destination-address {
        type inet:ipv4-address;
        description
          "IPv4 destination address.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route" {
      when "derived-from-or-self(../../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "This augment adds the destination prefix to the reply of the
         'active-route' action.";
      leaf destination-prefix {
        type inet:ipv4-prefix;
        description
          "IPv4 destination prefix.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
          + "rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "Augments the 'simple-next-hop' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv4-address;
        description
          "IPv4 address of the next hop.";



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      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
          + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family, "
         + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      description
        "Augments the 'next-hop-list' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv4-address;
        description
          "IPv4 address of the next hop.";
      }
    }

    augment "/rt:routing/rt:control-plane-protocols/"
          + "rt:control-plane-protocol/rt:static-routes" {
      description
        "This augment defines the 'static' pseudo-protocol
         with data specific to IPv4 unicast.";
      container ipv4 {
        description
          "Support for a 'static' pseudo-protocol instance
           consists of a list of routes.";
        list route {
          key "destination-prefix";
          description
            "A list of static routes.";
          leaf destination-prefix {
            type inet:ipv4-prefix;
            mandatory true;
            description
              "IPv4 destination prefix.";
          }
          leaf description {
            type string;
            description
              "Textual description of the route.";
          }
          container next-hop {
            description
              "Support for next-hop.";



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            uses rt:next-hop-content {
              augment "next-hop-options/simple-next-hop" {
                description
                  "Augments the 'simple-next-hop' case in IPv4 static
                   routes.";
                leaf next-hop-address {
                  type inet:ipv4-address;
                  description
                    "IPv4 address of the next hop.";
                }
              }
              augment "next-hop-options/next-hop-list/next-hop-list/"
                    + "next-hop" {
                description
                  "Augments the 'next-hop-list' case in IPv4 static
                   routes.";
                leaf next-hop-address {
                  type inet:ipv4-address;
                  description
                    "IPv4 address of the next hop.";
                }
              }
            }
          }
        }
      }
    }

    /*
     * The subsequent data nodes are obviated and obsoleted
     * by the Network Management Datastore Architecture
     * as described in RFC 8342.
     */
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" {
      when "derived-from-or-self(../../rt:address-family, "
           + "'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "This leaf augments an IPv4 unicast route.";
      leaf destination-prefix {
        type inet:ipv4-prefix;
        status obsolete;
        description
          "IPv4 destination prefix.";
      }



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    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/"
            + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
      when "derived-from-or-self(
              ../../../rt:address-family, 'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "Augments the 'simple-next-hop' case in IPv4 unicast routes.";
      leaf next-hop-address {
        type inet:ipv4-address;
        status obsolete;
        description
          "IPv4 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/"
            + "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
            + "rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family,
              'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "This leaf augments the 'next-hop-list' case of IPv4 unicast
         routes.";
      leaf address {
        type inet:ipv4-address;
        status obsolete;
        description
          "IPv4 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:input" {
      when "derived-from-or-self(../rt:address-family,
              'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast RIBs.";
      }
      status obsolete;
      description
        "This augment adds the input parameter of the 'active-route'
         action.";



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      leaf destination-address {
        type inet:ipv4-address;
        status obsolete;
        description
          "IPv4 destination address.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route" {
      when "derived-from-or-self(../../rt:address-family,
              'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "This augment adds the destination prefix to the reply of the
         'active-route' action.";
      leaf destination-prefix {
        type inet:ipv4-prefix;
        status obsolete;
        description
          "IPv4 destination prefix.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
            + "rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family,
              'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "Augments the 'simple-next-hop' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv4-address;
        status obsolete;
        description
          "IPv4 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
            + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family,



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              'v4ur:ipv4-unicast')" {
        description
          "This augment is valid only for IPv4 unicast.";
      }
      status obsolete;
      description
        "Augments the 'next-hop-list' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv4-address;
        status obsolete;
        description
          "IPv4 address of the next hop.";
      }
    }
  }

  <CODE ENDS>

9.  IPv6 Unicast Routing Management YANG Module

  <CODE BEGINS> file "[email protected]"

  module ietf-ipv6-unicast-routing {
    yang-version "1.1";
    namespace
      "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing";
    prefix "v6ur";

    import ietf-routing {
      prefix "rt";
      description
        "An 'ietf-routing' module version that is compatible with
         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    import ietf-inet-types {
      prefix "inet";
      description
        "An 'ietf-interfaces' module version that is compatible with
         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    include ietf-ipv6-router-advertisements {
      revision-date 2018-03-13;
    }



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    organization
      "IETF NETMOD (Network Modeling) Working Group";
    contact
      "WG Web:   <https://datatracker.ietf.org/wg/netmod/>
       WG List:  <mailto:[email protected]>

       Editor:   Ladislav Lhotka
                 <mailto:[email protected]>
                 Acee Lindem
                 <mailto:[email protected]>
                 Yingzhen Qu
                 <mailto:[email protected]>";

    description
      "This YANG module augments the 'ietf-routing' module with basic
       parameters for IPv6 unicast routing.  The model fully conforms
       to the Network Management Datastore Architecture (NMDA).

       Copyright (c) 2018 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 8349; see
       the RFC itself for full legal notices.";

    revision 2018-03-13 {
      description
        "Network Management Datastore Architecture (NMDA) revision.";
      reference
        "RFC 8349: A YANG Data Model for Routing Management
                   (NMDA Version)";
    }

    /* Identities */

    revision 2016-11-04 {
         description
           "Initial revision.";
         reference
           "RFC 8022: A YANG Data Model for Routing Management";
    }




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    identity ipv6-unicast {
      base rt:ipv6;
      description
        "This identity represents the IPv6 unicast address family.";
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route" {
      when "derived-from-or-self(../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      description
        "This leaf augments an IPv6 unicast route.";
      leaf destination-prefix {
        type inet:ipv6-prefix;
        description
          "IPv6 destination prefix.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
          + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      description
        "Augments the 'simple-next-hop' case in IPv6 unicast routes.";
      leaf next-hop-address {
        type inet:ipv6-address;
        description
          "IPv6 address of the next hop.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route/"
          + "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
          + "rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      description
        "This leaf augments the 'next-hop-list' case of IPv6 unicast
         routes.";



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      leaf address {
        type inet:ipv6-address;
        description
          "IPv6 address of the next hop.";
      }
    }

    augment
      "/rt:routing/rt:ribs/rt:rib/rt:active-route/rt:input" {
      when "derived-from-or-self(../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast RIBs.";
      }
      description
        "This augment adds the input parameter of the 'active-route'
         action.";
      leaf destination-address {
        type inet:ipv6-address;
        description
          "IPv6 destination address.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route" {
      when "derived-from-or-self(../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      description
        "This augment adds the destination prefix to the reply of the
         'active-route' action.";
      leaf destination-prefix {
        type inet:ipv6-prefix;
        description
          "IPv6 destination prefix.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
          + "rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";



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      }
      description
        "Augments the 'simple-next-hop' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv6-address;
        description
          "IPv6 address of the next hop.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
          + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family, "
         + "'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      description
        "Augments the 'next-hop-list' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv6-address;
        description
          "IPv6 address of the next hop.";
      }
    }

