BESS Working Group                                          P. Brissette
                                                               A.Sajassi
Internet Draft                                              Cisco System
Intended Status: Proposed Standard                               H. Shah
Expires: January 9, September 14, 2017                            Ciena Corporation
                                                                   Z. Li
                                                     Huawei Technologies
                                                                 I. Chen
                                                                Ericsson
                                                                   Jabil
                                                         K. Tiruveedhula
                                                        Juniper Networks
                                                              I. Hussain
                                                    Infinera Corporation
                                                              J. Rabadan
                                                                   Nokia

                                                            July 8, 2016

                                                          March 13, 2017

                        Yang Data Model for EVPN
                      draft-ietf-bess-evpn-yang-01
                      draft-ietf-bess-evpn-yang-02

Abstract

   This document describes a YANG data model for Ethernet VPN services.
   The model is agnostic of the underlay. It apply to MPLS as well as to
   VxLAN encapsulation. The model is also agnostic of the services
   including E-LAN, E-LINE and E-TREE services. Any "add-on" features
   such as EVPN IRB, EVPN overlay, etc. are for future investigation.
   This document mainly focuses on EVPN and Ethernet-Segment instance
   framework.

Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as
   Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."
   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html

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Copyright and License Notice

   Copyright (c) 2016 2017 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Convention

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2. Specification of Requirements . . . . . . . . . . . . . . . . .  5
   3. EVPN YANG Model . . . . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  Overview . . . . . . . . . . . . . . . . . . . . . . . . .  5
     3.2 Ethernet-Segment Model . . . . . . . . . . . . . . . . . . .  6
     3.3 EVPN Model . . . . . . . . . . . . . . . . . . . . . . . . .  6
   4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . .  7
     4.1 Ethernet Segment Yang Module . . . . . . . . . . . . . . . .  7
     4.2 EVPN Yang Module . . . . . . . . . . . . . . . . . . . . . .  9
   5. Security Considerations . . . . . . . . . . . . . . . . . . . . 11
   6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 11
   7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 11
   8. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     8.1. Normative References  . . . . . . . . . . . . . . . . . . . 12
     8.2. Informative References  . . . . . . . . . . . . . . . . . . 12
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12

1.  Introduction

   The Network Configuration Protocol (NETCONF) [RFC6241] is a network
   management protocol that defines mechanisms to manage network
   devices. YANG [RFC6020] is a modular language that represents data
   structures in an XML or JSON tree format, and is used as a data
   modeling language for the NETCONF.

   This document introduces a YANG data model for Ethernet VPN services
   (EVPN) [RFC7432], Provider Backbone Bridging Combined with Ethernet
   VPN (PBB-EVPN) [RFC7623] as well as other WG draft such as EVPN-VPWS,
   etc...
   etc.  The EVPN services runs over MPLS and VxLAN underlay.

   The Yang data model in this document defines Ethernet VPN based
   services.  The model will leverage the definitions used in other IETF
   Yang draft such as L2VPN Yang.

   The goal is to propose a data object model consisting of building
   blocks that can be assembled in different order to realize different
   EVPN-based services. The definition work is undertaken initially by a
   smaller working group with members representing various vendors and
   service providers.  The EVPN basic framework consist of two modules:
   EVPN and Ethernet-Segment. These models are completely orthogonal.
   They usually work in pair but user can definitely use one or the
   other for its own need.

   The data model is defined for following constructs that are used for
   managing the services:

      o  Configuration

      o  Operational State

      o  Executables (Actions)

      o  Notifications

   The document is organized to first define the data model for the
   configuration, operational state, actions and notifications of EVPN
   and Ethernet-Segment.

   The EVPN data object model defined in this document uses the instance
   centric approach whereby EVPN service attributes are specified for a
   given EVPN instance.

   The Ethernet-Segment data object model defined in this document refer
   to a specific interface. That interface can be a physical interface,
   a bundle interface or virtual interface. The latter includes
   pseudowires. The purpose of creating a separate module is due to the
   fact that it can be used without having the need to have EVPN
   configured as layer 2 service. For example, an access node can be
   dual-homed to two service nodes servicing a VPLS core. The access
   connectivity can be represented by an Ethernet-Segment where EVPN BGP
   DF election is performed over both service nodes. The core remains
   VPLS where no EVPN instance is required.
2. Specification of Requirements

      The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
   NOT",   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
   in this document are to be interpreted as described in [RFC2119].

