Network Working Group                                            X. Liu
Internet-Draft                                                 P. Sarda
Intended status: Standards Track                               Ericsson
Expires: February 3, August 2, 2016                                    V. Choudhary
                                                    Huawei Technologies
                                                         August 3, 2015
                                                       February 2, 2016

         A YANG Data Model for Routing Information Protocol (RIP)
                     draft-ietf-rtgwg-yang-rip-00.txt
                     draft-ietf-rtgwg-yang-rip-01.txt

Abstract

   This document describes a data model for the Routing Information
   Protocol (RIP). Both RIP version 2 and RIPng are covered.

Status of this Memo

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

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   Task Force (IETF), its areas, and its working groups.  Note that
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   This Internet-Draft will expire on January 1, 2015.

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   Copyright (c) 2015 2016 IETF Trust and the persons identified as the
   document authors. All rights reserved.

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   described in the Simplified BSD License.

Table of Contents

   1. Introduction...................................................2
      1.1. Terminology...............................................2
      1.2. Tree Diagrams.............................................3
   2. RIP YANG model overview........................................3
   3. RIP YANG module................................................7 module................................................8
   4. IANA Considerations...........................................28 Considerations...........................................37
   5. Security Considerations.......................................28 Considerations.......................................37
   6. References....................................................29 References....................................................37
      6.1. Normative References.....................................29 References.....................................37
      6.2. Informative References...................................29 References...................................38

1. Introduction

   This document introduces a YANG [RFC6020] data model for the Routing
   Information Protocol (RIP)[RFC2453][RFC2080]. RIP was designed to
   work as an Interior Gateway Protocol (IGP) in moderate-size
   Autonomous Systems (AS).

   This YANG model supports both RIP version 2 and RIPng. RIP version 2
   defined
   (defined in [RFC2453] [RFC2453]) supports IPv4. RIPng defined (defined in [RFC2080] [RFC2080])
   supports IPv6.

1.1. Terminology

   The keywords "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].

   The following terms are defined in [RFC6020] and are not redefined
   here:

      o  augment

      o  data model
      o  data node

1.2. Tree Diagrams

   A simplified graphical representation of the data model is used in
   this document.  The meaning of the symbols in these diagrams is as
   follows:

      o  Brackets "[" and "]" enclose list keys.

      o  Curly braces "{" and "}" contain names of optional features
         that make the corresponding node conditional.

      o  Abbreviations before data node names: "rw" means configuration
         (read-write), and "ro" means state data (read-only).

      o  Symbols after data node names: "?" means an optional node, "!"
         means a presence container, and "*" denotes a list and leaf-
         list.

      o  Parentheses enclose choice and case nodes, and case nodes are
         also marked with a colon (":").

      o  Ellipsis ("...") stands for contents of subtrees that are not
         shown.

2. RIP YANG model overview

   This document defines the YANG module "ietf-rip", which has the
   following structure:

   module: ietf-rip
   augment /rt:routing/rt:routing-instance/rt:routing-protocols
   /rt:routing-protocol: /rt:routing/rt:routing-instance/rt:routing-protocols/
   rt:routing-protocol:
      +--rw rip
         +--rw originate-default-route!
         |  +--rw route-map?   string route-policy?   route-policy-ref
         +--rw default-metric?               uint8
         +--rw distance?                     uint8
         +--rw flash-update-threshold? triggered-update-threshold?   uint8
         +--rw maximum-paths?                uint8
         +--rw output-delay?                 uint8
         +--rw distribute-list* [prefix-list-name [prefix-set-name direction]
         |  +--rw prefix-list-name    string prefix-set-name    prefix-set-ref
         |  +--rw direction          enumeration
         |  +--rw if-name?           if:interface-ref
         +--rw redistribute
         |  +--rw bgp* [asn]
         |  |  +--rw asn             inet:as-number
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw cg-nat!
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw connected!
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw ipsec!
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw isis* [instance]
         |  |  +--rw instance        leafref
         |  |  +--rw level?          enumeration
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw nat!
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw ospfv2* [instance]
         |  |  +--rw instance        leafref
         |  |  +--rw route-type?     ospf:route-type
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw ospfv3* [instance]
         |  |  +--rw instance        leafref
         |  |  +--rw route-type?     ospf:route-type
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw ripv2* [instance]
         |  |  +--rw instance        leafref
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw ripng* [instance]
         |  |  +--rw instance        leafref
         |  |  +--rw metric?         uint8
         |  |  +--rw route-policy?   route-policy-ref
         |  +--rw static!
         |     +--rw metric?         uint8
         |     +--rw route-policy?   route-policy-ref
         +--rw timers
         |  +--rw update-interval?     uint16
         |  +--rw invalid-interval?    uint16
         |  +--rw holddown-interval?   uint16
         |  +--rw flush-interval?      uint16
         +--rw interface* [interface]
            +--rw interface                  if:interface-ref
            +--rw authentication
            |  +--rw (auth-type-selection)?
            |     +--:(auth-key-chain)
            |     |  +--rw key-chain?          key-chain:key-chain-ref
            |     +--:(auth-key)
            |        +--rw key?                string
            |        +--rw crypto-algorithm
            |           +--rw (algorithm)?
            |              +--:(hmac-sha-1-12) {crypto-hmac-sha-1-12}?
            |              |  +--rw hmac-sha1-12?   empty
            |              +--:(md5)
            |              |  +--rw md5?            empty
            |              +--:(sha-1)
            |              |  +--rw sha-1?          empty
            |              +--:(hmac-sha-1)
            |              |  +--rw hmac-sha-1?     empty
            |              +--:(hmac-sha-256)
            |              |  +--rw hmac-sha-256?   empty
            |              +--:(hmac-sha-384)
            |              |  +--rw hmac-sha-384?   empty
            |              +--:(hmac-sha-512)
            |                 +--rw hmac-sha-512?   empty
            +--rw bfd?                       boolean bfd {bfd}?
            |  +--rw enabled?                    boolean
            |  +--rw local-multiplier?           multiplier
            |  +--rw (interval-config-type)?
            |     +--:(tx-rx-intervals)
            |     |  +--rw desired-min-tx-interval     uint32
            |     |  +--rw required-min-rx-interval    uint32
            |     +--:(single-interval)
            |        +--rw min-interval                uint32
            +--rw cost?                      uint8
            +--rw neighbors {neighbor-configuration}?
            |  +--rw neighbor* [address]
            |     +--rw address    inet:ip-address
            +--rw no-listen?                 empty
            +--rw no-supply?                 empty
            +--rw originate-default-route!
            |  +--rw route-map?   string route-policy?   route-policy-ref
            +--rw split-horizon?             enumeration
            +--rw summary-address
            |  +--rw address?   inet:ip-prefix
            |  +--rw metric?    uint8
            +--rw timers
               +--rw update-interval?     uint16
               +--rw invalid-interval?    uint16
               +--rw holddown-interval?   uint16
               +--rw flush-interval?      uint16
   augment /rt:routing-state/rt:routing-instance/rt:routing-protocols
   /rt:routing-protocol: /rt:routing-state/rt:routing-instance/rt:routing-protocols/
   rt:routing-protocol:
      +--ro rip
         +--ro originate-default-route!
         |  +--ro route-map?   string route-policy?   route-policy-ref
         +--ro default-metric?               uint8
         +--ro distance?                     uint8
         +--ro flash-update-threshold? triggered-update-threshold?   uint8
         +--ro maximum-paths?                uint8
         +--ro output-delay?                 uint8
         +--ro distribute-list* [prefix-list-name [prefix-set-name direction]
         |  +--ro prefix-list-name    string prefix-set-name    prefix-set-ref
         |  +--ro direction          enumeration
         |  +--ro if-name?           if:interface-ref
         +--ro next-flash-update? next-triggered-update?        uint32
         +--ro num-of-routes?                uint32
         +--ro routing-table-version?     uint32
         +--ro timers
         |  +--ro update-interval?     uint16
         |  +--ro invalid-interval?    uint16
         |  +--ro holddown-interval?   uint16
         |  +--ro flush-interval?      uint16
         +--ro interface* [interface]
         |  +--ro interface                  if:interface-ref
         |  +--ro oper-status?               enumeration
         |  +--ro cost?                      uint8
         |  +--ro listen?                    boolean
         |  +--ro next-full-update?          uint32
         |  +--ro originate-default-route?   boolean
         |  +--ro poison-reverse?            boolean
         |  +--ro split-horizon?             boolean
         |  +--ro supply?                    boolean
         |  +--ro valid-address?             boolean
         |  +--ro timers
         |  |  +--ro update-interval?     uint16
         |  |  +--ro invalid-interval?    uint16
         |  |  +--ro holddown-interval?   uint16
         |  |  +--ro flush-interval?      uint16
         |  +--ro statistics {interface-statistics}?
         |     +--ro discontinuity-time?   yang:date-and-time
         |     +--ro bad-packets-rcvd?     yang:counter32
         |     +--ro bad-routes-rcvd?      yang:counter32
         |     +--ro updates-sent?         yang:counter32
         +--ro ipv4
         |  +--ro neighbors
         |  |  +--ro neighbor* [ipv4-address]
         |  |     +--ro ipv4-address        inet:ipv4-address
         |  |     +--ro last-update?        yang:date-and-time
         |  |     +--ro bad-packets-rcvd?   yang:counter32
         |  |     +--ro bad-routes-rcvd?    yang:counter32
         |  +--ro routes
         |     +--ro route* [ipv4-prefix]
         |        +--ro ipv4-prefix                     inet:ipv4-prefix
         |        +--ro next-hop?               inet:ipv4-address                       inet:ipv4-
   address
         |        +--ro interface?                      if:interface-ref
         |        +--ro redistributed?                  boolean
         |        +--ro route-type?                     enumeration
         |        +--ro metric?                         uint8
         |        +--ro expire-time?                    uint16
         |        +--ro deleted?                        boolean
         |        +--ro holddown?                       boolean
         |        +--ro need-flash? need-triggered-update?          boolean
         |        +--ro need-download-to-rib? inactive?                       boolean
         |        +--ro inactive? flush-expire-before-holddown?   boolean
         |        +--ro next-hop-flags?         bits
         +--ro ipv6
         |  +--ro neighbors
         |  |  +--ro neighbor* [ipv6-address]
         |  |     +--ro ipv6-address        inet:ipv6-address
         |  |     +--ro last-update?        yang:date-and-time
         |  |     +--ro bad-packets-rcvd?   yang:counter32
         |  |     +--ro bad-routes-rcvd?    yang:counter32
         |  +--ro routes
         |     +--ro route* [ipv6-prefix]
         |        +--ro ipv6-prefix                     inet:ipv6-prefix
         |        +--ro next-hop?               inet:ipv6-address                       inet:ipv6-
   address
         |        +--ro interface?                      if:interface-ref
         |        +--ro redistributed?                  boolean
         |        +--ro route-type?                     enumeration
         |        +--ro metric?                         uint8
         |        +--ro expire-time?                    uint16
         |        +--ro deleted?                        boolean
         |        +--ro holddown?                       boolean
         |        +--ro need-flash?             boolean
         |        +--ro need-download-to-rib? need-triggered-update?          boolean
         |        +--ro inactive?                       boolean
         |        +--ro next-hop-flags?         bits flush-expire-before-holddown?   boolean
         +--ro statistics {global-statistics}?
            +--ro discontinuity-time?   yang:date-and-time
            +--ro requests-rcvd?        yang:counter32
            +--ro requests-sent?        yang:counter32
            +--ro responses-rcvd?       yang:counter32
            +--ro responses-sent?       yang:counter32
   rpcs:
      +---x clear-rip-route
         +--ro
         +---w input
            +--ro instance-name?   leafref
            +---w routing-instance?   rt:routing-instance-ref
            +---w rip-instance?       Leafref