    /* Data node augmentations */

    augment "/rt:routing/rt:control-plane-protocols/"
          + "rt:control-plane-protocol/rt:static-routes" {
      description
        "This augment defines the 'static' pseudo-protocol
         with data specific to IPv6 unicast.";
      container ipv6 {
        description
          "Support for a 'static' pseudo-protocol instance
           consists of a list of routes.";
        list route {
          key "destination-prefix";
          description
            "A list of static routes.";
          leaf destination-prefix {
            type inet:ipv6-prefix;
            mandatory true;
            description



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              "IPv6 destination prefix.";
          }
          leaf description {
            type string;
            description
              "Textual description of the route.";
          }
          container next-hop {
            description
              "Next hop for the route.";
            uses rt:next-hop-content {
              augment "next-hop-options/simple-next-hop" {
                description
                  "Augments the 'simple-next-hop' case in IPv6 static
                   routes.";
                leaf next-hop-address {
                  type inet:ipv6-address;
                  description
                    "IPv6 address of the next hop.";
                }
              }
              augment "next-hop-options/next-hop-list/next-hop-list/"
                    + "next-hop" {
                description
                  "Augments the 'next-hop-list' case in IPv6 static
                   routes.";
                leaf next-hop-address {
                  type inet:ipv6-address;
                  description
                    "IPv6 address of the next hop.";
                }
              }
            }
          }
        }
      }
    }

    /*
     * The subsequent data nodes are obviated and obsoleted
     * by the Network Management Datastore Architecture
     * as described in RFC 8342.
     */
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" {
      when "derived-from-or-self(../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";



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      }
      status obsolete;
      description
        "This leaf augments an IPv6 unicast route.";
      leaf destination-prefix {
        type inet:ipv6-prefix;
        status obsolete;
        description
          "IPv6 destination prefix.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/"
            + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      status obsolete;
      description
        "Augments the 'simple-next-hop' case in IPv6 unicast routes.";
      leaf next-hop-address {
        type inet:ipv6-address;
        status obsolete;
        description
          "IPv6 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/"
            + "rt:next-hop/rt:next-hop-options/rt:next-hop-list/"
            + "rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      status obsolete;
      description
        "This leaf augments the 'next-hop-list' case of IPv6 unicast
         routes.";
      leaf address {
        type inet:ipv6-address;
        status obsolete;
        description
          "IPv6 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/"



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            + "rt:active-route/rt:input" {
      when "derived-from-or-self(../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast RIBs.";
      }
      status obsolete;
      description
        "This augment adds the input parameter of the 'active-route'
         action.";
      leaf destination-address {
        type inet:ipv6-address;
        status obsolete;
        description
          "IPv6 destination address.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route" {
      when "derived-from-or-self(../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      status obsolete;
      description
        "This augment adds the destination prefix to the reply of the
         'active-route' action.";
      leaf destination-prefix {
        type inet:ipv6-prefix;
        status obsolete;
        description
          "IPv6 destination prefix.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
            + "rt:simple-next-hop" {
      when "derived-from-or-self(../../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      status obsolete;
      description
        "Augments the 'simple-next-hop' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {



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        type inet:ipv6-address;
        status obsolete;
        description
          "IPv6 address of the next hop.";
      }
    }
    augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
            + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/"
            + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" {
      when "derived-from-or-self(../../../../../rt:address-family,
              'v6ur:ipv6-unicast')" {
        description
          "This augment is valid only for IPv6 unicast.";
      }
      status obsolete;
      description
        "Augments the 'next-hop-list' case in the reply to the
         'active-route' action.";
      leaf next-hop-address {
        type inet:ipv6-address;
        status obsolete;
        description
          "IPv6 address of the next hop.";
      }
    }
  }

  <CODE ENDS>

9.1.  IPv6 Router Advertisements Submodule

  <CODE BEGINS> file "[email protected]"

  submodule ietf-ipv6-router-advertisements {
    yang-version "1.1";

    belongs-to ietf-ipv6-unicast-routing {
      prefix "v6ur";
    }

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

    import ietf-interfaces {
      prefix "if";
      description
        "An 'ietf-interfaces' module version that is compatible with



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         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    import ietf-ip {
      prefix "ip";
      description
        "An 'ietf-ip' module version that is compatible with
         the Network Management Datastore Architecture (NMDA)
         is required.";
    }

    organization
      "IETF NETMOD (Network Modeling) Working Group";
    contact
      "WG Web:   <https://datatracker.ietf.org/wg/netmod/>
       WG List:  <mailto:[email protected]>

       Editor:   Ladislav Lhotka
                 <mailto:[email protected]>
                 Acee Lindem
                 <mailto:[email protected]>
                 Yingzhen Qu
                 <mailto:[email protected]>";

    description
      "This YANG module augments the 'ietf-ip' module with
       parameters for IPv6 Router Advertisements.  The model fully
       conforms to the Network Management Datastore
       Architecture (NMDA).

       Copyright (c) 2018 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 8349; see
       the RFC itself for full legal notices.";

    reference
      "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)";

    revision 2018-03-13 {



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      description
        "Network Management Datastore Architecture (NMDA) revision.";
      reference
        "RFC 8349: A YANG Data Model for Routing Management
                   (NMDA Version)";
    }

    revision 2016-11-04 {
         description
           "Initial revision.";
         reference
           "RFC 8022: A YANG Data Model for Routing Management";
    }

    augment "/if:interfaces/if:interface/ip:ipv6" {
      description
        "Augments interface configuration with parameters of IPv6
         Router Advertisements.";
      container ipv6-router-advertisements {
        description
          "Support for IPv6 Router Advertisements.";
        leaf send-advertisements {
          type boolean;
          default "false";
          description
            "A flag indicating whether or not the router sends
             periodic Router Advertisements and responds to
             Router Solicitations.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvSendAdvertisements";
        }
        leaf max-rtr-adv-interval {
          type uint16 {
            range "4..65535";
          }
          units "seconds";
          default "600";
          description
            "The maximum time allowed between sending unsolicited
             multicast Router Advertisements from the interface.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - MaxRtrAdvInterval";
        }
        leaf min-rtr-adv-interval {
          type uint16 {
            range "3..1350";



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          }
          units "seconds";
          must ". <= 0.75 * ../max-rtr-adv-interval" {
            description
              "The value MUST NOT be greater than 75% of
               'max-rtr-adv-interval'.";
          }
          description
            "The minimum time allowed between sending unsolicited
             multicast Router Advertisements from the interface.

