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<rfc category="std"  docName="draft-ietf-rift-yang-11"
     ipr="trust200902">
  <!-- ***** FRONT MATTER ***** -->
  <front>
    <title abbrev="RIFT YANG Model">YANG Data Model for Routing in Fat Trees (RIFT)</title>

	<author fullname="Zheng Zhang" initials="Z" surname="Zhang">
      <organization>ZTE Corporation</organization>  
      <address>
        <postal>
          <street></street>
          
          <city></city>
          
          <region></region>
  
          <code></code>

          <country></country>
        </postal>

        <email>zhang.zheng@zte.com.cn</email>
      </address>
    </author>

	<author fullname="Yuehua Wei" initials="Y" surname="Wei">
      <organization>ZTE Corporation</organization>  
      <address>
        <postal>
          <street></street>
          
          <city></city>
          
          <region></region>
  
          <code></code>

          <country></country>
        </postal>

        <email>wei.yuehua@zte.com.cn</email>
      </address>
    </author>

	<author fullname="Shaowen Ma" initials="S" surname="Ma">
      <organization>Google</organization>  
      <address>
        <postal>
          <street></street>
          
          <city></city>
          
          <region></region>
  
          <code></code>

          <country></country>
        </postal>

        <email>mashaowen@gmail.com</email>
      </address>
    </author>

	<author fullname="Xufeng Liu" initials="X" surname="Liu">
      <organization>Alef Edge</organization>  
      <address>
        <postal>
          <street></street>
          
          <city></city>
          
          <region></region>
  
          <code></code>

          <country></country>
        </postal>

        <email>xufeng.liu.ietf@gmail.com</email>
      </address>
    </author>
    
  <author fullname="Bruno Rijsman" initials="B" surname="Rijsman">
      <organization>Individual</organization>  
      <address>
        <postal>
          <street></street>
          
          <city></city>
          
          <region></region>
  
          <code></code>

          <country></country>
        </postal>

        <email>brunorijsman@gmail.com</email>
      </address>
    </author>   
    
	<date year="2024"/>	
    <area>Routing</area>
    <workgroup>RIFT WG</workgroup>
    <keyword>RIFT, YANG</keyword>
    <abstract>
     <t>
       This document defines a YANG data model for the configuration and
       management of Routing in Fat Trees (RIFT) Protocol. The model is based on YANG 1.1 as defined in 
       RFC7950 and conforms to the Network Management Datastore Architecture
      (NMDA) as described in RFC8342.
     </t>
    </abstract>
  </front>

  <!-- ***** MIDDLE MATTER ***** -->

  <middle>
  <section title="Introduction">
      <t><xref target="I-D.ietf-rift-rift"/> introduces the protocol definition of RIFT. 
          This document defines a YANG data model that can be used to configure
	  and manage the RIFT protocol. This model imports and augments ietf-routing YANG model
	  defined in <xref target="RFC8349"/>.</t> 
      
    <section title="Terminology">
	    <t>The terminology for describing YANG data models is found in 
	      <xref target="RFC6020"/> and <xref target="RFC7950"/>, including:</t>
	    <t>
        <list style="symbols">
          <t>augment</t>
          <t>container</t>
          <t>choice</t>
          <t>data model</t>
          <t>data node</t>
          <t>grouping</t>
          <t>identity</t>
          <t>leaf</t>
          <t>leaf-list</t>
          <t>list</t>
	      <t>module</t>
          <t>uses</t>
	      </list>
	    </t>
          
      <t>The following abbreviations are used in this document and the defined model:</t>
	    <t>RIFT: Routing in Fat Trees <xref target="I-D.ietf-rift-rift"/>.</t>
	  </section>
	
    <section title="Conventions Used in This Document">
	  <t>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 <xref target="RFC2119"/> <xref target="RFC8174"/> 
      when, and only when, they appear in all capitals, as shown here.</t>
	</section>
  
    <section title="Terminology">
	  <t>The content of this section is copied from <xref target="I-D.ietf-rift-rift"/> for reading convenience.</t>
	  <t>LIE: This is an acronym for a "Link Information Element" exchanged on
      all the system's links running RIFT to form _ThreeWay_ adjacencies
      and carry information used to perform Zero Touch Provisioning
      (ZTP) of levels.</t>
	  <t>POD: An acronym for a "Point of Delivery". A self-contained vertical slice or subset of a Clos or Fat Tree
      network containing normally only level 0 and level 1 nodes.  A
      node in a PoD communicates with nodes in other PoDs via the ToF
      nodes. PoDs are numbered to distinguish them and PoD value 0
      (defined later in the encoding schema as _common.default_pod_) is
      used to denote "undefined" or "any" PoD.</t>
	  <t>TIE: This is an acronym for a "Topology Information Element". TIEs are
      exchanged between RIFT nodes to describe parts of a network such
      as links and address prefixes. A TIE has always a direction and a
      type. North TIEs (sometimes abbreviated as N-TIEs) are used when
      dealing with TIEs in the northbound representation and South-TIEs
      (sometimes abbreviated as S-TIEs) for the southbound equivalent.
      TIEs have different types such as node and prefix TIEs.</t>
	</section>
	
	<section title="Tree Diagrams">
      <t>Tree diagrams used in this document follow the notation defined in <xref target="RFC8340"/>.</t>
	  </section>

	  <section title="Prefixes in Data Node Names">
	    <t>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.</t>
   
      <texttable anchor="TABLE_1" title="">

        <ttcol align="left">Prefix</ttcol>
        <ttcol align="left">YANG module</ttcol>
        <ttcol align="left">Reference</ttcol>

        <c>yang</c>
        <c>ietf-yang-types</c>
        <c><xref target="RFC6991"/></c>

        <c>inet</c>
        <c>ietf-inet-types</c>
        <c><xref target="RFC6991"/></c>
  
        <c>rt</c>
        <c>ietf-routing</c>
        <c><xref target="RFC8349"/></c>

        <c>if</c>
        <c>ietf-interfaces</c>
        <c><xref target="RFC8343"/></c>
	
        <c>rt-types</c>
        <c>ietf-routing-types</c>
        <c><xref target="RFC8294"/></c>
        
        <c>iana-rt-types</c>
        <c>iana-routing-types</c>
        <c><xref target="RFC8294"/></c>
        
        <c>key-chain</c>
        <c>ietf-key-chain</c>
        <c><xref target="RFC8177"/></c>
      </texttable>
    </section>
      
	</section>
	 
	<section title="Design of the Data Model"> 
	  <section title="Scope of Model">
	    <t>The model covers RIFT <xref target="I-D.ietf-rift-rift"/>.</t>
      
      <t>This model can be used to configure and manage the 
   RIFT protocol.  The operational state data and statistics
   can be retrieved by this model. The subscription and push
   mechanism defined in <xref target="RFC8639"/> 
   and <xref target="RFC8641"/> can be implemented by
   the user to subscribe to notifications on the data nodes in this
   model.</t>
   
	<t>The model contains all the basic configuration parameters to operate
   the protocol.  Depending on the implementation choices,
   some systems may not allow some of the advanced parameters to be
   configurable.  The occasionally implemented parameters are modeled as
   optional features in this model. 
   This model can be extended, and it has been structured in a way that
   such extensions can be conveniently made.</t>
   
   <t>The RIFT YANG module augments the /routing/control-plane-protocols/
   control-plane-protocol path defined in the ietf-routing module.  The
   ietf-rift model defines a single instance of RIFT.  Multiple instances are
   instantiated as multiple control-plane protocols instances.</t>
    </section>

    <section title="Specification">
	  <t>
	   This model imports and augments ietf-routing YANG model
	   defined in <xref target="RFC8349"/>.
	   Both configuration branch and state branch of <xref target="RFC8349"/> are augmented.
	   The configuration branch covers node base and policy configuration. 