3. EVPN YANG Model

3.1.  Overview

      Two top level module, Ethernet-Segment and EVPN, are defined. The
   Ethernet-Segment contains a list of interface to which any Ethernet-
   Segment attributes are configured/applied.

      The EVPN module has 2 main containers: common and instance. The
   first one has common attributes to all VPNs where as the latter has
   attributes specific to an EVI. This document state the scope of the
   EVPN object models definition. The following documents are within the
   scope. This is not an exhaustive list but a representation of
   documents that are covered for this work:

      o   Requirements for EVPN: RFC 7209
      o   EVPN: RFC 7432
      o   PBB-EVPN: RFC 7623

   The integration with L2VPN instance Yang model is being done as part
   of the L2VPN Yang model.
   Following documents will be covered at that time:
      o   VPWS support in EVPN:
      draft-ietf-bess-evpn-vpws
      o   E-TREE Support in EVPN & PBB-EVPN:
      draft-ietf-bess-evpn-etree
      o   (PBB-)EVPN Seamless Integration with (PBB-)VPLS:
      draft-ietf-bess-evpn-vpls-seamless-integ
      o   EVPN Virtual Ethernet Segment:
      draft-sajassi-bess-evpn-virtual-eth-segment

   The VxLAN aspect and the work related to Layer 3 is also for future
   definition. Following documents will be covered at that time:

      o   IP Prefix Advertisement in EVPN:
      draft-ietf-bess-evpn-prefix-advertisement
      o   VXLAN DCI Using EVPN:
      draft-boutros-l2vpn-vxlan-evpn
      o   A Network Virtualization Overlay Solution using EVPN:
      draft-ietf-bess-evpn-overlay-
      o   Interconnect Solution for EVPN Overlay networks:
      draft-ietf-bess-dci-evpn-overlay
      o   Integrated Routing and Bridging in EVPN:
      draft-ietf-bess-evpn-inter-subnet-forwarding

3.2 Ethernet-Segment Model

   The Ethernet-Segment data model has a list of ES where each refer to
   an interface. All attributes are optional due to auto-sensing default
   mode where all values are auto-derive from the network connectivity.

   module: ietf-ethernet-segment
       +--rw ethernet-segments
       |  +--rw ethernet-segment* [name]
       |     +--rw name                           string
       |     +--rw (ac-or-pw)?
       |     |  +--:(ac)
       |     |  |  +--rw ac?                            string
       |     |  +--:(pw)
       |     |     +--rw pw?                            string
       |     +--rw ethernet-segment-identifier?   uint32
       |     +--rw (active-mode)
       |     |  +--:(single-active)
       |     |  |  +--rw single-active-mode?            empty
       |     |  +--:(all-active)
       |     |     +--rw all-active-mode?               empty
       |     +--rw pbb-parameters {ethernet-segment-pbb-params}?
       |     |  +--rw backbone-src-mac?   yang:mac-address
       |     +--rw bgp-parameters
       |     |  +--rw common
       |     |     +--rw rd-rt* [route-distinguisher]
       |     |                  {ethernet-segment-bgp-params}?
       |     |        +--rw route-distinguisher    string
       |     |              rt-types:route-distinguisher
       |     |        +--rw vpn-target* [rt-value] [route-target]
       |     |           +--rw rt-value    string route-target
       |     |                 rt-types:route-target
       |     |           +--rw rt-type     bgp-rt-type route-target-type
       |     |                 rt-types:route-target-type
       |     +--rw df-election
       |     |  +--rw (df-election-method)?
       |     |  |  +--:(highest-random-weight)
       |     |  |     +--rw hrw?                  boolean
       |     |  +--rw election-wait-time?   uint32
       |     +--rw ead-evi-route?                 boolean
       +--ro ethernet-segments-state
          +--ro ethernet-segment-state* [name]
             +--ro name                           string
             +--ro service-type?                  string
             +--ro status?                        status-type
             +--ro (ac-or-pw)?
             |  +--:(ac)
             |  |  +--ro ac?                            string
             |  +--:(pw)
             |     +--ro pw?                            string
             +--ro interface-status?              status-type
             +--ro ethernet-segment-identifier?   uint32
             +--ro active-mode?                   string
             +--ro pbb-parameters {ethernet-segment-pbb-params}?
             |  +--ro backbone-src-mac?   yang:mac-address
             +--ro bgp-parameters
             |  +--ro common
             |     +--ro rd-rt* [route-distinguisher]
             |                  {ethernet-segment-bgp-params}?
             |        +--ro route-distinguisher    string
             |              rt-types:route-distinguisher
             |        +--ro vpn-target* [rt-value] [route-target]
             |           +--ro rt-value    string route-target
             |                 rt-types:route-target
             |           +--ro rt-type     bgp-rt-type route-target-type
             |                 rt-types:route-target-type
             +--ro df-election
             |  +--ro hrw-enabled?          boolean
             |  +--ro election-wait-time?   uint32
             +--ro ead-evi-route-enabled?         boolean
             +--ro esi-label?                     string
             +--ro member*
             |  +--ro ip-address?   inet:ip-address
             +--ro df*
                +--ro service-identifier?   uint32
                +--ro vlan?                 uint32
                +--ro ip-address?           inet:ip-address