             The default value to be used operationally if this
             leaf is not configured is determined as follows:

             - if max-rtr-adv-interval >= 9 seconds, the default
               value is 0.33 * max-rtr-adv-interval;

             - otherwise, it is 0.75 * max-rtr-adv-interval.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - MinRtrAdvInterval";
        }
        leaf managed-flag {
          type boolean;
          default "false";
          description
            "The value to be placed in the 'Managed address
             configuration' flag field in the Router
             Advertisement.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvManagedFlag";
        }
        leaf other-config-flag {
          type boolean;
          default "false";
          description
            "The value to be placed in the 'Other configuration'
             flag field in the Router Advertisement.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvOtherConfigFlag";
        }
        leaf link-mtu {
          type uint32;
          default "0";
          description
            "The value to be placed in MTU options sent by the



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             router.  A value of zero indicates that no MTU options
             are sent.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvLinkMTU";
        }
        leaf reachable-time {
          type uint32 {
            range "0..3600000";
          }
          units "milliseconds";
          default "0";
          description
            "The value to be placed in the Reachable Time field in
             the Router Advertisement messages sent by the router.
             A value of zero means unspecified (by this router).";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvReachableTime";
        }
        leaf retrans-timer {
          type uint32;
          units "milliseconds";
          default "0";
          description
            "The value to be placed in the Retrans Timer field in
             the Router Advertisement messages sent by the router.
             A value of zero means unspecified (by this router).";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvRetransTimer";
        }
        leaf cur-hop-limit {
          type uint8;
          description
            "The value to be placed in the Cur Hop Limit field in
             the Router Advertisement messages sent by the router.
             A value of zero means unspecified (by this router).

             If this parameter is not configured, the device SHOULD
             use the IANA-specified value for the default IPv4
             Time to Live (TTL) parameter that was in effect at the
             time of implementation.";
          reference
            "RFC 3232: Assigned Numbers: RFC 1700 is Replaced by
                       an On-line Database
             RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvCurHopLimit



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             IANA: IP Parameters
                   (https://www.iana.org/assignments/ip-parameters)";
        }
        leaf default-lifetime {
          type uint16 {
            range "0..65535";
          }
          units "seconds";
          description
            "The value to be placed in the Router Lifetime field of
             Router Advertisements sent from the interface, in
             seconds.  It MUST be either zero or between
             max-rtr-adv-interval and 9000 seconds.  A value of zero
             indicates that the router is not to be used as a
             default router.  These limits may be overridden by
             specific documents that describe how IPv6 operates over
             different link layers.

             If this parameter is not configured, the device SHOULD
             use a value of 3 * max-rtr-adv-interval.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvDefaultLifetime";
        }
        container prefix-list {
          description
            "Support for prefixes to be placed in Prefix
             Information options in Router Advertisement messages
             sent from the interface.

             Prefixes that are advertised by default but do not
             have their entries in the child 'prefix' list are
             advertised with the default values of all parameters.

             The link-local prefix SHOULD NOT be included in the
             list of advertised prefixes.";
          reference
            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                       - AdvPrefixList";
          list prefix {
            key "prefix-spec";
            description
              "Support for an advertised prefix entry.";
            leaf prefix-spec {
              type inet:ipv6-prefix;
              description
                "IPv6 address prefix.";
            }



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            choice control-adv-prefixes {
              default "advertise";
              description
                "Either (1) the prefix is explicitly removed from the
                 set of advertised prefixes or (2) the parameters with
                 which the prefix is advertised are specified (default
                 case).";
              leaf no-advertise {
                type empty;
                description
                  "The prefix will not be advertised.

                   This can be used for removing the prefix from
                   the default set of advertised prefixes.";
              }
              case advertise {
                leaf valid-lifetime {
                  type uint32;
                  units "seconds";
                  default "2592000";
                  description
                    "The value to be placed in the Valid Lifetime
                     in the Prefix Information option.  The
                     designated value of all 1's (0xffffffff)
                      represents infinity.";
                  reference
                    "RFC 4861: Neighbor Discovery for IP version 6
                               (IPv6) - AdvValidLifetime";
                }
                leaf on-link-flag {
                  type boolean;
                  default "true";
                  description
                    "The value to be placed in the on-link flag
                     ('L-bit') field in the Prefix Information
                     option.";
                  reference
                    "RFC 4861: Neighbor Discovery for IP version 6
                               (IPv6) - AdvOnLinkFlag";
                }
                leaf preferred-lifetime {
                  type uint32;
                  units "seconds";
                  must ". <= ../valid-lifetime" {
                    description
                      "This value MUST NOT be greater than
                       valid-lifetime.";
                  }



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                  default "604800";
                  description
                    "The value to be placed in the Preferred
                     Lifetime in the Prefix Information option.
                     The designated value of all 1's (0xffffffff)
                     represents infinity.";
                  reference
                    "RFC 4861: Neighbor Discovery for IP version 6
                               (IPv6) - AdvPreferredLifetime";
                }
                leaf autonomous-flag {
                  type boolean;
                  default "true";
                  description
                    "The value to be placed in the Autonomous Flag
                     field in the Prefix Information option.";
                  reference
                    "RFC 4861: Neighbor Discovery for IP version 6
                               (IPv6) - AdvAutonomousFlag";
                }
              }
            }
          }
        }
      }
    }

    /*
     * The subsequent data nodes are obviated and obsoleted
     * by the Network Management Datastore Architecture
     * as described in RFC 8342.
     */
    augment "/if:interfaces-state/if:interface/ip:ipv6" {
      status obsolete;
      description
        "Augments interface state data with parameters of IPv6
         Router Advertisements.";
      container ipv6-router-advertisements {
        status obsolete;
        description
          "Parameters of IPv6 Router Advertisements.";
        leaf send-advertisements {
          type boolean;
          status obsolete;
          description
            "A flag indicating whether or not the router sends
             periodic Router Advertisements and responds to
             Router Solicitations.";



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        }
        leaf max-rtr-adv-interval {
          type uint16 {
            range "4..1800";
          }
          units "seconds";
          status obsolete;
          description
            "The maximum time allowed between sending unsolicited
             multicast Router Advertisements from the interface.";
        }
        leaf min-rtr-adv-interval {
          type uint16 {
            range "3..1350";
          }
          units "seconds";
          status obsolete;
          description
            "The minimum time allowed between sending unsolicited
             multicast Router Advertisements from the interface.";
        }
        leaf managed-flag {
          type boolean;
          status obsolete;
          description
            "The value that is placed in the 'Managed address
             configuration' flag field in the Router Advertisement.";
        }
        leaf other-config-flag {
          type boolean;
          status obsolete;
          description
            "The value that is placed in the 'Other configuration' flag
             field in the Router Advertisement.";
        }
        leaf link-mtu {
          type uint32;
          status obsolete;
          description
            "The value that is placed in MTU options sent by the
             router.  A value of zero indicates that no MTU options
             are sent.";
        }
        leaf reachable-time {
          type uint32 {
            range "0..3600000";
          }
          units "milliseconds";



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          status obsolete;
          description
            "The value that is placed in the Reachable Time field in
             the Router Advertisement messages sent by the router.  A
             value of zero means unspecified (by this router).";
        }
        leaf retrans-timer {
          type uint32;
          units "milliseconds";
          status obsolete;
          description
            "The value that is placed in the Retrans Timer field in the
             Router Advertisement messages sent by the router.  A value
             of zero means unspecified (by this router).";
        }
        leaf cur-hop-limit {
          type uint8;
          status obsolete;
          description
            "The value that is placed in the Cur Hop Limit field in the
             Router Advertisement messages sent by the router.  A value
             of zero means unspecified (by this router).";
        }
        leaf default-lifetime {
          type uint16 {
            range "0..9000";
          }
          units "seconds";
          status obsolete;
          description
            "The value that is placed in the Router Lifetime field of
             Router Advertisements sent from the interface, in seconds.
             A value of zero indicates that the router is not to be
             used as a default router.";
        }
        container prefix-list {
          status obsolete;
          description
            "A list of prefixes that are placed in Prefix Information
             options in Router Advertisement messages sent from the
             interface.