3. RIP YANG module

   <CODE BEGINS> file "ietf-rip@2015-06-22.yang" "ietf-rip@2016-01-28.yang"
   module ietf-rip {
     namespace "urn:ietf:params:xml:ns:yang:ietf-rip";
     // replace with IANA namespace when assigned
     prefix rip;
     import ietf-inet-types {
       prefix "inet";
     }

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

     import ietf-interfaces {
       prefix "if";
     }

     import ietf-ip {
       prefix "ip";
     }

     import ietf-routing {
       prefix "rt";
     }

     import ietf-key-chain {
       prefix "key-chain";
     }

     import ietf-bfd {
       prefix "bfd";
     }

     import routing-policy {
       prefix "policy";
     }

     import ietf-ospf {
       prefix "ospf";
     }

     organization "TBD";
     contact "TBD";
     description
       "This YANG module defines a model for managing Routing
       Information Protocol (RIP), including RIP version 2 and RIPng.";

     revision 2015-06-22 2016-01-28 {
       description
         "Initial revision.";
       reference
         "RFC 2453: RIP Version 2.
          RFC 2080: RIPng for IPv6.
          RFC 1724: RIP Version 2 MIB Extension.";
     }

     /*
      * Features
      */
     feature global-statistics bfd {
       description
         "This feature indicates that the system supports collecting
         global statistic data."; BFD.";
     }

     feature interface-statistics bfd-protocol-parms {
       description
         "BFD protocol specific parameters support.";
     }

     feature global-statistics {
       description
         "This feature indicates that the system supports collecting
         per-interface
         global statistic data.";
     }

     feature bfd interface-statistics {
       description
         "This feature indicates that the system supports BFD."; collecting
         per-interface statistic data.";
     }

     feature neighbor-configuration {
       description
         "This feature indicates that the system supports
         neighbor configuration.";
     }
     /*
      * Typedefs
      */

     typedef prefix-set-ref {
       type leafref {
         path "/policy:routing-policy/policy:defined-sets/"
           + "policy:prefix-sets/policy:prefix-set/"
           + "policy:prefix-set-name";
       }
       description
         "A type for a reference to a prefix list.";
     }

     typedef route-policy-ref {
       type leafref {
         path "/policy:routing-policy/policy:policy-definitions/"
           + "policy:policy-definition/policy:name";
       }
       description
         "A type for a reference to a route policy.";
     }

     /*
      * Identities
      */

     identity rip {
       base "rt:routing-protocol";
       description "Identity for the RIP routing protocol.";
     }

     identity ripv2 {
       base "rip:rip";
       description "RIPv2";
     }

     identity ripng {
       base "rip:rip";
       description "RIPng";
     }

     /*
      * Groupings
      */
     /*
      * Groupings
      */

     grouping originate-default-route-container {
       description
         "Container for setting of originating default route.";
       container originate-default-route {
         presence "Present if originating default route is enabled.";
         description
           "Injects the default route into the RIP or RIPng
           instance.";
         leaf route-policy {
           type route-policy-ref;
           description
             "The conditions of the route policy are applied to the
   default
             route.";
         }
       }
     }

     grouping redistribute-container {
       description
         "Container of redistribute attributes.";