3.3 EVPN Model

      The evpn-instances container contains a list of evpn-instance.
   Each entry of the evpn-instance represents a different Ethernet VPN
   and it is represented by a EVI. Again, mainly all attributes are
   optional for the same reason as for the Ethernet-Segment module.

   module: ietf-evpn
       +--rw evpn
       |  +--rw common
       |  |  +--rw (replication-type)?
       |  |     +--:(ingress-replication)
       |  |     |  +--rw ingress-replication?   boolean
       |  |     +--:(p2mp-replication)
       |  |        +--rw p2mp-replication?      boolean
       |  +--rw evpn-instances
       |     +--rw evpn-instance* [name]
       |        +--rw name                                string
       |        +--rw evi?                                uint32
       |        +--rw pbb-parameters {evpn-pbb-params}?
       |        |  +--rw source-bmac?   yang:hex-string
       |        +--rw bgp-parameters
       |        |  +--rw common
       |        |     +--rw rd-rt* [route-distinguisher]
       |        |                  {evpn-bgp-params}?
       |        |        +--rw route-distinguisher    string
       |        |              rt-types:route-distinguisher
       |        |        +--rw vpn-target* [rt-value] [route-target]
       |        |           +--rw rt-value    string route-target
       |        |                 rt-types:route-target
       |        |           +--rw rt-type     bgp-rt-type route-target-type
       |        |                 rt-types:route-target-type
       |        +--rw arp-proxy?                          boolean
       |        +--rw arp-suppression?                    boolean
       |        +--rw nd-proxy?                           boolean
       |        +--rw nd-suppression?                     boolean
       |        +--rw underlay-multicast?                 boolean
       |        +--rw flood-unknown-unicast-supression?   boolean
       +--rw evpn-state
          +--ro evpn-instances-state
             +--ro evpn-instance-state* evpn-instance*
                +--ro name? string
                +--ro evi? uint32
                +--ro pbb-parameters {evpn-pbb-params}?
                |  +--ro source-bmac?   yang:hex-string
                +--ro bgp-parameters
                |  +--ro common
                |     +--ro rd-rt* [route-distinguisher]
                |                  {evpn-bgp-params}?
                |        +--ro route-distinguisher    string
                |                 rt-types:route-distinguisher
                |        +--ro vpn-target* [rt-value] [route-target]
                |           +--ro rt-value    string route-target rt-types:route-target
                |           +--ro rt-type     bgp-rt-type route-target-type
                |                 rt-types:route-target-type
                +--ro advertise-mac-suppression-enabled?         boolean
                +--ro arp-proxy-enabled?                         boolean
                +--ro arp-suppression-enabled?                   boolean
                +--ro nd-proxy-enabled?                          boolean
                +--ro nd-suppression-enabled?                    boolean
                +--ro underlay-multicast-enabled?                boolean
                +--ro flood-unknown-unicast-suppression-enabled? boolean
                +--ro routes
                |  +--ro ethernet-auto-discovery-route*
                |  |  +--ro rd-rt* [route-distinguisher]
                |  |  |  +--ro route-distinguisher    string
                |  |  |        rt-types:route-distinguisher
                |  |  |  +--ro vpn-target* [rt-value] [route-target]
                |  |  |     +--ro rt-value    string route-target    rt-types:route-target
                |  |  +--ro ethernet-segment-identifier?   uint32
                |  |  +--ro ethernet-tag?                  uint32
                |  |  +--ro path*
                |  |     +--ro next-hop?   inet:ip-address
                |  |     +--ro label?      mpls:mpls-label      rt-types:mpls-label
                |  |     +--ro detail
                |  |        +--ro attributes
                |  |        |  +--ro extended-community*   string
                |  |        +--ro bestpath?     empty