	   The container "rift" is the top level container in this data model.
	   The container is expected to enable RIFT protocol functionality. 
	 </t>
	 
	 <t>The YANG data model defined in this document conforms to the Network
   Management Datastore Architecture (NMDA) <xref target="RFC8342"/>.  
   The operational state data is combined with the associated configuration 
   data in the same hierarchy <xref target="RFC8407"/>.</t>
    
	  </section>
  
    <section title="Overview">
	  <t>The RIFT YANG module defined in this document has all the common
   building blocks for the RIFT protocol.</t>

     <t>The RIFT YANG module augments the /routing/control-plane-protocols/
   control-plane-protocol path defined in the ietf-routing module.  The
   ietf-rift model defines a single instance of RIFT. Multiple instances are
   instantiated as multiple control-plane protocols instances.</t>

    <figure  align="center">
       <artwork align="center"><![CDATA[
module: ietf-rift
  augment /rt:routing/rt:control-plane-protocols
            /rt:control-plane-protocol:
    +--rw rift* [name]
       +--rw name                         string
       +--ro level?                       level
       +--rw system-id                    system-id
       +--rw fabric-id?                   uint16
       +--rw pod?                         uint32
       +--rw configured-level?            level
       +--rw overload
       |  +--rw overload?                   boolean
       |  +--rw (timeout-type)?
       |     +--:(on-startup)
       |     |  +--rw on-startup-timeout?
       |     |          rt-types:timer-value-seconds16
       |     +--:(immediate)
       |        +--rw immediate-timeout?
       |                rt-types:timer-value-seconds16
       +--ro proto-major-ver              uint8
       +--ro proto-minor-ver              uint16
       +--rw hierarchy-indications?       enumeration
       +--rw flood-reduction?             boolean
       +--rw nonce-increasing-interval?   uint16
       +--rw maximum-nonce-delta?         uint8 {nonce-delta-adjust}?
       +--rw adjusted-lifetime?
       |       rt-types:timer-value-seconds16
       +--rw rx-lie-multicast-addr
       |  +--rw ipv4?   inet:ipv4-address
       |  +--rw ipv6?   inet:ipv6-address
       +--rw tx-lie-multicast-addr
       |  +--rw ipv4?   inet:ipv4-address
       |  +--rw ipv6?   inet:ipv6-address
       +--rw lie-tx-port?                 inet:port-number
       +--rw global-link-capabilities
       |  +--rw bfd?                     boolean
       |  +--rw v4-forwarding-capable?   boolean
       |  +--rw mtu-size?                uint32
       +--rw tide-generation-interval?
       |       rt-types:timer-value-seconds16
       +--rw tie-security* [security-type] {tie-security}?
       |  +--rw security-type             enumeration
       |  +--rw (auth-key-chain)?
       |     +--:(auth-key-chain)
       |     |  +--rw key-chain?          key-chain:key-chain-ref
       |     +--:(auth-key-explicit)
       |        +--rw key-id?             uint32
       |        +--rw key?                string
       |        +--rw crypto-algorithm?   identityref
       +--rw algorithm-type?              enumeration
       +--rw instance-label?              uint32 {label-switching}?
       +--ro hal
       |  +--ro hal-value?    level
       |  +--ro system-ids*   system-id
       +--ro miscabled-links*             uint32
       +--rw ttl?                         uint8
       +--rw maximum-clock-delta?         ieee802-1as-timestamp
       +--rw interfaces* [name]
       |  +--ro link-id?                     uint32
       |  +--rw name                         if:interface-ref
       |  +--rw cost?                        uint32
       |  +--rw rx-flood-port?               inet:port-number
       |  +--rw holdtime?
       |  |       rt-types:timer-value-seconds16
       |  +--rw address-families*
       |  |       iana-rt-types:address-family
       |  +--rw advertised-source-addr
       |  |  +--rw ipv4?   inet:ipv4-address-no-zone
       |  |  +--rw ipv6?   inet:ipv6-address-no-zone
       |  +--ro link-direction-type?         enumeration
       |  +--rw broadcast-capable?           boolean
       |  +--rw security {link-security}?
       |  |  +--rw security-type?            enumeration
       |  |  +--rw (auth-key-chain)?
       |  |     +--:(auth-key-chain)
       |  |     |  +--rw key-chain?          key-chain:key-chain-ref
       |  |     +--:(auth-key-explicit)
       |  |        +--rw key-id?             uint32
       |  |        +--rw key?                string
       |  |        +--rw crypto-algorithm?   identityref
       |  +--rw security-checking?           enumeration
       |  +--ro was-the-last-lie-accepted?   boolean
       |  +--ro last-lie-reject-reason?      string
       |  +--ro advertised-in-lies
       |  |  +--ro you-are-flood-repeater?        boolean
       |  |  +--ro not-a-ztp-offer?               boolean
       |  |  +--ro you-are-sending-too-quickly?   boolean
       |  +--rw link-capabilities
       |  |  +--rw bfd?                     boolean
       |  |  +--rw v4-forwarding-capable?   boolean
       |  |  +--rw mtu-size?                uint32
       |  +--ro state                        enumeration
       |  +--ro number-of-flaps?             uint32
       |  +--ro last-state-change?           yang:date-and-time
       |  +--ro last-up?                     yang:date-and-time
       |  +--ro last-down?                   yang:date-and-time
       |  +--ro neighbors* [system-id]
       |     +--ro level?                        level
       |     +--ro system-id                     system-id
       |     +--ro fabric-id?                    uint16
       |     +--ro pod?                          uint32
       |     +--ro proto-major-ver?              uint8
       |     +--ro proto-minor-ver?              uint16
       |     +--ro sent-offer
       |     |  +--ro level?             level
       |     |  +--ro not-a-ztp-offer?   boolean
       |     +--ro received-offer
       |     |  +--ro level?                        level
       |     |  +--ro not-a-ztp-offer?              boolean
       |     |  +--ro best?                         boolean
       |     |  +--ro removed-from-consideration?   boolean
       |     |  +--ro removal-reason?               string
       |     +--ro received-source-addr
       |     |  +--ro ipv4?   inet:ipv4-address-no-zone
       |     |  +--ro ipv6?   inet:ipv6-address-no-zone
       |     +--ro link-id-pair* [remote-id]
       |     |  +--ro local-id?           uint32
       |     |  +--ro remote-id           uint32
       |     |  +--ro if-index?           uint32
       |     |  +--ro if-name?            if:interface-ref
       |     |  +--ro address-families*
       |     |          iana-rt-types:address-family
       |     +--ro cost?                         uint32
       |     +--ro bandwidth?                    uint32
       |     +--ro received-link-capabilities
       |     |  +--ro bfd?                     boolean
       |     |  +--ro v4-forwarding-capable?   boolean
       |     |  +--ro mtu-size?                uint32
       |     +--ro received-in-lies
       |     |  +--ro you-are-flood-repeater?        boolean
       |     |  +--ro not-a-ztp-offer?               boolean
       |     |  +--ro you-are-sending-too-quickly?   boolean
       |     +--ro nbr-flood-port?               inet:port-number
       |     +--ro tx-flood-port?                inet:port-number
       |     +--ro bfd-up?                       boolean
       |     +--ro outer-security-key-id?        uint8
       +--ro database
          +--ro ties*
                  [tie-direction-type originator tie-type tie-number]
             +--ro tie-direction-type      enumeration
             +--ro originator              system-id
             +--ro tie-type                enumeration
             +--ro tie-number              uint32
             +--ro seq?                    uint64
             +--ro origination-time?       ieee802-1as-timestamp
             +--ro origination-lifetime?   uint32
             +--ro remaining-lifetime?     uint32
             +--ro node
             |  +--ro level?                   level
             |  +--ro neighbors* [system-id]
             |  |  +--ro level?                        level
             |  |  +--ro system-id                     system-id
             |  |  +--ro fabric-id?                    uint16
             |  |  +--ro pod?                          uint32
             |  |  +--ro link-id-pair* [remote-id]
             |  |  |  +--ro local-id?           uint32
             |  |  |  +--ro remote-id           uint32
             |  |  |  +--ro if-index?           uint32
             |  |  |  +--ro if-name?            if:interface-ref
             |  |  |  +--ro address-families*
             |  |  |          iana-rt-types:address-family
             |  |  +--ro cost?                         uint32
             |  |  +--ro bandwidth?                    uint32
             |  |  +--ro received-link-capabilities
             |  |     +--ro bfd?                     boolean
             |  |     +--ro v4-forwarding-capable?   boolean
             |  |     +--ro mtu-size?                uint32
             |  +--ro proto-minor-ver?         uint16
             |  +--ro flood-reduction?         boolean
             |  +--ro hierarchy-indications
             |  |  +--ro hierarchy-indications?   enumeration
             |  +--ro overload-flag?           boolean
             |  +--ro name?                    string
             |  +--ro pod?                     uint32
             |  +--ro startup-time?            uint64
             |  +--ro miscabled-links*         uint32
             |  +--ro same-plane-tofs*         system-id
             |  +--ro fabric-id?               uint32
             +--ro prefixes
             |  +--ro prefixes* [prefix]
             |     +--ro prefix               inet:ip-prefix
             |     +--ro tie-type?            enumeration
             |     +--ro metric?              uint32
             |     +--ro tags*                uint64
             |     +--ro monotonic-clock
             |     |  +--ro prefix-sequence-type
             |     |     +--ro timestamp
             |     |     |       ieee802-1as-timestamp
             |     |     +--ro transaction-id?   uint8
             |     +--ro loopback?            boolean
             |     +--ro directly-attached?   boolean
             |     +--ro from-link?           uint32
             |     +--ro label?               uint32
             +--ro key-value
                +--ro key?     binary
                +--ro value?   binary