       container redistribute {
         description
           "Redistributes routes learned from other routing protocols
            into the RIP routing instance.";
         list bgp {
           key "asn";
           description
             "Redistributes routes from the specified BGP autonomous
              system (AS) into the RIP routing instance.";
           leaf asn {
             type inet:as-number;
             description
               "BFP autonomous system (AS) number.";
           }
           uses redistribute-route-policy-attributes;
         }
         container cg-nat {
           presence
             "Present if Carrier Grade Network Address Translation
             (CGNAT) routes are redistributed.";
           description
             "Carrier Grade Network Address Translation (CGNAT)
             routes.";
           uses redistribute-route-policy-attributes;
         }
         container connected {
           presence
             "Present if directly attached network routes are
             redistributed.";
           description
             "Redistributes directly attached networks into the RIP
             routing instance.";
           uses redistribute-route-policy-attributes;
         }
         container ipsec {
           presence
             "Present if IP security routing instance routes
             are redistributed.";
           description
             "Redistributes routes from the IP security routing
             instance into the RIP routing instance.";
           uses redistribute-route-policy-attributes;
         }
         list isis {
           key "instance";
           description
             "Redistributes ISIS routes.";
           leaf instance {
             type leafref {
               path "../../../../../rt:routing-protocol/rt:name";
             }
             must "../../../../../rt:routing-protocol"
               + "[rt:name = current()]/type = 'isis'" {
               description
                 "The type of the routing protocol must be 'isis'";

             }
             description
               "Redistributes routes from the specified IS-IS routing
               instance into the RIP routing instance.";
           }
           leaf level {
             type enumeration {
               enum 1 {
                 description "ISIS level 1 routes.";
               }
               enum 2 {
                 description "ISIS level 1 routes.";
               }
               enum 1-2 {
                 description "ISIS level 1-2 routes.";
               }
             }
             description
               "ISIS level.";
           }
           uses redistribute-route-policy-attributes;
         }
         container nat {
           presence
             "Present if Network Address Translation (NAT) routes
             are redistributed.";
           description
             "Redistributes Network Address Translation (NAT)
             routes into the RIP routing instance.";
           uses redistribute-route-policy-attributes;
         }
         list ospfv2 {
           when "../../../rt:type = 'rip:ripv2'" {
             description
               "Applicable to RIPv2.";
           }
           key "instance";
           description
             "Redistributes routes from the specified OSPF routing
             instance into the RIP routing instance.";
           leaf instance {
             type leafref {
               path "../../../../../rt:routing-protocol/rt:name";
             }
             must "../../../../../rt:routing-protocol"
               + "[rt:name = current()]/type = 'ospfv2'" {
               description
                 "The type of the routing protocol must be 'ospfv2'";
             }
             description
               "OSPF instance ID. Redistributes routes from the
               specified OSPF routing instance into the RIP routing
               instance. ";
           }
           leaf route-type {
             type ospf:route-type;
             description
               "Redistributes only those OSPF routes matching the
               specified route type into the RIP routing instance.";
           }
           uses redistribute-route-policy-attributes;
         }
         list ospfv3 {
           when "../../../rt:type = 'rip:ripng'" {
             description
               "Applicable to RIPng.";
           }
           key "instance";
           description
             "Redistributes routes from the specified OSPF routing
             instance into the RIP routing instance.";
           leaf instance {
             type leafref {
               path "../../../../../rt:routing-protocol/rt:name";
             }
             must "../../../../../rt:routing-protocol"
               + "[rt:name = current()]/type = 'ospfv3'" {
               description
                 "The type of the routing protocol must be 'ospfv3'";
             }
             description
               "OSPF instance ID. Redistributes routes from the
               specified OSPF routing instance into the RIP routing
               instance. ";
           }
           leaf route-type {
             type ospf:route-type;
             description
               "Redistributes only those OSPF routes matching the
               specified route type into the RIP routing instance.";
           }
           uses redistribute-route-policy-attributes;
         }
         list ripv2 {
           when "../../../rt:type = 'rip:ripv2'" {
             description
               "Applicable to RIPv2.";
           }
           key "instance";
           description
             "Redistributes routes from another RIP routing instance
             into the current RIP routing instance.";
           leaf instance {
             type leafref {
               path "../../../../../rt:routing-protocol/rt:name";
             }
             must "../../../../../rt:routing-protocol"
               + "[rt:name = current()]/type = 'ripv2'" {
               description
                 "The type of the routing protocol must be 'ripv2'";
             }
             description
               "Redistributes routes from the specified RIP routing
               instance into the RIP routing instance.";
           }
           uses redistribute-route-policy-attributes;
         }
         list ripng {
           when "../../../rt:type = 'rip:ripng'" {
             description
               "Applicable to RIPng.";
           }
           key "instance";
           description
             "Redistributes routes from another RIPng routing instance
             into the current RIPng routing instance.";
           leaf instance {
             type leafref {
               path "../../../../../rt:routing-protocol/rt:name";
             }
             must "../../../../../rt:routing-protocol"
               + "[rt:name = current()]/type = 'ripng'" {
               description
                 "The type of the routing protocol must be 'ripng'";
             }
             description
               "Redistributes routes from the specified RIPng routing
               instance into the RIPng routing instance.";
           }
           uses redistribute-route-policy-attributes;
         }
         container static {
           presence "Present if redistributing static routes.";
           description
             "Redistributes static routes into the RIP routing
             instance.";
           uses redistribute-route-policy-attributes;
         }
       } // redistribute
     } // redistribute-container