                |  +--ro mac-ip-advertisement-route*
                |  |  +--ro rd-rt* [route-distinguisher]
                |  |  |  +--ro route-distinguisher    string
                |  |  |        rt-types:route-distinguisher
                |  |  |  +--ro vpn-target* [rt-value] [route-target]
                |  |  |     +--ro rt-value    string route-target    rt-types:route-target
                |  |  +--ro ethernet-segment-identifier?   uint32
                |  |  +--ro ethernet-tag?                  uint32
                |  |  +--ro mac-address? yang:hex-string
                |  |  +--ro mac-address-length?            uint8
                |  |  +--ro ip-prefix?   inet:ip-prefix
                |  |  +--ro path*
                |  |     +--ro next-hop?   inet:ip-address
                |  |     +--ro label?      mpls:mpls-label      rt-types:mpls-label
                |  |     +--ro label2?     mpls:mpls-label     rt-types:mpls-label
                |  |     +--ro detail
                |  |        +--ro attributes
                |  |        |  +--ro extended-community*   string
                |  |        +--ro bestpath?     empty
                |  +--ro inclusive-multicast-ethernet-tag-route*
                |  |  +--ro rd-rt* [route-distinguisher]
                |  |  |  +--ro route-distinguisher    string
                |  |  |        rt-types:route-distinguisher
                |  |  |  +--ro vpn-target* [rt-value] [route-target]
                |  |  |     +--ro rt-value    string route-target    rt-types:route-target
                |  |  +--ro ethernet-segment-identifier?   uint32
                |  |  +--ro originator-ip-prefix? inet:ip-prefix
                |  |  +--ro path*
                |  |     +--ro next-hop?   inet:ip-address
                |  |     +--ro label?      mpls:mpls-label      rt-types:mpls-label
                |  |     +--ro detail
                |  |        +--ro attributes
                |  |        |  +--ro extended-community*   string
                |  |        +--ro bestpath?     empty
                |  +--ro ethernet-segment-route*
                |  |  +--ro rd-rt* [route-distinguisher]
                |  |  |  +--ro route-distinguisher    string
                |  |  |        rt-types:route-distinguisher
                |  |  |  +--ro vpn-target* [rt-value] [route-target]
                |  |  |     +--ro rt-value    string route-target    rt-types:route-target
                |  |  +--ro ethernet-segment-identifier?   uint32
                |  |  +--ro originator-ip-prefix?     inet:ip-prefix
                |  |  +--ro path*
                |  |     +--ro next-hop?   inet:ip-address
                |  |     +--ro detail
                |  |        +--ro attributes
                |  |        |  +--ro extended-community*   string
                |  |        +--ro bestpath?     empty
                |  +--ro ip-prefix-route*
                |     +--ro rd-rt* [route-distinguisher]
                |     |  +--ro route-distinguisher    string
                |     |        rt-types:route-distinguisher
                |     |  +--ro vpn-target* [rt-value] [route-target]
                |     |     +--ro rt-value    string route-target    rt-types:route-target
                |     +--ro ethernet-segment-identifier?   uint32
                |     +--ro ip-prefix?  inet:ip-prefix
                |     +--ro path*
                |        +--ro next-hop?   inet:ip-address
                |        +--ro label?      mpls:mpls-label      rt-types:mpls-label
                |        +--ro detail
                |           +--ro attributes
                |           |  +--ro extended-community*   string
                |           +--ro bestpath?     empty
                +--ro statistics
                   +--ro tx-count?   uint32
                   +--ro rx-count?   uint32
                   +--ro detail
                      +--ro broadcast-tx-count?   uint32
                      +--ro broadcast-rx-count?   uint32
                      +--ro multicast-tx-count?   uint32
                      +--ro multicast-rx-count?   uint32
                      +--ro unicast-tx-count?     uint32
                      +--ro unicast-rx-count?     uint32