  notifications:
    +---n error-set
       +--ro tie-level-error
       |  +--ro rift* [name]
       |     +--ro name    string
       |     +--ro ties* [originator]
       |        +--ro tie-direction-type?     enumeration
       |        +--ro originator              system-id
       |        +--ro tie-type?               enumeration
       |        +--ro tie-number?             uint32
       |        +--ro seq?                    uint64
       |        +--ro origination-time?       ieee802-1as-timestamp
       |        +--ro origination-lifetime?   uint32
       |        +--ro remaining-lifetime?     uint32
       +--ro neighbor-error
          +--ro rift* [name]
             +--ro name         string
             +--ro neighbors* [system-id]
                +--ro level?                        level
                +--ro system-id                     system-id
                +--ro fabric-id?                    uint16
                +--ro pod?                          uint32
                +--ro proto-major-ver?              uint8
                +--ro proto-minor-ver?              uint16
                +--ro sent-offer
                |  +--ro level?             level
                |  +--ro not-a-ztp-offer?   boolean
                +--ro received-offer
                |  +--ro level?                        level
                |  +--ro not-a-ztp-offer?              boolean
                |  +--ro best?                         boolean
                |  +--ro removed-from-consideration?   boolean
                |  +--ro removal-reason?               string
                +--ro received-source-addr
                |  +--ro ipv4?   inet:ipv4-address-no-zone
                |  +--ro ipv6?   inet:ipv6-address-no-zone
                +--ro link-id-pair* [remote-id]
                |  +--ro local-id?           uint32
                |  +--ro remote-id           uint32
                |  +--ro if-index?           uint32
                |  +--ro if-name?            if:interface-ref
                |  +--ro address-families*
                |          iana-rt-types:address-family
                +--ro cost?                         uint32
                +--ro bandwidth?                    uint32
                +--ro received-link-capabilities
                |  +--ro bfd?                     boolean
                |  +--ro v4-forwarding-capable?   boolean
                |  +--ro mtu-size?                uint32
                +--ro received-in-lies
                |  +--ro you-are-flood-repeater?        boolean
                |  +--ro not-a-ztp-offer?               boolean
                |  +--ro you-are-sending-too-quickly?   boolean
                +--ro nbr-flood-port?               inet:port-number
                +--ro tx-flood-port?                inet:port-number
                +--ro bfd-up?                       boolean
                +--ro outer-security-key-id?        uint8
            ]]></artwork>
       <postamble></postamble>
      </figure>
    </section>

    <section title="RIFT configuration"> 
    <t>
       The configuration data nodes cover node 
       configuration attributes. 
      RIFT configurations require node base information configurations. 
      Some features can be used to enhance protocol, such as BFD <xref target="RFC5881"/>, flooding-reducing, 
      community attribute.</t>
    </section>

	  <section title="RIFT State"> 
    <t>The state data nodes include node, neighbor, 
       database and kv-store information.</t>
    </section>
	
    <section title="Notifications"> 
    <t>Unexpected TIE and neighbor's layer error should be notified.</t>
    </section>
    
  </section>

	<section title="RIFT YANG model"> 
    <t>This module references <xref target="I-D.ietf-rift-rift"/>, 
    <xref target="RFC5881"/>, <xref target="RFC6991"/>, 
	  <xref target="RFC8177"/>, <xref target="RFC8294"/>, <xref target="RFC8343"/>, 
    <xref target="RFC8349"/>, <xref target="RFC8505"/>, 
    <xref target="IEEE8021AS"/>.</t>
  