             By default, these are all prefixes that the router
             advertises via routing protocols as being on-link for the
             interface from which the advertisement is sent.";
          list prefix {
            key "prefix-spec";
            status obsolete;



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            description
              "Advertised prefix entry and its parameters.";
            leaf prefix-spec {
              type inet:ipv6-prefix;
              status obsolete;
              description
                "IPv6 address prefix.";
            }
            leaf valid-lifetime {
              type uint32;
              units "seconds";
              status obsolete;
              description
                "The value that is placed in the Valid Lifetime in the
                 Prefix Information option.  The designated value of
                 all 1's (0xffffffff) represents infinity.

                 An implementation SHOULD keep this value constant in
                 consecutive advertisements, except when it is
                 explicitly changed in configuration.";
            }
            leaf on-link-flag {
              type boolean;
              status obsolete;
              description
                "The value that is placed in the on-link flag ('L-bit')
                 field in the Prefix Information option.";
            }
            leaf preferred-lifetime {
              type uint32;
              units "seconds";
              status obsolete;
              description
                "The value that is placed in the Preferred Lifetime in
                 the Prefix Information option, in seconds.  The
                 designated value of all 1's (0xffffffff) represents
                 infinity.

                 An implementation SHOULD keep this value constant in
                 consecutive advertisements, except when it is
                 explicitly changed in configuration.";
            }
            leaf autonomous-flag {
              type boolean;
              status obsolete;
              description
                "The value that is placed in the Autonomous Flag field
                 in the Prefix Information option.";



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            }
          }
        }
      }
    }
  }

  <CODE ENDS>

10.  IANA Considerations

  [RFC8022] registered the following namespace URIs in the "IETF XML
  Registry" [RFC3688].  IANA has updated the references to refer to
  this document.

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

  URI: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing
  Registrant Contact: The IESG.
  XML: N/A; the requested URI is an XML namespace.

  URI: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing
  Registrant Contact: The IESG.
  XML: N/A; the requested URI is an XML namespace.

  [RFC8022] registered the following YANG modules in the "YANG Module
  Names" registry [RFC6020].  IANA has updated (1) the modules per this
  document and (2) the references to refer to this document.

  Name:      ietf-routing
  Namespace: urn:ietf:params:xml:ns:yang:ietf-routing
  Prefix:    rt
  Reference: RFC 8349

  Name:      ietf-ipv4-unicast-routing
  Namespace: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing
  Prefix:    v4ur
  Reference: RFC 8349

  Name:      ietf-ipv6-unicast-routing
  Namespace: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing
  Prefix:    v6ur
  Reference: RFC 8349






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  This document registers the following YANG submodule in the "YANG
  Module Names" registry [RFC6020]:

  Name:      ietf-ipv6-router-advertisements
  Module:    ietf-ipv6-unicast-routing
  Reference: RFC 8349

11.  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
  [RFC5246].

  The NETCONF access control model [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 these YANG 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:

  /routing/control-plane-protocols/control-plane-protocol:  This list
     specifies the control-plane protocols configured on a device.

  /routing/ribs/rib:  This list specifies the RIBs configured for the
     device.

  Some of the readable data nodes in these YANG modules 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 are the subtrees and
  data nodes and their sensitivity/vulnerability:

  /routing/control-plane-protocols/control-plane-protocol:  This list
     specifies the control-plane protocols configured on a device.
     Refer to the control-plane models for a list of sensitive
     information.





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  /routing/ribs/rib:  This list specifies the RIBs and their contents
     for the device.  Access to this information may disclose the
     network topology and/or other information.

  Some of the RPC operations in this YANG module may be considered
  sensitive or vulnerable in some network environments.  It is thus
  important to control access to these operations.  These are the
  operations and their sensitivity/vulnerability:

  /routing/ribs/rib/active-route:  The output from this RPC operation
     returns the route that is being used for a specified destination.
     Access to this information may disclose the network topology or
     relationship (e.g., client/provider).  Additionally, the routes
     used by a network device may be used to mount a subsequent attack
     on traffic traversing the network device.

12.  References

12.1.  Normative References

  [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>.

  [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
             "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
             DOI 10.17487/RFC4861, September 2007,
             <https://www.rfc-editor.org/info/rfc4861>.

  [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
             (TLS) Protocol Version 1.2", RFC 5246,
             DOI 10.17487/RFC5246, August 2008,
             <https://www.rfc-editor.org/info/rfc5246>.

  [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>.



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  [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>.

  [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
             RFC 6991, DOI 10.17487/RFC6991, July 2013,
             <https://www.rfc-editor.org/info/rfc6991>.

  [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>.

  [RFC8022]  Lhotka, L. and A. Lindem, "A YANG Data Model for Routing
             Management", RFC 8022, DOI 10.17487/RFC8022,
             November 2016, <https://www.rfc-editor.org/info/rfc8022>.

  [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>.

  [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>.

  [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>.

  [RFC8343]  Bjorklund, M., "A YANG Data Model for Interface
             Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
             <https://www.rfc-editor.org/info/rfc8343>.

  [RFC8344]  Bjorklund, M., "A YANG Data Model for IP Management",
             RFC 8344, DOI 10.17487/RFC8344, March 2018,
             <https://www.rfc-editor.org/info/rfc8344>.









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  [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>.

12.2.  Informative References

  [RFC7224]  Bjorklund, M., "IANA Interface Type YANG Module",
             RFC 7224, DOI 10.17487/RFC7224, May 2014,
             <https://www.rfc-editor.org/info/rfc7224>.

  [RFC7895]  Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module
             Library", RFC 7895, DOI 10.17487/RFC7895, June 2016,
             <https://www.rfc-editor.org/info/rfc7895>.

  [RFC7951]  Lhotka, L., "JSON Encoding of Data Modeled with YANG",
             RFC 7951, DOI 10.17487/RFC7951, August 2016,
             <https://www.rfc-editor.org/info/rfc7951>.

  [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>.

  [YANG-Guidelines]
             Bierman, A., "Guidelines for Authors and Reviewers of YANG
             Data Model Documents", Work in Progress,
             draft-ietf-netmod-rfc6087bis-20, March 2018.






