     augment /l2vpn:l2vpn/l2vpn:l2vpn-instances/l2vpn:l2vpn-instance:
       +--rw evpn-instance?   evpn-instance-ref
     augment /l2vpn:l2vpn-state/
             l2vpn:l2vpn-instances-state/l2vpn:l2vpn-instance:
       +--ro evpn-instance?   string

4. YANG Module

      The EVPN configuration container is logically divided into
   following high level config areas:

4.1 Ethernet Segment Yang Module

   <CODE BEGINS> file "ietf-ethernet-segment@2016-07-08.yang" "ietf-ethernet-segment@2017-03-13.yang"
   module ietf-ethernet-segment {
     namespace "urn:ietf:params:xml:ns:yang:ietf-ethernet-segment";
     prefix "es";

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

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

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

     organization  "ietf";
     contact       "ietf";
     description   "ethernet segment";

     revision "2017-03-13" {
       description " - Updated to use BGP parameters from " +
                   "   ietf-routing-types.yang instead of from " +
                   "   ietf-evpn.yang " +
                   "";
       reference   "";
     }

     revision "2016-07-08" {
       description "   - Added the configuration option to enable or " +
                   "     disable per-EVI/EAD route " +
                   "   - Added PBB parameter backbone-src-mac " +
                   "   - Added operational state branch, initially " +
                   "     to match the configuration branch" +
                   "";
       reference   "";
     }

     revision "2016-06-23" {
       description "WG document adoption";
       reference   "";
     }

     revision "2015-10-15" {
       description "Initial revision";
       reference   "";
     }

     /* Features */

     feature ethernet-segment-bgp-params {
       description "Ethernet segment's BGP parameters";
     }

     feature ethernet-segment-pbb-params {
       description "Ethernet segment's PBB parameters";
     }

     /* Typedefs */

     typedef status-type {
       type enumeration {
         enum up {
           description "Status is up";
         }
         enum down {
           description "Status is down";
         }
       }
       description "status type";
     }

     /* EVPN Ethernet Segment YANG Model */

     container ethernet-segments {

       description "ethernet-segment";
       list ethernet-segment {
         key "name";
         leaf name {
           type string;
           description "Name of the ethernet segment";

         }
         choice ac-or-pw {
           description "ac-or-pw";
           case ac {
             leaf ac {
               type string;
               description "Eventual reference to standard " +
                           "attachment circuit definition";
             }
           }
           case pw {
             leaf pw {
               type string;
               description "Eventual reference to standard " +
                           "pseudowire definition";
             }
           }
         }
         leaf ethernet-segment-identifier {
           type uint32;
           description "Ethernet segment identifier (esi)";
         }
         choice active-mode {
           mandatory true;
           description "Choice of active mode";
           case single-active {
             leaf single-active-mode {
               type empty;
               description "single-active-mode";
             }
           }
           case all-active {
             leaf all-active-mode {
               type empty;
               description "all-active-mode";
             }
           }
         }
         container pbb-parameters {
           if-feature ethernet-segment-pbb-params;
           description "PBB configuration";
           leaf backbone-src-mac {
             type yang:mac-address;
             description "backbone-src-mac, only if this is a PBB";
           }
         }
         uses evpn:bgp-parameters-grp
         container bgp-parameters {
           description "BGP parameters";
           container common {
             description "BGP parameters common to all pseudowires";
             list rd-rt {
               if-feature ethernet-segment-bgp-params;
               key "route-distinguisher";
               leaf route-distinguisher {
                 type rt-types:route-distinguisher;
                 description "Route distinguisher";
               }
               uses rt-types:vpn-route-targets;
               description "A list of route distinguishers and " +
                           "corresponding VPN route targets";
             }
           }
         }
         container df-election {
           description "df-election";
           choice df-election-method {
             description "Choice of df election method";
             case highest-random-weight {
               leaf hrw {
                 type boolean;
                 description "Enable (TRUE) or disable (FALSE) " +
                             "highest random weight";
               }
             }
           }
           leaf election-wait-time {
             type uint32;
             description "election-wait-time";
           }
         }
         leaf ead-evi-route {
           type boolean;
           default false;
           description "Enable (true) or disable (false) ead-evi-route";
         }
         description "An ethernet segment";
       }
     }