     <figure  align="center">
            <artwork align="center"><![CDATA[
<CODE BEGINS> file "ietf-rift@2024-06-06.yang"
module ietf-rift {

  yang-version 1.1;

  namespace "urn:ietf:params:xml:ns:yang:ietf-rift";
  prefix rift;

  import ietf-inet-types {
    prefix "inet";
    reference 
      "RFC 6991: Common YANG Data Types";
  }

  import ietf-yang-types {
    prefix "yang";
    reference 
      "RFC 6991: Common YANG Data Types";
  }

  import ietf-routing {
    prefix "rt";
    reference
      "RFC 8349: A YANG Data Model for Routing Management
       (NMDA Version)";
  }

  import ietf-interfaces {
    prefix "if";
    reference
      "RFC 8343: A YANG Data Model for Interface Management";
  }

  import ietf-routing-types {
    prefix "rt-types";
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area";
  }

  import iana-routing-types {
    prefix "iana-rt-types";
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area";
  }
  
  import ietf-key-chain {
    prefix "key-chain";
    reference 
      "RFC 8177: YANG Data Model for Key Chains";
  }

  organization
    "IETF RIFT (Routing In Fat Trees) Working Group";

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

     Editor:   Zheng Zhang
               <mailto:zhang.zheng@zte.com.cn>

     Editor:   Yuehua Wei
               <mailto:wei.yuehua@zte.com.cn>

     Editor:   Shaowen Ma
               <mailto:mashaowen@gmail.com>

     Editor:   Xufeng Liu
               <mailto:xufeng.liu.ietf@gmail.com>
               
     Editor:   Bruno Rijsman
               <mailto:brunorijsman@gmail.com>";

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

  description
    "This YANG module defines the generic configuration and
     operational state for the RIFT protocol common to all
     vendor implementations.  It is intended that the module
     will be extended by vendors to define vendor-specific
     RIFT configuration parameters and policies --
     for example, route maps or route policies.

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

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

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

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject 
     to the license terms contained in, the Revised BSD License 
     set forth in Section 4.c of the IETF Trust's Legal 
     Provisions Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

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

  revision 2024-06-06 {
    description 
      "Initial revision.";
    reference 
      "RFCXXXX: YANG Data Model for Routing in Fat Trees 
      (RIFT).";
  }

  /*
   * Features
   */

  feature nonce-delta-adjust {
    description
      "Support weak nonce delta adjusting which is used in 
       security in section 6.9.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
  }

  feature label-switching {
    description
      "Support label switching for instance distinguishing in
       section 6.8.8.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
  }
  
  feature tie-security {
    description
      "Support security function described in section 6.9.3 
       for the TIE exchange.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
  }
  
  feature link-security {
    description
      "Support security function of link described in 
       section 6.9.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
  }

  typedef system-id {
    type string {
      pattern
'[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}';
    }
    description
      "This type defines RIFT system id using pattern,
       the system id looks like: 0021.2FFF.FEB5.6E10";
  }

  typedef level {
    type uint8 {
      range "0 .. 24";
    }
    default "0";
    description 
      "The value of node level.";
  }

  typedef ieee802-1as-timestamp {
    type uint64;
    units "seconds";
    description
      "Timestamp per IEEE802.1AS. It is advertised with prefix 
       to achieve mobility as described in section 6.8.4.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees. 
       IEEE8021AS: Timing and Synchronization for Time-Sensitive 
                   Applications in Bridged Local Area Networks";
  }

  /*
   * Identity
   */
  identity rift {
    base rt:routing-protocol;
    description 
      "Identity for the RIFT routing protocol.";
    reference 
      "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
  }

  /*
   * Groupings
   */

  grouping address-families {
    leaf-list address-families {
      type iana-rt-types:address-family;
      description 
        "Indication which address families are up on the
         interface.";
    }
    description
      "Containing address families on the interface.";
  }
  
  grouping hierarchy-indications {
    leaf hierarchy-indications {
      type enumeration {
        enum "leaf-only" {
          description
            "The node will never leave the 
             'bottom of the hierarchy'.";
        }
        enum "leaf-only-and-leaf-2-leaf-procedures" {
          description 
            "This means leaf to leaf.";
        }
        enum "top-of-fabric" {
          description 
            "The node is 'top of fabric'.";
        }
      }
      description 
        "The hierarchy indications of this node.";
    }
    description 
      "Flags indicating node configuration in case of ZTP";
  }
  
  grouping node-capability {
    leaf proto-minor-ver {
      type uint16;
      description
        "Represents the minor protocol encoding schema
         version of this node.";
    }
    leaf flood-reduction {
      type boolean;
      description
        "If the value is set to 'true', it means that 
         this node enables the flood reduction function.";
    }
    container hierarchy-indications {
      config false;
      description 
        "The hierarchy-indications of the node.";
      uses hierarchy-indications;
    }
    description
      "The supported capabilities of this node.";
  }
  
  grouping tie-type {
    leaf tie-type {
      type enumeration {
        enum "illegal" {
          description 
            "The illegal TIE.";
        }
        enum "min-tie-type" {
          description 
            "The minimum TIE.";
        }
        enum "node" {
          description 
            "The node TIE.";
        }
        enum "prefix" {
          description 
            "The prefix TIE.";
        }
        enum "positive-disaggregation-prefix" {
          description 
            "The positive disaggregation prefix TIE.";
        }
        enum "negative-disaggregation-prefix" {
          description 
            "The negative disaggregation prefix TIE.";
        }
        enum "pgp-prefix" {
          description 
            "The policy guide prefix TIE.";
        }
        enum "key-value" {
          description 
            "The key value TIE.";
        }
        enum "external-prefix" {
          description 
            "The external prefix TIE.";
        }
        enum "positive-external-disaggregation-prefix" {
          description
            "The positive external disaggregation prefix TIE.";
        }
        enum "max-tie-type" {
          description 
            "The maximum TIE.";
        }
      }
      description 
        "The types of TIE.";
    }
    description 
      "The types of TIE";
  }
  