     grouping originate-default-route-container redistribute-route-policy-attributes {
       description
         "Container
         "Attributes for setting of originating default route.";
       container originate-default-route {
         presence "Present if originating default redistributing a route is enabled."; policy.";
       leaf metric {
         type uint8 {
           range 0..16;
         }
         description
           "Injects
           "Metric used for the default route into redistributed route. If a metric is
           not specified, the metric configured with the
           default-metric attribute in RIP or RIPng
           instance."; router configuration is
           used. If the default-metric attribute has not been
           configured, the default metric for redistributed routes
           is 0.";
       }
       leaf route-map route-policy {
         type string; route-policy-ref;
         description
             "The
           "Applies the conditions of the specified route map are applied policy to
           routes that are redistributed into the default
             route.";
         } RIP routing
           instance.";
       }
     } // redistribute-route-policy-attributes

     grouping timers-container {
       description
         "Container for settings of basic timers";
       container timers {
         must "invalid-interval >= (update-interval * 3)" {
           description
             "invalid-interval must be at least three times the value
             for the update-interval argument.";
         }
         must "flush-interval > invalid-interval" {
           description
             "flush-interval must be larger than the value for the
             invalid-interval argument";
         }
         description
           "Timers for the specified RIP or RIPng instance or
           interface.";
         leaf update-interval {
           type uint16 {
             range  1..32767;
           }
           units seconds;
           default 30;
           description
             "Interval at which RIP or RIPng updates are sent.";
         }
         leaf invalid-interval {
           type uint16 {
             range 1..32767;
           }
           units seconds;
           default 180;
           description
             "Interval before a route is declared invalid after no
             updates are received. This value is at least three times
             the value for the update-interval argument.";
         }
         leaf holddown-interval {
           type uint16 {
             range 1..32767;
           }
           units seconds;
           default 180;
           description
             "Interval before better routes are released.";
         }
         leaf flush-interval {
           type uint16 {
             range 1..32767;
           }
           units seconds;
           default 240;
           description
             "Interval before a route is flushed from the routing
             table. This value must be larger than the value for the
             invalid-interval argument.";
         }
       } // timers
     }

     grouping global-attributes {
       description
         "Global configuration and state attributes.";
       uses originate-default-route-container;

       leaf default-metric {
         type uint8 {
           range 0..16;
         }
         default 0;
         description
           "Set the default metric.";
       }

       leaf distance {
         type uint8 {
           range 1..255;
         }
         default 120;
         description
           "The administrative distance of the RIP or RIPng for the
           current RIP or RIPng instance.";
       }

       leaf flash-update-threshold triggered-update-threshold {
         type uint8 {
           range 1..30;
         }
         units seconds;
         default 5;
         description
           "The minimum interval between consecutive RIP
           "This attribute is used to suppress triggered updates.
           When the arrival of a regularly scheduled update matches the
           number of seconds or RIPng
           flash updates."; is less than the number seconds
           configured with this attribute, the triggered update is
           suppressed.";
       }

       leaf maximum-paths {
         type uint8 {
           range 1..16;
         }
         default 8;
         description
           "The number of multiple equal-cost RIP or RIPng routes
           that can be used as the best paths for balancing the load
           of outgoing traffic packets.";
       }

       leaf output-delay {
         type uint8 {
           range 1..50;

         }
         units milliseconds;
         description
           "A delay time between packets sent in multipacket
           RIP or RIPng updates.";
       }
     } // global-attributes

     grouping distribute-lists {
       description
         "Grouping for distribute lists.";
       list distribute-list {
         key "prefix-list-name "prefix-set-name direction";
         description
           "List of distribute-lists, which are used to filter in-coming
           or out-going routing updates.";

         leaf prefix-list-name prefix-set-name {
           type string; prefix-set-ref;
           description
             "Reference to a prefix list to be applied to RIP or
             RIPng packets.";
         }

         leaf direction {
           type enumeration {
             enum "in" {
               description
                 "Apply the distribute-list to in-coming routes.";
             }
             enum "out" {
               description
                 "Apply the distribute-list to out-going routes.";
             }
           }
           description
             "Direction of the routing updates.";
         }

         leaf if-name {
           type if:interface-ref;
           description
             "Reference to an interface to which the prefix list is
             applied.";
         }
       }
     } // distribute-lists

     grouping route-attributes {
       description
         "Grouping for route attributes.";
       leaf redistributed {
         type boolean;
         description
           "Redistributed routes";
       }

       leaf route-type {
         type enumeration {
           enum connected {
             description "Connected route.";
           }
           enum external {
             description "External route.";
           }
           enum external-backup {
             description "External backup route.";
           }
           enum rip {
             description "RIP route.";
           }
         }
         description
           "Route type.";
       }
       leaf metric {
         type uint8 {
           range 0..16;
         }
         description "Route metric.";
       }
       leaf expire-time {
         type uint16;
         description "Expiration time.";
       }
       leaf deleted {
         type boolean;
         description "Deleted route.";
       }
       leaf holddown {
         type boolean;
         description "Holddown route.";
       }
       leaf need-flash {
         type boolean;
         description "The route needs flash.";
       }
       leaf need-download-to-rib need-triggered-update {
         type boolean;
         description "The route needs to be downloaded to rib."; triggered update.";
       }
       leaf inactive {
         type boolean;
         description "The route is inactive.";
       }
       leaf next-hop-flags {
         type bits {
           bit withdrawn-from-rib {
             description "The route is withdrawn from rib.";
           }
           bit holddown {
             description "The route is holddown.";
           }
           bit flush-expire-before-holddown {
         type boolean;
         description
           "The flush timer expired before holddown time.";
       }
     }
         description "The next hop properties of the route.";
       }
     } // route-attribute