     container ethernet-segments-state {
       config false;
       description "Ethernet segmet operational state";
       list ethernet-segment-state {
         key "name";
         leaf name {
           type string;
           description "Name of the ethernet segment";
         }
         leaf service-type {
           type string;
           description "service-type";
         }
         leaf status {
           type status-type;
           description "Ethernet segment status";
         }
         choice ac-or-pw {
           description "ac-or-pw";
           case ac {
             leaf ac {
               type string;
               description "Name of attachment circuit";
             }
           }
           case pw {
             leaf pw {
               type string;
               description "Name of pseudowire";
             }
           }
         }
         leaf interface-status {
           type status-type;
           description "interface status";
         }
         leaf ethernet-segment-identifier {
           type uint32;
           description "Ethernet segment identifier (esi)";
         }
         leaf active-mode {
           type string;
           description "Single-active-mode/all-active-mode";
         }
         container pbb-parameters {
           if-feature "ethernet-segment-pbb-params";
           description "PBB configuration";
           leaf backbone-src-mac {
             type yang:mac-address;
             description "backbone-src-mac, only if this is a PBB";
           }
         }
         uses evpn:bgp-parameters-grp
         container bgp-parameters {
           description "BGP parameters";
           container common {
             description "BGP parameters common to all pseudowires";
             list rd-rt {
               if-feature ethernet-segment-bgp-params;
               key "route-distinguisher";
               leaf route-distinguisher {
                 type rt-types:route-distinguisher;
                 description "Route distinguisher";
               }
               uses rt-types:vpn-route-targets;
               description "A list of route distinghishers and " +
                           "corresponding route targets";
             }
           }
         }
         container df-election {
           description "df-election";
           leaf hrw-enabled {
             type boolean;
             description "hrw-enabled is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf election-wait-time {
             type uint32;
             description "election-wait-time";
           }
         }
         leaf ead-evi-route-enabled {
           type boolean;
           description "ead-evi-route is enabled (TRUE) " +
                       "or disabled (FALSE)";
         }
         leaf esi-label {
           type string;
           description "esi-label";
         }
         list member {
           leaf ip-address {
             type inet:ip-address;
             description "ip-address";
           }
           description "member of the ethernet segment";
         }
         list df {
           leaf service-identifier {
             type uint32;
             description "service-identifier";
           }
           leaf vlan {
             type uint32;
             description "vlan";
           }
           leaf ip-address {
             type inet:ip-address;
             description "ip-address";
           }
           description "df of an evpn instance's vlan";
         }
         description "An ethernet segment";
       }
     }
   }

   <CODE ENDS>

4.2 EVPN Yang Module

   <CODE BEGINS> file "ietf-evpn@2016-07-08.yang" "ietf-evpn@2017-03-13.yang"
   module ietf-evpn {
     namespace "urn:ietf:params:xml:ns:yang:ietf-evpn";
     prefix "evpn";

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

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

     import ietf-yang-types ietf-l2vpn {
       prefix "yang"; "l2vpn";
     }

     import ietf-routing-types {
       prefix "rt-types";
     }

     organization  "ietf";
     contact       "ietf";
     description   "evpn";

     revision "2017-03-13" {
       description " - Added an augment to base L2VPN model to " +
                   "   reference an EVPN instance " +
                   " - Reused ietf-routing-types.yang " +
                   "   vpn-route-targets grouping instead of " +
                   "   defining it in this module " +
                   "";
       reference   "";
     }

     revision "2016-07-08" {
       description " - Added operational state" +
                   " - Added a configuration knob to enable/disable " +
                   "   underlay-multicast " +
                   " - Added a configuration knob to enable/disable " +
                   "   flooding of unknonw unicast " +
                   " - Added several configuration knobs " +
                   "   to manage ARP and ND" +
                   "";
       reference   "";
     }