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Appendix A.  The Complete Schema Tree

  This appendix presents the complete tree of the core routing data
  model.  See [RFC8340] for an explanation of the symbols used.  The
  data type of every leaf node is shown near the right end of the
  corresponding line.

  module: ietf-routing
    +--rw routing
    |  +--rw router-id?                 yang:dotted-quad
    |  +--ro interfaces
    |  |  +--ro interface*   if:interface-ref
    |  +--rw control-plane-protocols
    |  |  +--rw control-plane-protocol* [type name]
    |  |     +--rw type             identityref
    |  |     +--rw name             string
    |  |     +--rw description?     string
    |  |     +--rw static-routes
    |  |        +--rw v4ur:ipv4
    |  |        |  +--rw v4ur:route* [destination-prefix]
    |  |        |     +--rw v4ur:destination-prefix
    |  |        |     |       inet:ipv4-prefix
    |  |        |     +--rw v4ur:description?          string
    |  |        |     +--rw v4ur:next-hop
    |  |        |        +--rw (v4ur:next-hop-options)
    |  |        |           +--:(v4ur:simple-next-hop)
    |  |        |           |  +--rw v4ur:outgoing-interface?
    |  |        |           |  |       if:interface-ref
    |  |        |           |  +--rw v4ur:next-hop-address?
    |  |        |           |          inet:ipv4-address
    |  |        |           +--:(v4ur:special-next-hop)
    |  |        |           |  +--rw v4ur:special-next-hop?
    |  |        |           |          enumeration
    |  |        |           +--:(v4ur:next-hop-list)
    |  |        |              +--rw v4ur:next-hop-list
    |  |        |                 +--rw v4ur:next-hop* [index]
    |  |        |                    +--rw v4ur:index
    |  |        |                    |       string
    |  |        |                    +--rw v4ur:outgoing-interface?
    |  |        |                    |       if:interface-ref
    |  |        |                    +--rw v4ur:next-hop-address?
    |  |        |                            inet:ipv4-address
    |  |        +--rw v6ur:ipv6
    |  |           +--rw v6ur:route* [destination-prefix]
    |  |              +--rw v6ur:destination-prefix
    |  |              |       inet:ipv6-prefix
    |  |              +--rw v6ur:description?          string




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    |  |              +--rw v6ur:next-hop
    |  |                 +--rw (v6ur:next-hop-options)
    |  |                    +--:(v6ur:simple-next-hop)
    |  |                    |  +--rw v6ur:outgoing-interface?
    |  |                    |  |       if:interface-ref
    |  |                    |  +--rw v6ur:next-hop-address?
    |  |                    |          inet:ipv6-address
    |  |                    +--:(v6ur:special-next-hop)
    |  |                    |  +--rw v6ur:special-next-hop?
    |  |                    |          enumeration
    |  |                    +--:(v6ur:next-hop-list)
    |  |                       +--rw v6ur:next-hop-list
    |  |                          +--rw v6ur:next-hop* [index]
    |  |                             +--rw v6ur:index
    |  |                             |       string
    |  |                             +--rw v6ur:outgoing-interface?
    |  |                             |       if:interface-ref
    |  |                             +--rw v6ur:next-hop-address?
    |  |                                     inet:ipv6-address
    |  +--rw ribs
    |     +--rw rib* [name]
    |        +--rw name              string
    |        +--rw address-family    identityref
    |        +--ro default-rib?      boolean {multiple-ribs}?
    |        +--ro routes
    |        |  +--ro route*
    |        |     +--ro route-preference?          route-preference
    |        |     +--ro next-hop
    |        |     |  +--ro (next-hop-options)
    |        |     |     +--:(simple-next-hop)
    |        |     |     |  +--ro outgoing-interface?
    |        |     |     |  |       if:interface-ref
    |        |     |     |  +--ro v4ur:next-hop-address?
    |        |     |     |  |       inet:ipv4-address
    |        |     |     |  +--ro v6ur:next-hop-address?
    |        |     |     |          inet:ipv6-address
    |        |     |     +--:(special-next-hop)
    |        |     |     |  +--ro special-next-hop?        enumeration
    |        |     |     +--:(next-hop-list)
    |        |     |        +--ro next-hop-list
    |        |     |           +--ro next-hop*
    |        |     |              +--ro outgoing-interface?
    |        |     |              |       if:interface-ref
    |        |     |              +--ro v4ur:address?
    |        |     |              |       inet:ipv4-address
    |        |     |              +--ro v6ur:address?
    |        |     |                      inet:ipv6-address




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    |        |     +--ro source-protocol            identityref
    |        |     +--ro active?                    empty
    |        |     +--ro last-updated?              yang:date-and-time
    |        |     +--ro v4ur:destination-prefix?   inet:ipv4-prefix
    |        |     +--ro v6ur:destination-prefix?   inet:ipv6-prefix
    |        +---x active-route
    |        |  +---w input
    |        |  |  +---w v4ur:destination-address?   inet:ipv4-address
    |        |  |  +---w v6ur:destination-address?   inet:ipv6-address
    |        |  +--ro output
    |        |     +--ro route
    |        |        +--ro next-hop
    |        |        |  +--ro (next-hop-options)
    |        |        |     +--:(simple-next-hop)
    |        |        |     |  +--ro outgoing-interface?
    |        |        |     |  |       if:interface-ref
    |        |        |     |  +--ro v4ur:next-hop-address?
    |        |        |     |  |       inet:ipv4-address
    |        |        |     |  +--ro v6ur:next-hop-address?
    |        |        |     |          inet:ipv6-address
    |        |        |     +--:(special-next-hop)
    |        |        |     |  +--ro special-next-hop?
    |        |        |     |          enumeration
    |        |        |     +--:(next-hop-list)
    |        |        |        +--ro next-hop-list
    |        |        |           +--ro next-hop*
    |        |        |              +--ro outgoing-interface?
    |        |        |              |       if:interface-ref
    |        |        |              +--ro v4ur:next-hop-address?
    |        |        |              |       inet:ipv4-address
    |        |        |              +--ro v6ur:next-hop-address?
    |        |        |                      inet:ipv6-address
    |        |        +--ro source-protocol            identityref
    |        |        +--ro active?                    empty
    |        |        +--ro last-updated?
    |        |        |       yang:date-and-time
    |        |        +--ro v4ur:destination-prefix?
    |        |        |       inet:ipv4-prefix
    |        |        +--ro v6ur:destination-prefix?
    |        |                inet:ipv6-prefix
    |        +--rw description?      string
    o--ro routing-state
       o--ro router-id?                 yang:dotted-quad
       o--ro interfaces
       |  o--ro interface*   if:interface-state-ref






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       o--ro control-plane-protocols
       |  o--ro control-plane-protocol* [type name]
       |     o--ro type    identityref
       |     o--ro name    string
       o--ro ribs
          o--ro rib* [name]
             o--ro name              string
             o--ro address-family    identityref
             o--ro default-rib?      boolean {multiple-ribs}?
             o--ro routes
             |  o--ro route*
             |     o--ro route-preference?          route-preference
             |     o--ro next-hop
             |     |  o--ro (next-hop-options)
             |     |     o--:(simple-next-hop)
             |     |     |  o--ro outgoing-interface?
             |     |     |  |       if:interface-ref
             |     |     |  o--ro v4ur:next-hop-address?
             |     |     |  |       inet:ipv4-address
             |     |     |  o--ro v6ur:next-hop-address?
             |     |     |          inet:ipv6-address
             |     |     o--:(special-next-hop)
             |     |     |  o--ro special-next-hop?        enumeration
             |     |     o--:(next-hop-list)
             |     |        o--ro next-hop-list
             |     |           o--ro next-hop*
             |     |              o--ro outgoing-interface?
             |     |              |       if:interface-ref
             |     |              o--ro v4ur:address?
             |     |              |       inet:ipv4-address
             |     |              o--ro v6ur:address?
             |     |                      inet:ipv6-address
             |     o--ro source-protocol            identityref
             |     o--ro active?                    empty
             |     o--ro last-updated?              yang:date-and-time
             |     o--ro v4ur:destination-prefix?   inet:ipv4-prefix
             |     o--ro v6ur:destination-prefix?   inet:ipv6-prefix
             o---x active-route
                o---w input
                |  o---w v4ur:destination-address?   inet:ipv4-address
                |  o---w v6ur:destination-address?   inet:ipv6-address
                o--ro output