     /*
      * Configuration data nodes
      */

     augment "/rt:routing/rt:routing-instance/rt:routing-protocols/"
       + "rt:routing-protocol" {
       when "rt:type = 'rip:ripv2' or rt:type = 'rip:ripng'" {
         description
           "This augment is only valid for a routing protocol instance
           of RIP (type 'ripv2' or 'ripng').";
       }
       description "RIP augmentation.";

       container rip {
         description
           "RIP configuration data.";

         uses global-attributes;
         uses distribute-lists;
         uses redistribute-container;
         uses timers-container;

         list interface {
           key "interface";
           description
             "List of RIP interfaces.";
           leaf interface {
             type if:interface-ref;
             must "(../../../rt:type = 'rip:ripv2' and "
               + "/if:interfaces/if:interface[name=current()]/"
               + "ip:ipv4) or "
               + "(../../../rt:type = 'rip:ripng' and "
               + "/if:interfaces/if:interface[name=current()]/"
               + "ip:ipv6)" {
               error-message "Invalid interface type.";
               description
                 "RIPv2 can be enabled on IPv4 interfae, and
                 RIPng can be enabled on IPv6 interface.";
             }
             description
               "Enable RIP on this interface.";
           }

           container authentication {
             when "../../../rt:type = 'rip:ripv2'" {
               description "Only applicable to RIPv2.";
             }
             description
               "Enables authentication and specifies the authentication
               scheme for the RIP interface";
             choice auth-type-selection {
               description
                 "Specify the authentication scheme.
                 The use of the key-chain reference here is:
                 1) Designed to align with other proposed protocol
                 models.

                 2) Not finalized, pending resolution of alignment with
                 the RFC published KeyTables information model.";
               case auth-key-chain {
                 leaf key-chain {
                   type key-chain:key-chain-ref;
                   description
                     "key-chain name";
                 }
               }
               case auth-key {
                 leaf key {
                   type string;
                   description
                     "Key string in ASCII format.";
                 }
                 container crypto-algorithm {
                   uses key-chain:crypto-algorithm-types;
                   description
                     "Cryptographic algorithm associated with key.";

                 }
               }
             }
           }

           leaf

           container bfd {
             if-feature bfd;
             description "BFD operation.";
             leaf enabled {
               type boolean;
               description
               "Enable/disable bfd.";
                 "True if BFD is enabled for the interface.";
             }
             uses bfd:bfd-grouping-base-cfg-parms {
               if-feature bfd-protocol-parms;
             }
           }

           leaf cost {
             type uint8 {
               range  1..16;

             }
             default 1;
             description
               "Interface cost.";
           }

           container neighbors {
             if-feature neighbor-configuration;
             description
               "Specifies the RIP neighbors. Useful for a non-broadcast
               multiple access (NBMA) network.";
             list neighbor {
               key "address";
               description
                 "Specify a RIP neighbor on a non-broadcast network.";
               leaf address {
                 type inet:ip-address;
                 description "Neighbor IP address.";
               }
             }
           }

           leaf no-listen {
             type empty;
             description
               "Disable the specified interface to receive (listen to)
               and process RIP or RIPng packets.";
           }

           leaf no-supply {
             type empty;
             description
               "Disables sending of RIP or RIPng packets on the
               specified interface.";
           }

           uses originate-default-route-container;

           leaf split-horizon {
             type enumeration {
               enum simple {
                 description
                   "Enables simple split-horizon processing.";
               }
               enum poison {
                 description
                   "Enables split-horizon processing with poison
                   reverse.";
               }
             }
             default simple;
             description
               "Enables RIP or RIPng split-horizon processing on the
               specified interface.";
           }

           container summary-address {
             description
               "Summarizes information about RIP or RIPng routes sent
               over the specified interface in RIP or RIPng update
               packets.";
             leaf address {
               type inet:ip-prefix;
               description
                 "IPv4 address, in the form A.B.C.D, and the prefix
                 length, separated by the slash (/) character;
                 or IPv6 address, in the form A:B:C:D:E:F:G:H, and the
                 prefix length, separated by the slash (/) character.";
             }
             leaf metric {
               type uint8 {
                 range 0..16;
               }
               description
                 "Metric used for the route. If this attribute is not
                 used, the value set through the default-metric
                 attribute in RIP or RIPng router configuration is
                 used for the route. ";
             }
           }

           uses timers-container;