  grouping prefix-attribute {
    
    leaf metric {
      type uint32;
      description 
        "The metric of this prefix.";
    }
    leaf-list tags {
      type uint64;
      description 
        "The tags of this prefix.";
    }
    container monotonic-clock {
      container prefix-sequence-type {
        leaf timestamp {
          type ieee802-1as-timestamp;
          mandatory true;
          description
            "The timestamp per 802.1AS can be advertised
             with the desired prefix North TIEs.";
        }
        leaf transaction-id {
          type uint8;
          description
            "As per RFC 8505, a sequence number called a
             Transaction ID (TID) with a prefix can be
             advertised.";
          reference 
            "RFC 8505: Registration Extensions for IPv6 over 
             Low-Power Wireless Personal Area Network (6LoWPAN) 
             Neighbor Discovery";
        }
        description
          "As described in section 6.8.4, the prefix
           sequence attribute which can be advertised
           for mobility.";
        reference 
          "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
      }
      description
        "The monotonic clock for mobile addresses.";
    }
    leaf loopback {
      type boolean;
      description
        "If the value is set to 'true', it 
         indicates if the interface is a node loopback.
         According to section 6.8.10, the node's loopback
         address can be injected into North and South
         Prefix TIEs for node reachability.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    leaf directly-attached {
      type boolean;
      description
        "If the value is set to 'true', it indicates that the 
         prefix is directly attached, i.e. should be routed to 
         even if the node is in overload.";
    }
    leaf from-link {
      type uint32;
      description
        "In case of locally originated prefixes,
         i.e. interface addresses this can describe which
         link the address belongs to.";
    }
    leaf label {
      type uint32;
      description
        "Per prefix significant label.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    description
      "The attributes of the prefix.";
  }
  
  grouping security {
    leaf security-type {
      type enumeration {
        enum public {
          description 
            "Public key type described in section 6.9.";
        }
        enum private {
          description 
            "Private key type described in section 6.9.";
        }
        enum shared {
          description 
            "Shared key type described in section 6.9.";
        }
      }
      description 
        "The security type.";
    }

    choice auth-key-chain {
      description
        "Key chain or explicit key parameter specification";
      case auth-key-chain {
        leaf key-chain {
          type key-chain:key-chain-ref;
          description
            "key-chain name.";
        }
      }
      case auth-key-explicit {
        leaf key-id {
          type uint32;
          description 
            "Key Identifier";
        }
        leaf key {
          type string;
          description
            "Authentication key. The length of the key may be 
             dependent on the cryptographic algorithm.";
        }
        leaf crypto-algorithm {
          type identityref {
            base key-chain:crypto-algorithm;
          }
          description
            "Cryptographic algorithm associated with key.";
        }
      }
    }
    description 
      "The security parameters.";
  }
   
  grouping base-node-info {
    leaf level {
      type level;
      config false;
      description 
        "The level of this node.";
    }
    leaf system-id {
      type system-id;
      mandatory true;
      description
        "Each node is identified via a system-id which is 64 
         bits wide.";
    }
    leaf fabric-id {
      type uint16;
      description
        "The optional id of the fabric.";
    }
    leaf pod {
      type uint32 {
        range "1..max";
      }
      description
        "The identifier of the Point of Delivery (PoD). 
         A PoD is the self-contained vertical slice of a
         Clos or Fat Tree network containing normally only 
         level 0 and level 1 nodes. It communicates with nodes 
         in other PoDs via the spine. Making this leaf 
         unspecified indicates that the PoD is 'undefined'.";
    }
    description 
      "The base information of a node.";
  } // base-node-info

  grouping link-capabilities {
    leaf bfd {
      type boolean;
      default "true";
      description
        "If this value is set to 'true', it means that
         BFD function is enabled on the neighbor.";
      reference 
        "RFC 5881: Bidirectional Forwarding Detection (BFD) 
         for IPv4 and IPv6 (Single Hop)";
    }
    leaf v4-forwarding-capable {
      type boolean;
      default "true";
      description
        "If this value is set to 'true', it means that
         the neighbor supports v4 forwarding.";
    }
    leaf mtu-size {
      type uint32;
      default "1400";
      description
        "MTU of the link.";
    }
    description 
      "The features of neighbor.";
  } // link-capabilities

  grouping addresses {
    leaf ipv4 {
      type inet:ipv4-address-no-zone;
      description 
        "IPv4 address to be used.";
    }
    leaf ipv6 {
      type inet:ipv6-address-no-zone;
      description 
        "IPv6 address to be used.";
    }
    description 
      "IPv4 and/or IPv6 address to be used.";
  }

  grouping lie-elements {
    leaf you-are-flood-repeater {
      type boolean;
      description
        "If the neighbor on this link is flooding repeater
         described in section 6.3.9. When this value is 
         set to 'true', the value can be carried in exchanged
         packet.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    leaf not-a-ztp-offer {
      type boolean;
      description
        "As described in section 6.7. When this value is
         set to 'true', the flag can be carried in the LIE
         packet. When the value received in the LIE from
         neighbor, it indicates the level on the LIE MUST
         NOT be used to derive a ZTP level by the receiving
         node.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    leaf you-are-sending-too-quickly {
      type boolean;
      description
        "Can be optionally set to indicate to neighbor that
         packet losses are seen on reception based on packet
         numbers or the rate is too high. The receiver SHOULD
         temporarily slow down flooding rates. When this value
         is set to 'true', the flag can be carried in packet.";
    }
    description 
      "The elements set in the LIEs.";
  } // lie-elements

  grouping link-id-pair {
    leaf local-id {
      type uint32;
      description 
        "The local-id of link connect to this neighbor.";
    }
    leaf remote-id {
      type uint32;
      description 
        "The remote-id to reach this neighbor.";
    }
    leaf if-index {
      type uint32;
      description 
        "The local index of this interface.";
    }
    leaf if-name {
      type if:interface-ref;
      description 
        "The name of this interface.";
    }
    uses address-families;
    description
      "A pair of local and remote link-id to identify a link 
       between two nodes.";
  } // link-id-pair

  grouping neighbor-node {
    list link-id-pair {
      key "remote-id";
      uses link-id-pair;
      description
        "The Multiple parallel links to this neighbor.";
    }
    leaf cost {
      type uint32;
      description 
        "The cost value advertised by the neighbor.";
    }
    leaf bandwidth {
      type uint32;
      description
        "Total bits bandwith to neighbor, this will be
         normally sum of the bandwidths of all the
         parallel links.";
    }
    container received-link-capabilities {
      uses link-capabilities;
      description
        "The link capabilities advertised by the neighbor.";
    }
    description 
      "The neighbor information indicated in node TIE.";
  } // neighbor-node

