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) 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 9314; see the
RFC itself for full legal notices.";

    reference
      "RFC 5880: Bidirectional Forwarding Detection (BFD)
       RFC 9314: YANG Data Model for Bidirectional Forwarding
      Detection (BFD)";


    revision "2022-09-22" {
      description
        "This revision is not backwards compatible with the
previous version of this model.

This revision adds an 'if-feature' statement called
'client-base-cfg-parms' for client configuration parameters.
Clients expecting to use those parameters now need to
verify that the server declares support of the feature
before depending on the presence of the parameters.

The change was introduced for clients that do not need
them and have to deviate to prevent them from being
included.";
      reference
        "RFC 9314: 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";

    }

    feature client-base-cfg-parms {
      description
        "This feature allows protocol models to configure BFD client
session parameters.";
      reference
        "RFC 9314: YANG Data Model for Bidirectional Forwarding
        	  Detection (BFD).";

    }

    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