     revision "2016-06-23" {
       description "WG document adoption";
       reference   "";
     }

     revision "2015-10-15" {
       description "Initial revision";
       reference   "";
     }

     feature evpn-bgp-params {
       description "EVPN's BGP parameters";
     }

     feature evpn-pbb-params {
       description "EVPN's PBB parameters";
     }

     /* Typedefs */

     typedef bgp-rt-type evpn-instance-ref {
       type enumeration {
         enum import leafref {
           description "For import";
         path "/evpn/evpn-instances/evpn-instance/name";
       }
         enum export {
       description "For export";
         }
         enum both {
           description "For both import and export";
         }
       }
       description "BGP route-target type. Import from BGP YANG"; "A leafref type to an EVPN instance";
     }

     /* Groupings */

     grouping bgp-rd-grp {
       description "BGP RD grouping";
       leaf route-distinguisher route-rd-rt-grp {
         type string;
       description "BGP RD";
       }
     } "A grouping bgp-rd-rt-grp {
       description "BGP RD-RT grouping"; for a route's route distinguishers " +
                   "and route targets";
       list rd-rt {
         key "route-distinguisher";
         leaf route-distinguisher {
           type string; rt-types:route-distinguisher;
           description "BGP RD"; "Route distinguisher";
         }
         list vpn-target {
           key "rt-value"; "route-target";
           leaf rt-value route-target {
             type string; rt-types:route-target;
             description "BGP route target";
           }
           description "List "A list of route targets";
         }
         description "List of RD";
       }
     }

     grouping bgp-parameters-grp {
       description "BGP parameters grouping";
       container bgp-parameters {
         description "BGP parameters";
         container common {
           description "Common BGP parameters";
           uses bgp-rd-rt-grp {
             refine "rd-rt" {
               max-elements 1;
             }
             augment "rd-rt/vpn-target" {
               description "Add type of RT";
               leaf rt-type {
                 type bgp-rt-type;
                 mandatory true;
                 description "Type "A list of RT";
               }
             }
           }
         }
       }
     }

     grouping common-route-parameters-grp {
       description "common-route-parameters-grp";
       uses bgp-rd-rt-grp;
       leaf ethernet-segment-identifier {
         type uint32;
         description "Ethernet segment identifier (esi)"; route distinguishers and " +
                     "corresponding VPN route targets";
       }
     }

     grouping next-hop-label-grp {
       description "next-hop-label-grp";
       leaf next-hop {
         type inet:ip-address;
         description "next-hop";
       }
       leaf label {
         type mpls:mpls-label; rt-types:mpls-label;
         description "label";
       }
     }

     grouping next-hop-label2-grp {
       description "next-hop-label2-grp";
       leaf label2 {
         type mpls:mpls-label; rt-types:mpls-label;
         description "label2";
       }
     }

     grouping path-detail-grp {
       description "path-detail-grp";
       container detail {
         config false;
         description "path details";
         container attributes {
           leaf-list extended-community {
             type string;
             description "extended-community";
           }
           description "attributes";
         }
         leaf bestpath {
           type empty;
           description "Indicate this path is the best path";
         }
       }
     }

