module ietf-bfd-types {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-bfd-types";

    prefix bfd-types;

    import iana-bfd-types {
      prefix iana-bfd-types;
      reference
        "RFC 9127: YANG Data Model for Bidirectional Forwarding
        Detection (BFD)";


    }
    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-key-chain {
      prefix key-chain;
      reference
        "RFC 8177: YANG Data Model for Key Chains";


    }

    organization "IETF BFD Working Group";

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

     Editor:   Reshad Rahman
               <mailto:reshad@yahoo.com>

     Editor:   Lianshu Zheng
               <mailto:veronique_cheng@hotmail.com>

     Editor:   Mahesh Jethanandani
               <mailto:mjethanandani@gmail.com>";

    description
      "This module contains a collection of BFD-specific YANG data type
     definitions, as per RFC 5880, and also groupings that are common
     to other BFD YANG modules.

     Copyright (c) 2021 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

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

     This version of this YANG module is part of RFC 9127; see the
     RFC itself for full legal notices.";

    reference
      "RFC 5880: Bidirectional Forwarding Detection (BFD)
       RFC 9127: YANG Data Model for Bidirectional Forwarding
      Detection (BFD)";


    revision "2021-10-21" {
      description "Initial revision.";
      reference
        "RFC 9127: YANG Data Model for Bidirectional Forwarding
        Detection (BFD)";

    }


    feature single-minimum-interval {
      description
        "This feature indicates that the server supports configuration
       of one minimum interval value that is used for both transmit
       and receive minimum intervals.";
    }

    feature authentication {
      description
        "This feature indicates that the server supports BFD
       authentication.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD),
        Section 6.7";

    }

    feature demand-mode {
      description
        "This feature indicates that the server supports BFD Demand
       mode.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD),
        Section 6.6";

    }

    feature echo-mode {
      description
        "This feature indicates that the server supports BFD Echo
       mode.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD),
        Section 6.4";

    }

    identity bfdv1 {
      base rt:control-plane-protocol;
      description "BFD protocol version 1.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD)";

    }

    identity path-type {
      description
        "Base identity for the BFD path type.  The path type indicates
       the type of path on which BFD is running.";
    }

    identity path-ip-sh {
      base path-type;
      description "BFD on IP single-hop.";
      reference
        "RFC 5881: Bidirectional Forwarding Detection (BFD)
        for IPv4 and IPv6 (Single Hop)";

    }

    identity path-ip-mh {
      base path-type;
      description
        "BFD on IP multihop paths.";
      reference
        "RFC 5883: Bidirectional Forwarding Detection (BFD) for
        Multihop Paths";

    }

    identity path-mpls-te {
      base path-type;
      description
        "BFD on MPLS Traffic Engineering.";
      reference
        "RFC 5884: Bidirectional Forwarding Detection (BFD)
        for MPLS Label Switched Paths (LSPs)";

    }

    identity path-mpls-lsp {
      base path-type;
      description
        "BFD on an MPLS Label Switched Path.";
      reference
        "RFC 5884: Bidirectional Forwarding Detection (BFD)
        for MPLS Label Switched Paths (LSPs)";

    }

    identity path-lag {
      base path-type;
      description
        "Micro-BFD on LAG member links.";
      reference
        "RFC 7130: Bidirectional Forwarding Detection (BFD) on
        Link Aggregation Group (LAG) Interfaces";

    }

    identity encap-type {
      description
        "Base identity for BFD encapsulation type.";
    }

    identity encap-ip {
      base encap-type;
      description
        "BFD with IP encapsulation.";
    }

    typedef discriminator {
      type uint32;
      description
        "BFD Discriminator as described in RFC 5880.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD)";

    }

    typedef state {
      type enumeration {
        enum "adminDown" {
          value 0;
          description "'adminDown' state.";
        }
        enum "down" {
          value 1;
          description "'Down' state.";
        }
        enum "init" {
          value 2;
          description "'Init' state.";
        }
        enum "up" {
          value 3;
          description "'Up' state.";
        }
      }
      description
        "BFD states as defined in RFC 5880.";
    }

    typedef multiplier {
      type uint8 {
        range "1..255";
      }
      description
        "BFD multiplier as described in RFC 5880.";
    }

    typedef hops {
      type uint8 {
        range "1..255";
      }
      description
        "This corresponds to Time To Live for IPv4 and corresponds to
       the hop limit for IPv6.";
    }
  }  // module ietf-bfd-types