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                   o--ro route
                      o--ro next-hop
                      |  o--ro (next-hop-options)
                      |     o--:(simple-next-hop)
                      |     |  o--ro outgoing-interface?
                      |     |  |       if:interface-ref
                      |     |  o--ro v4ur:next-hop-address?
                      |     |  |       inet:ipv4-address
                      |     |  o--ro v6ur:next-hop-address?
                      |     |          inet:ipv6-address
                      |     o--:(special-next-hop)
                      |     |  o--ro special-next-hop?
                      |     |          enumeration
                      |     o--:(next-hop-list)
                      |        o--ro next-hop-list
                      |           o--ro next-hop*
                      |              o--ro outgoing-interface?
                      |              |       if:interface-ref
                      |              o--ro v4ur:next-hop-address?
                      |              |       inet:ipv4-address
                      |              o--ro v6ur:next-hop-address?
                      |                      inet:ipv6-address
                      o--ro source-protocol            identityref
                      o--ro active?                    empty
                      o--ro last-updated?
                      |       yang:date-and-time
                      o--ro v4ur:destination-prefix?
                      |       inet:ipv4-prefix
                      o--ro v6ur:destination-prefix?
                              inet:ipv6-prefix
  module: ietf-ipv6-unicast-routing
    augment /if:interfaces/if:interface/ip:ipv6:
      +--rw ipv6-router-advertisements
         +--rw send-advertisements?    boolean
         +--rw max-rtr-adv-interval?   uint16
         +--rw min-rtr-adv-interval?   uint16
         +--rw managed-flag?           boolean
         +--rw other-config-flag?      boolean
         +--rw link-mtu?               uint32
         +--rw reachable-time?         uint32
         +--rw retrans-timer?          uint32
         +--rw cur-hop-limit?          uint8
         +--rw default-lifetime?       uint16
         +--rw prefix-list
            +--rw prefix* [prefix-spec]
               +--rw prefix-spec           inet:ipv6-prefix





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               +--rw (control-adv-prefixes)?
                  +--:(no-advertise)
                  |  +--rw no-advertise?         empty
                  +--:(advertise)
                     +--rw valid-lifetime?       uint32
                     +--rw on-link-flag?         boolean
                     +--rw preferred-lifetime?   uint32
                     +--rw autonomous-flag?      boolean
    augment /if:interfaces-state/if:interface/ip:ipv6:
      o--ro ipv6-router-advertisements
         o--ro send-advertisements?    boolean
         o--ro max-rtr-adv-interval?   uint16
         o--ro min-rtr-adv-interval?   uint16
         o--ro managed-flag?           boolean
         o--ro other-config-flag?      boolean
         o--ro link-mtu?               uint32
         o--ro reachable-time?         uint32
         o--ro retrans-timer?          uint32
         o--ro cur-hop-limit?          uint8
         o--ro default-lifetime?       uint16
         o--ro prefix-list
            o--ro prefix* [prefix-spec]
               o--ro prefix-spec           inet:ipv6-prefix
               o--ro valid-lifetime?       uint32
               o--ro on-link-flag?         boolean
               o--ro preferred-lifetime?   uint32
               o--ro autonomous-flag?      boolean

Appendix B.  Minimum Implementation

  Some parts and options of the core routing model, such as
  user-defined RIBs, are intended only for advanced routers.  This
  appendix gives basic non-normative guidelines for implementing a bare
  minimum of available functions.  Such an implementation may be used
  for hosts or very simple routers.

  A minimum implementation does not support the "multiple-ribs"
  feature.  This means that a single system-controlled RIB is available
  for each supported address family -- IPv4, IPv6, or both.  These RIBs
  are also the default RIBs.  No user-controlled RIBs are allowed.

  In addition to the mandatory instance of the "direct"
  pseudo-protocol, a minimum implementation should support configuring
  instance(s) of the "static" pseudo-protocol.

  For hosts that are never intended to act as routers, the ability to
  turn on sending IPv6 Router Advertisements (Section 5.4) should be
  removed.



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  Platforms with severely constrained resources may use deviations for
  restricting the data model, e.g., limiting the number of "static"
  control-plane protocol instances.

Appendix C.  Example: Adding a New Control-Plane Protocol

  This appendix demonstrates how the core routing data model can be
  extended to support a new control-plane protocol.  The YANG module
  "example-rip" shown below is intended as an illustration rather than
  a real definition of a data model for the Routing Information
  Protocol (RIP).  For the sake of brevity, this module does not obey
  all the guidelines specified in [YANG-Guidelines].  See also
  Section 5.3.2.

  module example-rip {

    yang-version "1.1";
    namespace "http://example.com/rip";
    prefix "rip";

    import ietf-interfaces {
      prefix "if";
    }

    import ietf-routing {
      prefix "rt";
    }

    identity rip {
      base rt:routing-protocol;
      description
        "Identity for the Routing Information Protocol (RIP).";
    }

    typedef rip-metric {
      type uint8 {
        range "0..16";
      }
    }












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    grouping route-content {
      description
        "This grouping defines RIP-specific route attributes.";
      leaf metric {
        type rip-metric;
      }
      leaf tag {
        type uint16;
        default "0";
        description
          "This leaf may be used to carry additional information,
           e.g., an autonomous system (AS) number.";
      }
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:routes/rt:route" {
      when "derived-from-or-self(rt:source-protocol, 'rip:rip')" {
        description
          "This augment is only valid for a route whose source
           protocol is RIP.";
      }
      description
        "RIP-specific route attributes.";
      uses route-content;
    }

    augment "/rt:routing/rt:ribs/rt:rib/rt:active-route/"
          + "rt:output/rt:route" {
      description
        "RIP-specific route attributes in the output of an
         'active-route' RPC.";
      uses route-content;
    }

    augment "/rt:routing/rt:control-plane-protocols/"
          + "rt:control-plane-protocol" {
      when "derived-from-or-self(rt:type,'rip:rip')" {
        description
          "This augment is only valid for a routing protocol instance
           of type 'rip'.";
      }
      container rip {
        presence
          "RIP configuration";
        description
          "RIP instance configuration.";
        container interfaces {




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          description
            "Per-interface RIP configuration.";
          list interface {
            key "name";
            description
              "RIP is enabled on interfaces that have an entry in this
               list, unless 'enabled' is set to 'false' for that
               entry.";
            leaf name {
              type if:interface-ref;
            }
            leaf enabled {
              type boolean;
              default "true";
            }
            leaf metric {
              type rip-metric;
              default "1";
            }
          }
        }
        leaf update-interval {
          type uint8 {
            range "10..60";
          }
          units "seconds";
          default "30";
          description
            "Time interval between periodic updates.";
        }
      }
    }
  }


















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Appendix D.  Data Tree Example

  This section contains an example of an instance data tree from the
  operational state, in JSON encoding [RFC7951].  (This example
  includes "iana-if-type", which is defined in [RFC7224].)