  grouping neighbor {
    leaf proto-major-ver {
      type uint8;
      description
        "Represents protocol encoding schema major version of 
         this neighbor.";
    }
    leaf proto-minor-ver {
      type uint16;
      description
        "Represents protocol encoding schema minor version of 
         this neighbor.";
    }
    container sent-offer {
      leaf level {
        type level;
        description 
          "The level value.";
      }
      leaf not-a-ztp-offer {
        type boolean;
        description 
          "If the value is set to 'true', it indicates the 
           level on the LIE MUST NOT be used to derive a 
           ZTP level by the neighbor.";
      }
      description
        "The level sent to the neighbor in case the neighbor
         needs to be offered.";
    }
    container received-offer {
      leaf level {
        type level;
        description 
          "The level value.";
      }
      leaf not-a-ztp-offer {
        type boolean;
        description
          "If the value is set to 'true', it indicates the 
           level on the received LIE MUST NOT be used to 
           derive a ZTP level.";
      }
      leaf best {
        type boolean;
        description
          "If the value is set to 'true', it means that 
           the level is the best level received from all
           the neighbors.";
      }
      leaf removed-from-consideration {
        type boolean;
        description
          "If the value is set to 'true', it means that 
           the level value is not considered to be used.";
      }
      leaf removal-reason {
        type string;
        description
          "The reason why this value is not considered to
           be used.";
      }
      description
        "The level offered to the interface from the neighbor.
         And if the level value is considered to be used.";
    }
    container received-source-addr {
      uses addresses;
      description
        "The source address of LIE and TIE packets from
         the neighbor.";
    } // received-offer
    uses neighbor-node;
    container received-in-lies {
      uses lie-elements;
      description 
        "The attributes received from this neighbor.";
    }
    leaf nbr-flood-port {
      type inet:port-number;
      default "915";
      description
        "The UDP port which is used by the neighbor to flood 
         TIEs.";
    }
    leaf tx-flood-port {
      type inet:port-number;
      default "915";
      description
        "The UDP port which is used by the node to flood 
         TIEs to the neighbor.";
    }
    leaf bfd-up {
      type boolean;
      description
        "If the value is set to 'true', it means that the link 
         is protected by established BFD session.";
    }
    leaf outer-security-key-id {
      type uint8;
      description
        "As described in section 6.9.3, the received security
         key id from the neighbor.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    description 
      "The neighbor information.";
  } // neighbor

  grouping link-direction-type {
    leaf link-direction-type {
      type enumeration {
        enum illegal {
          description 
            "Illegal direction.";
        }
        enum south {
          description 
            "A link to a node one level down.";
        }
        enum north {
          description 
            "A link to a node one level up.";
        }
        enum east-west {
          description 
            "A link to a node in the same level.";
        }
        enum max {
          description 
            "The max value of direction.";
        }
      }
      config false;
      description 
        "The type of a link.";
    }
    description 
      "The type of a link.";
  } // link-direction-type
  
  grouping tie-direction-type {
    leaf tie-direction-type {
      type enumeration {
        enum illegal {
          description 
            "Illegal direction.";
        }
        enum south {
          description 
            "The direction to a node one level down.";
        }
        enum north {
          description 
            "The direction to a node one level up.";
        }
        enum max {
          description 
            "The max value of direction.";
        }
      }
      config false;
      description 
        "The direction type of a TIE.";
    }
    description 
      "The direction type of a TIE.";
  } // tie-direction-type

  grouping tie-header {
    uses tie-direction-type;
    leaf originator {
      type system-id;
      description 
        "The originator's system-id of this TIE.";
    }
    
    uses tie-type;

    leaf tie-number {
      type uint32;
      description 
        "The number of this TIE";
    }

    leaf seq {
      type uint64;
      description
        "As described in section 6.3.1, the sequence number
         of a TIE.";
      reference 
        "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
    }
    leaf origination-time {
      type ieee802-1as-timestamp;
      description
        "Absolute timestamp when the TIE was generated. 
         This can be used on fabrics with synchronized 
         clock to prevent lifetime modification attacks.";
    }
    leaf origination-lifetime {
      type uint32;
      description
        "Original lifetime when the TIE was generated.
         This can be used on fabrics with synchronized clock 
         to prevent lifetime modification attacks.";
    }
    leaf remaining-lifetime {
      type uint32;
      description
        "The remaining lifetime of the TIE.";
    }

    description
      "TIE is the acronym for 'Topology Information Element'.
       TIEs are exchanged between RIFT nodes to describe parts
       of a network such as links and address prefixes.
       This is the TIE header information.";
  } // tie-header

  /*
   * Data nodes
   */
  augment "/rt:routing/rt:control-plane-protocols"
           + "/rt:control-plane-protocol" {
    when "derived-from-or-self(rt:type, 'rift:rift')" {
      description
        "This augment is only valid when routing protocol
         instance type is 'RIFT'.";
    }
    description 
      "RIFT ( Routing in Fat Trees ) YANG model.";

    list rift {
      key "name";
      leaf name {
        type string;
        description 
          "The RIFT instance's name.";
      }
      
      uses base-node-info;
      leaf configured-level {
        type level;
        description
          "The configured level value of this node. 
           If the 'hierarchy-indications' is set to 'leaf-only' 
           or 'leaf-only-and-leaf-2-leaf-procedures', this 
           value means the leaf level. 
           And the combination of this value and 
           'hierarchy-indications' can also be used to indicate 
           the maximum level value of 'top-of-fabric-level'.";
      }
      container overload {
        description 
          "If the overload in TIEs can be set 
           and the timeout value with according type.";
        leaf overload {
          type boolean;
          description 
            "If the value is set to 'true', it means that 
             the overload bit in TIEs can be set.";
        }
        choice timeout-type {
          description 
            "The value of timeout timer for overloading. 
             This makes sense when overload is set to 'TRUE'.";
          case on-startup {
            leaf on-startup-timeout {
              type rt-types:timer-value-seconds16;
              description 
                "Node goes into overload until this timer 
                 expires when starting up.";
            }
          }
          case immediate {
            leaf immediate-timeout {
              type rt-types:timer-value-seconds16;
              description 
                "Set overload and remove after the timeout 
                 expired.";
            }
          }
        }
      }

      leaf proto-major-ver {
        type uint8;
        config false;
        mandatory true;
        description
          "Represents protocol encoding schema major version.";
      }
      leaf proto-minor-ver {
        type uint16;
        config false;
        mandatory true;
        description
          "Represents protocol encoding schema minor version.";
      }
      uses hierarchy-indications;
      leaf flood-reduction {
        type boolean;
        description
          "If the node supports flood reduction function defined 
           in section 6.3.8. If this value is set to 'true', 
           it means that the flood reduction function is 
           enabled.";
        reference 
          "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
      }
      leaf nonce-increasing-interval {
        type uint16;
        units seconds;
        description
          "The configurable nonce increasing interval.";
      }
      leaf maximum-nonce-delta {
        if-feature nonce-delta-adjust;
        type uint8 {
          range "1..5";
        }
        description
          "The configurable valid nonce delta value used for
           security. It is used as vulnerability window defined
           in section 6.9.4.
           If the nonces in received packet exceeds the range
           indicated by this value, the packet MUST be 
           discarded.";
        reference 
          "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
      }
      leaf adjusted-lifetime {
        type rt-types:timer-value-seconds16;
        units seconds;
        description
          "The adjusted lifetime may affect the TIE stability.
           Be careful to change this parameter.
           This should be prohibited less than 2*purge-lifetime.";
      }
      container rx-lie-multicast-addr {
        leaf ipv4 {
          type inet:ipv4-address;
          default "224.0.0.121";
          description 
            "The configurable LIE receiving IPv4 multicast
             address. 
             Different multicast addresses can be used for 
             receiving and sending.";
        }
        leaf ipv6 {
          type inet:ipv6-address;
          default "FF02::A1F7";
          description 
            "The configurable LIE receiving IPv6 multicast
             address. 
             Different multicast addresses can be used for 
             receiving and sending.";
        }
        description 
          "The configurable LIE receiving IPv4/IPv6 multicast
           address. 
           Different multicast addresses can be used for 
           receiving and sending.";
      }
      container tx-lie-multicast-addr {
        leaf ipv4 {
          type inet:ipv4-address;
          description 
            "The configurable LIE sending IPv4 multicast 
             address. 
             Different multicast addresses can be used for 
             receiving and sending.";
        }
        leaf ipv6 {
          type inet:ipv6-address;
          description 
            "The configurable LIE sending IPv6 multicast 
             address. 
             Different multicast addresses can be used for 
             receiving and sending.";
        }
        description 
          "The configurable LIE sending IPv4/IPv6 multicast 
           address. 
           Different multicast addresses can be used for 
           receiving and sending.";
      }
      leaf lie-tx-port {
        type inet:port-number;
        default "914";
        description
          "The UDP port of LIE packet sending. The default port
           number is 914. The value can be set to other value
           associated with different RIFT instance.";
      }