         } // interface
       } // container rip
     }

     /*
      * Operational state data nodes
      */

     augment "/rt:routing-state/rt:routing-instance/"
       + "rt:routing-protocols/rt:routing-protocol" {
       when "rt:type = 'rip:ripv2' or rt:type = 'rip:ripng'"  {
         description
           "This augment is only valid for a routing protocol instance
           of type 'ripv2' or 'ripng'.";
       }
       description
         "RIP state.";
       container rip {
         description "RIP operational state.";

         uses global-attributes;
         uses distribute-lists;

         leaf next-flash-update next-triggered-update {
           type uint32;
           description
             "Next flash triggered update.";
         }
         leaf num-of-routes {
           type uint32;
           description
             "The number of routes.";
         }
         leaf routing-table-version {
           type uint32;
           description
             "Routing table version.";
         }

         uses timers-container;

         list interface {
           key "interface";
           description
             "List of RIP interfaces.";
           leaf interface {
             type if:interface-ref;
             description
               "Enable RIP on this interface.";
           }
           leaf oper-status {
             type enumeration {
               enum up {
                 description
                   "RIPv2 or RIPng is operational on this interface.";
               }
               enum down {
                 description
                   "RIPv2 or RIPng is not operational on this
                   interface.";
               }
             }
             description
               "Operational state.";
           }
           leaf cost {
             type uint8 {
               range  1..16;
             }
             default 1;
             description
               "Interface cost.";
           }
           leaf listen {
             type boolean;
             description
               "The interface is enabled to receive (listen to)
               and process RIP or RIPng packets.";
           }
           leaf next-full-update {
             type uint32;
             description
               "Next full update time.";
           }
           leaf originate-default-route {
             type boolean;
             description
               "'true' if originating default route is enabled.";
           }
           leaf poison-reverse {
             type boolean;
             description
               "'true' if Split Horizon with Poisoned Reverse is
               enabled.";
           }
           leaf split-horizon {
             type boolean;
             description
               "'true' if Split Horizon processing is enabled.";
           }
           leaf supply {
             type boolean;
             description
               "The interface is enabled to supply (send) RIP or RIPng
               packets.";
           }
           leaf valid-address {
             type boolean;
             description
               "The interface has a valid address.";
           }
           uses timers-container;

           container statistics {
             if-feature interface-statistics;
             description
               "Interface statistic counters.";
             leaf discontinuity-time {
               type yang:date-and-time;
               description
                 "The time on the most recent occasion at which any one
                 or more of the statistic counters suffered a
                 discontinuity. If no such discontinuities have occurred
                 since the last re-initialization of the local
                 management subsystem, then this node contains the time
                 the local management subsystem re-initialized itself.";
             }
             leaf bad-packets-rcvd {
               type yang:counter32;
               description
                 "The number of RIP invalid packets received by
                 the RIP process which were subsequently discarded
                 for any reason (e.g. a version 0 packet, or an
                 unknown command type).";
             }
             leaf bad-routes-rcvd {
               type yang:counter32;
               description
                 "The number of routes, in valid RIP packets,
                 which were ignored for any reason (e.g. unknown
                 address family, or invalid metric).";
             }
             leaf updates-sent {
               type yang:counter32;
               description
                 "The number of triggered RIP updates actually
                 sent on this interface.  This explicitly does
                 NOT include full updates sent containing new
                 information.";
             }
           }
         } // interface

         container ipv4 {
           when "../../rt:type = 'rip:ripv2'" {
             description
               "IPv4 address family is supported by RIPv2.";
           }
           description
             "IPv4 address family information.";
           container neighbors {
             description
               "IPv4 neighbor information.";
             list neighbor {
               key "ipv4-address";
               description
                 "A RIPv2 RIP neighbor.";

               leaf ipv4-address {
                 type inet:ipv4-address;
                 description
                   "IP address that a RIP neighbor is using as its
                   source address.";
               }
               leaf last-update {
                 type yang:date-and-time;
                 description
                   "The time when the most recent RIP update was
                   received from this neighbor.";
               }
               leaf bad-packets-rcvd {
                 type yang:counter32;
                 description
                   "The number of RIP invalid packets received from
                   this neighbor which were subsequently discarded
                   for any reason (e.g. a version 0 packet, or an
                   unknown command type).";
               }
               leaf bad-routes-rcvd {
                 type yang:counter32;
                 description
                   "The number of routes received from this neighbor,
                   in valid RIP packets, which were ignored for any
                   reason (e.g. unknown address family, or invalid
                   metric).";
               }
             } // neighbor
           } // neighbors
           container routes {
             description
               "IPv4 route information.";
             list route {
               key "ipv4-prefix";
               description
                 "A RIPv2 IPv4 route.";

               leaf ipv4-prefix {
                 type inet:ipv4-prefix;
                 description
                   "IP address (in the form A.B.C.D) and prefix length,
                   separated by the slash (/) character. The range of
                   values for the prefix-length is 0 to 32.";
               }
               leaf next-hop {
                 type inet:ipv4-address;
                 description
                   "Next hop IPv4 address.";
               }
               leaf interface {
                 type if:interface-ref;
                 description
                   "The interface that the route uses.";
               }
               uses route-attributes;
             } // route
           } // routes
         } // ipv4
         container ipv6 {
           when "../../rt:type = 'rip:ripng'" {
             description
               "IPv6 address family is supported by RIPng.";
           }
           description
             "IPv6 address family information.";
           container neighbors {
             description
               "IPv6 neighbor information.";
             list neighbor {
               key "ipv6-address";
               description
                 "A RIPv2 RIP neighbor.";