  The data conforms to a data model that is defined by the following
  YANG library specification [RFC7895]:

   {
     "ietf-yang-library:modules-state": {
       "module-set-id": "c2e1f54169aa7f36e1a6e8d0865d441d3600f9c4",
       "module": [
         {
           "name": "ietf-routing",
           "revision": "2018-03-13",
           "feature": [
             "multiple-ribs",
             "router-id"
           ],
           "namespace": "urn:ietf:params:xml:ns:yang:ietf-routing",
           "conformance-type": "implement"
         },
         {
           "name": "ietf-ipv4-unicast-routing",
           "revision": "2018-03-13",
           "namespace":
             "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing",
           "conformance-type": "implement"
         },
         {
           "name": "ietf-ipv6-unicast-routing",
           "revision": "2018-03-13",
           "namespace":
             "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing",
           "conformance-type": "implement",
           "submodule": [
             {
               "name": "ietf-ipv6-router-advertisements",
               "revision": "2018-03-13"
             }
           ]
         },
         {
           "name": "ietf-interfaces",
           "revision": "2018-02-20",
           "namespace": "urn:ietf:params:xml:ns:yang:ietf-interfaces",
           "conformance-type": "implement"



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         },
         {
           "name": "ietf-inet-types",
           "namespace": "urn:ietf:params:xml:ns:yang:ietf-inet-types",
           "revision": "2013-07-15",
           "conformance-type": "import"
         },
         {
           "name": "ietf-yang-types",
           "namespace": "urn:ietf:params:xml:ns:yang:ietf-yang-types",
           "revision": "2013-07-15",
           "conformance-type": "import"
         },
         {
           "name": "iana-if-type",
           "namespace": "urn:ietf:params:xml:ns:yang:iana-if-type",
           "revision": "2014-05-08",
           "conformance-type": "implement"
         },
         {
           "name": "ietf-ip",
           "revision": "2018-02-22",
           "namespace": "urn:ietf:params:xml:ns:yang:ietf-ip",
           "conformance-type": "implement"
         }
       ]
     }
   }























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  A simple network setup as shown in Figure 2 is assumed: router "A"
  uses static default routes with the "ISP" router as the next hop.
  IPv6 Router Advertisements are configured only on the "eth1"
  interface and disabled on the upstream "eth0" interface.

                  +-----------------+
                  |                 |
                  |    Router ISP   |
                  |                 |
                  +--------+--------+
                           |2001:db8:0:1::2
                           |192.0.2.2
                           |
                           |
                           |2001:db8:0:1::1
                       eth0|192.0.2.1
                  +--------+--------+
                  |                 |
                  |     Router A    |
                  |                 |
                  +--------+--------+
                       eth1|198.51.100.1
                           |2001:db8:0:2::1
                           |

               Figure 2: Example of Network Configuration

  The instance data tree could then be as follows:

  {
    "ietf-interfaces:interfaces": {
      "interface": [
        {
          "name": "eth0",
          "type": "iana-if-type:ethernetCsmacd",
          "description": "Uplink to ISP.",
          "phys-address": "00:0C:42:E5:B1:E9",
          "oper-status": "up",
          "statistics": {
            "discontinuity-time": "2015-10-24T17:11:27+02:00"
          },
          "ietf-ip:ipv4": {
            "forwarding": true,
            "mtu": 1500,
            "address": [
              {
                "ip": "192.0.2.1",
                "prefix-length": 24



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              }
            ]
          },
          "ietf-ip:ipv6": {
            "forwarding": true,
            "mtu": 1500,
            "address": [
              {
                "ip": "2001:0db8:0:1::1",
                "prefix-length": 64
              }
            ],
            "autoconf": {
              "create-global-addresses": false
            },
            "ietf-ipv6-unicast-routing:ipv6-router-advertisements": {
              "send-advertisements": false
            }
          }
        },
        {
          "name": "eth1",
          "type": "iana-if-type:ethernetCsmacd",
          "description": "Interface to the internal network.",
          "phys-address": "00:0C:42:E5:B1:EA",
          "oper-status": "up",
          "statistics": {
            "discontinuity-time": "2015-10-24T17:11:29+02:00"
          },
          "ietf-ip:ipv4": {
            "forwarding": true,
            "mtu": 1500,
            "address": [
              {
                "ip": "198.51.100.1",
                "prefix-length": 24
              }
            ]
          },
          "ietf-ip:ipv6": {
            "forwarding": true,
            "mtu": 1500,
            "address": [
              {
                "ip": "2001:0db8:0:2::1",
                "prefix-length": 64
              }
            ],



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            "autoconf": {
              "create-global-addresses": false
            },
            "ietf-ipv6-unicast-routing:ipv6-router-advertisements": {
              "send-advertisements": true,
              "prefix-list": {
                "prefix": [
                  {
                    "prefix-spec": "2001:db8:0:2::/64"
                  }
                ]
              }
            }
          }
        }
      ]
    },

    "ietf-routing:routing": {
      "router-id": "192.0.2.1",
      "control-plane-protocols": {
        "control-plane-protocol": [
          {
            "type": "ietf-routing:static",
            "name": "st0",
            "description":
              "Static routing is used for the internal network.",
            "static-routes": {
              "ietf-ipv4-unicast-routing:ipv4": {
                "route": [
                  {
                    "destination-prefix": "0.0.0.0/0",
                    "next-hop": {
                      "next-hop-address": "192.0.2.2"
                    }
                  }
                ]
              },
              "ietf-ipv6-unicast-routing:ipv6": {
                "route": [
                  {
                    "destination-prefix": "::/0",
                    "next-hop": {
                      "next-hop-address": "2001:db8:0:1::2"
                    }
                  }
                ]
              }



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            }
          }
        ]
      },
      "ribs": {
        "rib": [
          {
            "name": "ipv4-master",
            "address-family":
              "ietf-ipv4-unicast-routing:ipv4-unicast",
            "default-rib": true,
            "routes": {
              "route": [
                {
                  "ietf-ipv4-unicast-routing:destination-prefix":
                    "192.0.2.1/24",
                  "next-hop": {
                    "outgoing-interface": "eth0"
                  },
                  "route-preference": 0,
                  "source-protocol": "ietf-routing:direct",
                  "last-updated": "2015-10-24T17:11:27+02:00"
                },
                {
                  "ietf-ipv4-unicast-routing:destination-prefix":
                    "198.51.100.0/24",
                  "next-hop": {
                    "outgoing-interface": "eth1"
                  },
                  "source-protocol": "ietf-routing:direct",
                  "route-preference": 0,
                  "last-updated": "2015-10-24T17:11:27+02:00"
                },
                {
                  "ietf-ipv4-unicast-routing:destination-prefix":
                    "0.0.0.0/0",
                  "source-protocol": "ietf-routing:static",
                  "route-preference": 5,
                  "next-hop": {
                    "ietf-ipv4-unicast-routing:next-hop-address":
                      "192.0.2.2"
                  },
                  "last-updated": "2015-10-24T18:02:45+02:00"
                }
              ]
            }
          },
          {