      container global-link-capabilities {
        uses link-capabilities;
        description
          "The node default link capabilities. It can be 
           overwrite by the configuration underneath interface 
           and neighbor.";
      }

      leaf tide-generation-interval {
        type rt-types:timer-value-seconds16;
        units seconds;
        default "5";
        description 
          "The TIDE generation interval.";
      }

      list tie-security {
        if-feature tie-security;
        key "security-type";
        uses security;
        description 
          "As described in section 6.9.3, the security function 
           used for the TIE exchange.";
        reference 
          "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
      }
      leaf algorithm-type {
        type enumeration {
          enum spf {
            description 
              "The algorithm is SPF.";
          }
          enum all-path {
            description 
              "The algorithm is all-path.";
          }
        }
        description 
          "The possible algorithm types.";
      }
      leaf instance-label {
        if-feature label-switching;
        type uint32;
        description
          "As per section 6.8.8, a locally significant, 
           downstream assigned, interface specific label may 
           be advertised in its LIEs. This value can be used 
           to distinguish among multiple RIFT instances.";
        reference 
          "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
      }

      container hal {
        config false;
        leaf hal-value {
          type level;
          description
            "The highest defined level value seen from all 
             valid level offers received.";
        }
        leaf-list system-ids{
          type system-id;
          description
            "The node's system-id of the offered level comes 
             from.";
        }
        description 
          "The highest defined level and the offered nodes set.";
      }
      
      leaf-list miscabled-links {
        type uint32;
        config false;
        description 
          "List of miscabled links.";
      }
      
      leaf ttl {
        type uint8 {
          range "1 | 255";
        }
        default "1";
        description 
          "The IPv4 TTL or IPv6 HL used for LIE and TIE 
           sending/receiving.";     
      }
      
      leaf maximum-clock-delta {
        type ieee802-1as-timestamp;
        description
          "As described in section 6.8.4, the maximum drift for 
           the timestamp comparing.";
      }
      
      list interfaces {
        key "name";
        leaf link-id {
          type uint32;
          config false;
          description 
            "The local id of this interface.";
        }
        leaf name {
          type if:interface-ref;
          description 
            "The interface's name.";
        }
        leaf cost {
          type uint32;
          description
            "The cost from this interface to the neighbor.";
        }
        leaf rx-flood-port {
          type inet:port-number;
          default "915";
          description
            "The UDP port which is used to receive flooded
             TIEs. The default port number is 915. The value can
             be set to other value associated with different
             RIFT instance.";
        }
        leaf holdtime {
          type rt-types:timer-value-seconds16;
          units seconds;
          default "3";
          description 
            "The holding time of LIE.";
        }
        
        uses address-families;
        container advertised-source-addr {
          uses addresses;
          description
            "The address used in the advertised LIE and TIE
             packets.";
        }
        
        uses link-direction-type;
        
        leaf broadcast-capable {
          type boolean;
          description
            "If LIE can be received by broadcast address 
             as decribed in section 6.2.";
        }
        
        container security {
          if-feature link-security;
          uses security;
          description 
            "As described in section 6.9.3, the security 
             function used for this interface.";
          reference 
            "I-D.ietf-rift-rift: RIFT: Routing in Fat Trees";
        }
        
        leaf security-checking {
          type enumeration {
            enum "no-checking" {
              description 
                "The security envelop does not be checked.";
            }
            enum "permissive" {
              description 
                "The security envelop checking is permissive.";
            }
            enum "loose" {
              description 
                "The security envelop checking is loose.";
            }
            enum "strict" {
              description 
                "The security envelop checking is strict.";
            }
          }
          description 
            "The possible security checking types. 
             Only one type can be set at the same time.";
        }

        leaf was-the-last-lie-accepted {
          type boolean;
          config false;
          description
            "If the value is set to 'true', it means that 
             the most recently received LIE was accepted. 
             If the LIE was rejected, the neighbor error
             notifications should be used to find the reason.";
        }
        leaf last-lie-reject-reason {
          type string;
          config false;
          description
            "Description for the reject reason of the last LIE.";
        }
        container advertised-in-lies {
          config false;
          uses lie-elements;
          description
            "The attributes advertised in the LIEs from
             this interface.";
        }
        container link-capabilities {
          uses link-capabilities;
          description
            "The interface's link capabilities.";
        }
        leaf state {
          type enumeration {
            enum "OneWay" {
              description 
                "The initial state of neighbor.";
            }
            enum "TwoWay" {
              description 
                "This means leaf to leaf.";
            }
            enum "ThreeWay" {
              description 
                "The node is 'top of fabric'.";
            }
            enum "Multiple-Neighbors-Wait" {
              description 
                "The node is 'top of fabric'.";
            }
          }
          config false;
          mandatory true;
          description 
            "The hierarchy indications of this node.";
        }
        leaf number-of-flaps {
          type uint32;
          config false;
          description
            "The number of interface state flaps.";
        }
        leaf last-state-change {
          type yang:date-and-time;
          config false;
          description 
            "Time duration in the current state.";
        }
        leaf last-up {
          type yang:date-and-time;
          config false;
          description 
            "The last time of up.";
        }
        leaf last-down {
          type yang:date-and-time;
          config false;
          description 
            "The last time of down.";
        }
        
        list neighbors {
          key "system-id";
          config false;
          uses base-node-info;
          uses neighbor;
          description 
            "The neighbor's information.";
        }

        description 
          "The interface information on this node.";
      } // list interface

      container database {
        config false;
        list ties {
          key "tie-direction-type originator tie-type tie-number";
          description
            "A list of TIEs (Topology Information Elements).";
          uses tie-header;