               leaf ipv6-address {
                 type inet:ipv6-address;
                 description
                   "IP address that a RIP neighbor is using as its
                   source address.";
               }
               leaf last-update {
                 type yang:date-and-time;
                 description
                   "The time when the most recent RIP update was
                   received from this neighbor.";
               }
               leaf bad-packets-rcvd {
                 type yang:counter32;
                 description
                   "The number of RIP invalid packets received from
                   this neighbor which were subsequently discarded
                   for any reason (e.g. a version 0 packet, or an
                   unknown command type).";
               }
               leaf bad-routes-rcvd {
                 type yang:counter32;
                 description
                   "The number of routes received from this neighbor,
                   in valid RIP packets, which were ignored for any
                   reason (e.g. unknown address family, or invalid
                   metric).";
               }
             } // neighbor
           } // neighbors
           container routes {
             description
               "IPv6 route information.";
             list route {
               key "ipv6-prefix";
               description
                 "A RIPng IPv6 route.";

               leaf ipv6-prefix {
                 type inet:ipv6-prefix;
                 description
                   "IP address (in the canonical format defined in
                   RFC5952)and prefix length, separated by the slash (/)
                   character. The range of values for the prefix-length
                   is 0 to 128.";
               }
               leaf next-hop {
                 type inet:ipv6-address;
                 description
                   "Next hop IPv6 address.";

               }
               leaf interface {
                 type if:interface-ref;
                 description
                   "The interface that the route uses.";
               }
               uses route-attributes;
             } // route
           } // routes
         } // ipv6

         container statistics {
           if-feature global-statistics;
           description
             "Global statistic counters.";
           leaf discontinuity-time {
             type yang:date-and-time;
             description
               "The time on the most recent occasion at which any one
               or more of the statistic counters suffered a
               discontinuity. If no such discontinuities have occurred
               since the last re-initialization of the local
               management subsystem, then this node contains the time
               the local management subsystem re-initialized itself.";
           }
           leaf requests-rcvd {
             type yang:counter32;
             description
               "The number of requests received by RIP.";
           }
           leaf requests-sent {
             type yang:counter32;
             description
               "The number of requests sent by RIP.";
           }
           leaf responses-rcvd {
             type yang:counter32;
             description
               "The number of responses received by RIP.";
           }
           leaf responses-sent {
             type yang:counter32;
             description
               "The number of responses sent by RIP.";
           }
         }
       } // rip
     } // augment

     /*
      * RPCs
      */

     rpc clear-rip-route {
       description
         "Clears RIP routes from the IP routing table and routes
         redistributed into the RIP protocol for the specified RIP
         instance or for all RIP instances in the current context.";

       input {
         leaf instance-name routing-instance {
           type rt:routing-instance-ref;
           description
             "Routing instance name identifying a specific routing
             instance.
             This leaf is optional for the rpc.
             If it is specified, the rpc will clear routes in the
             specified routing instance;
             if it is not specified, the rpc will clear all routes in
             all routing instances.";
         }
         leaf rip-instance {
           type leafref {
             path "/rt:routing/rt:routing-instance/" "/rt:routing/rt:routing-instance"
               + "[rt:name=current()/../routing-instance]/"
               + "rt:routing-protocols/rt:routing-protocol/rt:name";
           }
           description
             "Instance name identifying the a specific RIP Instance."; instance.
             This leaf is optional for the rpc.
             If it is specified, the rpc will clear all routes in the
             specified RIP instance;
             if it is not specified, the rpc will clear all routes in
             all RIP instances.";
         }
       }
     } // rcp clear-rip-route
   }
   <CODE ENDS>

4. IANA Considerations

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number (and remove this note).

   This document registers the following namespace URIs in the IETF XML
   registry [RFC3688]:

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

5. Security Considerations

   The configuration, state, and action data defined in this document
   are designed to be accessed via the NETCONF protocol [RFC6241]. The
   data-model by itself does not create any security implications. The
   security considerations for the NETCONF protocol are applicable. The
   NETCONF protocol used for sending the data supports authentication
   and encryption.

6. References

6.1. Normative References

   [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the
             Network Configuration Protocol (NETCONF)", RFC 6020,
             October 2010.

   [RFC6991] Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
             July 2013.

   [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman,
             "Network Configuration Protocol (NETCONF)", RFC 6241, June
             2011.

   [RFC2453] G. Malkin, "RIP Version 2", RFC2453, November 1998.

   [RFC2080] G. Malkin and R. Minnear, "RIPng for IPv6", RFC2080,
             January 1997.

   [RFC1724] G. Malkin and F. Baker, "RIP Version 2 MIB Extension",
             RFC1724, November 1994.

6.2. Informative References

   [RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG
             Data Model Documents", RFC 6087, January 2011.

Authors' Addresses

   Xufeng Liu
   Ericsson
   1595 Spring Hill Road, / Kuatro Technologies Inc.
   8281 Greensboro Drive, Suite 500
   Vienna, 200
   McLean, VA 22182 22102
   USA

   Email: xufeng.liu@ericsson.com xliu@kuatrotech.com

   Prateek Sarda
   Ericsson India Global Services Pvt. Ltd.
   Fern Icon, Survey No 28 and 36/5, Doddanakundi Village
   Bangalore, Karnataka 560037
   India

   Email: prateek.sarda@ericsson.com

   Vikram Choudhary
   Huawei Technologies
   Divyashree Techno Park, Whitefield
   Bangalore, Karnataka 560037
   India

   Email: vikram.choudhary@huawei.com