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            "name": "ipv6-master",
            "address-family":
              "ietf-ipv6-unicast-routing:ipv6-unicast",
            "default-rib": true,
            "routes": {
              "route": [
                {
                  "ietf-ipv6-unicast-routing:destination-prefix":
                    "2001:db8:0:1::/64",
                  "next-hop": {
                    "outgoing-interface": "eth0"
                  },
                  "source-protocol": "ietf-routing:direct",
                  "route-preference": 0,
                  "last-updated": "2015-10-24T17:11:27+02:00"
                },
                {
                  "ietf-ipv6-unicast-routing:destination-prefix":
                    "2001:db8:0:2::/64",
                  "next-hop": {
                    "outgoing-interface": "eth1"
                  },
                  "source-protocol": "ietf-routing:direct",
                  "route-preference": 0,
                  "last-updated": "2015-10-24T17:11:27+02:00"
                },
                {
                  "ietf-ipv6-unicast-routing:destination-prefix":
                    "::/0",
                  "next-hop": {
                    "ietf-ipv6-unicast-routing:next-hop-address":
                      "2001:db8:0:1::2"
                  },
                  "source-protocol": "ietf-routing:static",
                  "route-preference": 5,
                  "last-updated": "2015-10-24T18:02:45+02:00"
                }
              ]
            }
          }
        ]
      }
    }
  }







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Appendix E.  NETCONF Get Data Reply Example

  This section gives an example of an XML [W3C.REC-xml-20081126] reply
  to the NETCONF <get-data> request for <operational> for a device that
  implements the example data models above.

  <rpc-reply
   xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
   message-id="101">
   <data>
     <routing
       xmlns="urn:ietf:params:xml:ns:yang:ietf-routing"
       xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin">

       <router-id or:origin="or:intended">192.0.2.1</router-id>
       <control-plane-protocols or:origin="or:intended">
         <control-plane-protocol>
           <type>ietf-routing:static</type>
           <name>static-routing-protocol</name>
           <static-routes>
             <ietf-ipv4-unicast-routing:ipv4>
               <route>
                 <destination-prefix>0.0.0.0/0</destination-prefix>
                 <next-hop>
                   <next-hop-address>192.0.2.2</next-hop-address>
                 </next-hop>
               </route>
             </ietf-ipv4-unicast-routing:ipv4>
             <ietf-ipv6-unicast-routing:ipv6>
               <route>
                 <destination-prefix>::/0</destination-prefix>
                 <next-hop>
                   <next-hop-address>2001:db8:0:1::2</next-hop-address>
                 </next-hop>
               </route>
             </ietf-ipv6-unicast-routing:ipv6>
           </static-routes>
         </control-plane-protocol>
       </control-plane-protocols>

       <ribs>
         <rib or:origin="or:intended">
           <name>ipv4-master</name>
           <address-family>
             ietf-ipv4-unicast-routing:ipv4-unicast
           </address-family>
           <default-rib>true</default-rib>
           <routes>



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             <route>
               <ietf-ipv4-unicast-routing:destination-prefix>
                 192.0.2.1/24
               </ietf-ipv4-unicast-routing:destination-prefix>
               <next-hop>
                 <outgoing-interface>eth0</outgoing-interface>
               </next-hop>
               <route-preference>0</route-preference>
               <source-protocol>ietf-routing:direct</source-protocol>
               <last-updated>2015-10-24T17:11:27+02:00</last-updated>
             </route>
             <route>
               <ietf-ipv4-unicast-routing:destination-prefix>
                 198.51.100.0/24
               </ietf-ipv4-unicast-routing:destination-prefix>
               <next-hop>
                 <outgoing-interface>eth1</outgoing-interface>
               </next-hop>
               <route-preference>0</route-preference>
               <source-protocol>ietf-routing:direct</source-protocol>
               <last-updated>2015-10-24T17:11:27+02:00</last-updated>
             </route>
             <route>
               <ietf-ipv4-unicast-routing:destination-prefix>0.0.0.0/0
               </ietf-ipv4-unicast-routing:destination-prefix>
               <next-hop>
                 <ietf-ipv4-unicast-routing:next-hop-address>192.0.2.2
                 </ietf-ipv4-unicast-routing:next-hop-address>
               </next-hop>
               <route-preference>5</route-preference>
               <source-protocol>ietf-routing:static</source-protocol>
               <last-updated>2015-10-24T18:02:45+02:00</last-updated>
             </route>
           </routes>
         </rib>
         <rib or:origin="or:intended">
           <name>ipv6-master</name>
           <address-family>
             ietf-ipv6-unicast-routing:ipv6-unicast
           </address-family>
           <default-rib>true</default-rib>
           <routes>
             <route>
               <ietf-ipv6-unicast-routing:destination-prefix>
                 2001:db8:0:1::/64
               </ietf-ipv6-unicast-routing:destination-prefix>
               <next-hop>
                 <outgoing-interface>eth0</outgoing-interface>



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RFC 8349                 YANG Routing Management              March 2018


               </next-hop>
               <route-preference>0</route-preference>
               <source-protocol>ietf-routing:direct</source-protocol>
               <last-updated>2015-10-24T17:11:27+02:00</last-updated>
             </route>
             <route>
               <ietf-ipv6-unicast-routing:destination-prefix>
                 2001:db8:0:2::/64
               </ietf-ipv6-unicast-routing:destination-prefix>
               <next-hop>
                 <outgoing-interface>eth1</outgoing-interface>
               </next-hop>
               <route-preference>0</route-preference>
               <source-protocol>ietf-routing:direct</source-protocol>
               <last-updated>2015-10-24T17:11:27+02:00</last-updated>
             </route>
             <route>
               <ietf-ipv6-unicast-routing:destination-prefix>::/0
               </ietf-ipv6-unicast-routing:destination-prefix>
               <next-hop>
                 <ietf-ipv6-unicast-routing:next-hop-address>
                   2001:db8:0:1::2
                 </ietf-ipv6-unicast-routing:next-hop-address>
               </next-hop>
               <route-preference>5</route-preference>
               <source-protocol>ietf-routing:static</source-protocol>
               <last-updated>2015-10-24T18:02:45+02:00</last-updated>
             </route>
           </routes>
         </rib>
       </ribs>
     </routing>
   </data>
  </rpc-reply>

















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RFC 8349                 YANG Routing Management              March 2018


Acknowledgments

  The authors wish to thank Nitin Bahadur, Martin Bjorklund, Dean
  Bogdanovic, Joe Clarke, Francis Dupont, Jeff Haas, Joel Halpern,
  Wes Hardaker, Jia He, Sriganesh Kini, Suresh Krishnan,
  David Lamparter, Xiang Li, Stephane Litkowski, Andrew McGregor,
  Jan Medved, Thomas Morin, Tom Petch, Bruno Rijsman,
  Juergen Schoenwaelder, Phil Shafer, Dave Thaler, Vladimir Vassilev,
  Rob Wilton, Yi Yang, Derek Man-Kit Yeung, and Jeffrey Zhang for their
  helpful comments and suggestions.

Authors' Addresses

  Ladislav Lhotka
  CZ.NIC

  Email: [email protected]


  Acee Lindem
  Cisco Systems

  Email: [email protected]


  Yingzhen Qu
  Huawei
  2330 Central Expressway
  Santa Clara, CA  95050
  United States of America

  Email: [email protected]



















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