          container node {
            leaf level {
              type level;
              config false;
              description 
                "The level of this node.";
            }
            list neighbors {
              key "system-id";
              uses base-node-info;
              uses neighbor-node;
              description 
                "The node TIE information of a neighbor.";
            }
            uses node-capability;
            leaf overload-flag {
              type boolean;
              description 
                "If the value is set to 'true', it means that 
                 the overload bit in TIEs is set.";
            }
            leaf name {
              type string;
              description
                "The name of this node. It won't be used as the 
                 key of node, just used for description.";
            }
            leaf pod {
              type uint32;
              description
                "Point of Delivery. The self-contained vertical 
                 slice of a Clos or Fat Tree network containing 
                 normally only level 0 and level 1 nodes. It 
                 communicates with nodes in other PoDs via the 
                 spine. We number PoDs to distinguish them and 
                 use PoD #0 to denote 'undefined' PoD.";
            }
            leaf startup-time {
              type uint64;
              description 
                "Startup time of the node.";
            }
            leaf-list miscabled-links {
              type uint32;
              config false;
                description 
                  "List of miscabled links.";
            }
            leaf-list same-plane-tofs {
              type system-id;
              config false;
                description 
                  "ToFs in the same plane. Only carried by ToF. 
                   Multiple Node TIEs can carry disjoint sets of 
                   ToFs which MUST be joined to form a single 
                   set.";
            }
            leaf fabric-id {
              type uint32;
              config false;
                description 
                  "The optional ID of the Fabric configured.";
            }
            description 
              "The node element information in this TIE.";
          } // node

          container prefixes {
            description 
              "The prefix element information in this TIE.";
            list prefixes {
              key "prefix";
              leaf prefix {
                type inet:ip-prefix;
                description 
                  "The prefix information.";
              }
              uses tie-type;
              uses prefix-attribute;
              description 
                "The prefix set information.";
            }
          }

          container key-value {
            leaf key {
              type binary;
              description 
                "The type of key value combination.";
            }
            leaf value {
              type binary;
              description 
                "The value of key value combination.";
            }
            description
              "The information used to distinguish a Key/Value
               pair. When the type of kv is set to 'node',
               node-element is making sense. When the type of
               kv is set to other values except 'node',
               prefix-info is making sense.";
          } // kv-store
        } // ties
        description 
          "The TIEs information in database.";
      }// container database
      description 
        "RIFT configuration and state data.";
	}//rift
  }//augment

  /*
   * Notifications
   */
  notification error-set {
    description 
      "The errors notification of RIFT.";
    container tie-level-error {
	  description 
        "The TIE errors notification of RIFT.";
		
      list rift {
        key "name";
        leaf name {
          type string;
          description 
            "The RIFT instance's name.";
        }
        list ties {
          key "originator";
          uses tie-header;
          description 
            "The level is undefined in the LIEs.";
        }
        description 
          "The TIE errors set.";
      }
    }
    container neighbor-error {
      description 
        "The neighbor errors notification of RIFT.";
	  list rift {
        key "name";
        leaf name {
          type string;
          description 
            "The RIFT instance's name.";
        }
        list neighbors {
          key "system-id";
          uses base-node-info;
          uses neighbor;
          description 
            "The information of a neighbor.";
        }
        description 
          "The neighbor errors set.";
      }
    }
  }
}
<CODE ENDS>
            ]]></artwork>
       <postamble></postamble>
      </figure>
    </section>

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

   <t>The Network Configuration Access Control Model (NACM) <xref target="RFC8341"/> provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.</t>

   <t>There are a number of data nodes defined in this YANG module 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.  Writable data node represent
   configuration of each instance, node, interface, etc.  
   These correspond to the following schema node:</t>
   
    <t>
      <list style="symbols">
        <t>/rift</t>
	    </list>
	  </t>
    
    <t>Modifying the configuration may cause all the RIFT neighborship to be rebuilt.
      For example, the configuration changing of configured-level or system-id, will lead to all the neighbor connections of this node rebuilt.
      The incorrect modification of authentication, except for the neighbor connection broken, will
      lead to the permanent connection broken. The modification of interface, will lead to the neighbor state changing.
      In general, unauthorized modification of most RIFT configurations will pose there own
      set of security risks and the "Security Considerations" in the
      respective reference RFCs should be consulted.</t>
      
    <t>Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:</t>
   
    <t>
      <list style="symbols">
        <t>/rift</t>
		<t>/rift/tie-security</t>
        <t>/rift/interface</t>
        <t>/rift/neighbor</t>
        <t>/rift/database</t>
	    </list>
	  </t>
    
    <t>The exposure of the database will expose the detailed topology 
	of the network. Network operators may consider their topologies 
	to be sensitive confidential data.</t>

   <t>For RIFT authentication, configuration is supported via the
   specification of key-chains <xref target="RFC8177"/> or the direct 
   specification of key and authentication algorithm.  
   Hence, authentication configuration inherits the security 
   considerations of <xref target="RFC8177"/>.  This includes the 
   considerations with respect to the
   local storage and handling of authentication keys.</t>
   
   <t>The actual authentication key data (whether locally specified 
   or part of a key chain) is sensitive and needs to be kept secret 
   from unauthorized parties; compromise of the key data would allow 
   an attacker to forge RIFT packet that would be accepted as 
   authentic, potentially compromising the entire domain.</t>

	</section>

   <section title="IANA Considerations"> 
	<t>RFC Ed.: Please replace all occurrences of 'XXXX' with the
   actual RFC number (and remove this note).</t>

   <t>This document registers a URI in the IETF XML registry 
   <xref target="RFC3688"/>.
   Following the format in <xref target="RFC3688"/>, the following 
   registration is requested to be made:</t>

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

   <t>This document also requests one new YANG module name in the YANG
   Module Names registry <xref target="RFC6020"/> with the following 
   suggestion:</t>

       <t>name: ietf-rift</t>
       <t>namespace: urn:ietf:params:xml:ns:yang:ietf-rift</t>
       <t>prefix: rift</t>
       <t>reference: RFC XXXX</t>
   </section>
	
	<section title="Acknowledgement"> 
	<t>The authors would like to thank Tony Przygienda, 
	Benchong Xu (xu.benchong@zte.com.cn), Tom Petch for their review, 
	valuable comments and suggestions.</t>
	</section>
	
  </middle>

  <!--  *****BACK MATTER ***** -->

  <back>
  
    <references title='Normative References'>
    &rfc2119;
    &rfc5881;
    &rfc6020;
    &rfc6241;
    &rfc6242;
    &rfc6991;
    &rfc7950;
    &rfc8040;
    &rfc8174;
    &rfc8177;
    &rfc8294;
    &rfc8340;
    &rfc8341;
    &rfc8342;
    &rfc8343;
    &rfc8349;
    &rfc8446;
    &rfc8505;
    <reference anchor="IEEE8021AS" target="https://ieeexplore.ieee.org/document/5741898/">
      <front>
        <title>IEEE Standard for Local and Metropolitan Area
          Networks - Timing and Synchronization for Time-Sensitive
          Applications in Bridged Local Area Networks</title>
        <author/>
        <date/>
      </front>
    </reference>
    &I-D.ietf-rift-rift;
    </references>
    
    <references title='Informative References'>
  	&rfc3688;
    &rfc8407;
    &rfc8639;
    &rfc8641;
    </references>
    
	</back>
</rfc>