     /* EVPN YANG Model */

     container evpn {
       description "evpn";
       container common {
         description "common epn attributes";
         choice replication-type {
           description "A choice of replication type";
           case ingress-replication {
             leaf ingress-replication {
               type boolean;
               description "ingress-replication";
             }
           }
           case p2mp-replication {
             leaf p2mp-replication {
               type boolean;
               description "p2mp-replication";
             }
           }
         }
       }
       container evpn-instances {
         description "evpn-instances";
         list evpn-instance {
           key "name";
           description "An EVPN instance";
           leaf name {
             type string;
             description "Name of EVPN instance";
           }
           leaf evi {
             type uint32;
             description "evi";
           }
           container pbb-parameters {
             if-feature "evpn-pbb-params";
             description "PBB parameters";
             leaf source-bmac {
               type yang:hex-string;
               description "source-bmac";
             }
           }
           uses bgp-parameters-grp
           container bgp-parameters {
             description "BGP parameters";
             container common {
               description "BGP parameters common to all pseudowires";
               list rd-rt {
                 if-feature "evpn-bgp-params"; evpn-bgp-params;
                 key "route-distinguisher";
                 leaf route-distinguisher {
                   type rt-types:route-distinguisher;
                   description "Route distinguisher";
                 }
                 uses rt-types:vpn-route-targets;
                 description "A list of route distinguishers and " +
                             "corresponding VPN route targets";
               }
             }
           }
           leaf arp-proxy {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) ARP proxy";
           }
           leaf arp-suppression {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) " +
                         "ARP suppression";
           }
           leaf nd-proxy {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) ND proxy";
           }
           leaf nd-suppression {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) " +
                         "ND suppression";
           }
           leaf underlay-multicast {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) " +
                         "underlay multicast";
           }
           leaf flood-unknown-unicast-supression {
             type boolean;
             default false;
             description "Enable (TRUE) or disable (FALSE) " +
                         "flood unknown unicast suppression";
           }
         }
       }
     }

     container evpn-state {
       description "EVPN operational state";
       container evpn-instances-state {
         config false;
         description "evpn-instances-state";
         list evpn-instance-state evpn-instance {
           description "The state of an EVPN instance";
           leaf name {
             type string;
             description "Name of EVPN instance";
           }
           leaf evi {
             type uint32;
             description "evi";
           }
           container pbb-parameters {
             if-feature "evpn-pbb-params";
             description "PBB parameters";
             leaf source-bmac {
               type yang:hex-string;
               description "source-bmac";
             }
           }
           uses bgp-parameters-grp
           container bgp-parameters {
             description "BGP parameters";
             container common {
               description "BGP parameters common to all pseudowires";
               list rd-rt {
                 if-feature "evpn-bgp-params"; evpn-bgp-params;
                 key "route-distinguisher";
                 leaf route-distinguisher {
                   type rt-types:route-distinguisher;
                   description "Route distinguisher";
                 }
                 uses rt-types:vpn-route-targets;
                 description "A list of route distinguishers and " +
                             "corresponding VPN route targets";
               }
             }
           }
           leaf advertise-mac-suppression-enabled {
             type boolean;
             description "advertise-mac-suppression " +
                         "is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf arp-proxy-enabled {
             type boolean;
             description "arp-proxy is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf arp-suppression-enabled {
             type boolean;
             description "arp-suppression is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf nd-proxy-enabled {
             type boolean;
             description "nd-proxy is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf nd-suppression-enabled {
             type boolean;
             description "nd-suppression is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf underlay-multicast-enabled {
             type boolean;
             description "underlay-multicast is enabled (TRUE) " +
                         "or disabled (FALSE)";
           }
           leaf flood-unknown-unicast-suppression-enabled {
             type boolean;
             description "flood-unknown-unicast-suppression is " +
                         "enabled (TRUE) or disabled (FALSE)";
           }
           container routes {
             description "routes";
             list ethernet-auto-discovery-route {
               uses common-route-parameters-grp; route-rd-rt-grp;
               leaf ethernet-segment-identifier {
                 type uint32;
                 description "Ethernet segment identifier (esi)";
               }
               leaf ethernet-tag {
                 type uint32;
                 description "An ethernet tag (etag) indentifying a " +
                             "broadcast domain";
               }
               list path {
                 uses next-hop-label-grp;
                 uses path-detail-grp;
                 description "path";
               }
               description "ethernet-auto-discovery-route";
             }
             list mac-ip-advertisement-route {
               uses common-route-parameters-grp; route-rd-rt-grp;
               leaf ethernet-segment-identifier {
                 type uint32;
                 description "Ethernet segment identifier (esi)";
               }
               leaf ethernet-tag {
                 type uint32;
                 description "An ethernet tag (etag) indentifying a " +
                             "broadcast domain";
               }
               leaf mac-address {
                 type yang:hex-string;
                 description "Route mac address";
               }
               leaf mac-address-length {
                 type uint8 {
                   range "0..48";
                 }
                 description "mac address length";
               }
               leaf ip-prefix {
                 type inet:ip-prefix;
                 description "ip-prefix";
               }
               list path {
                 uses next-hop-label-grp;
                 uses next-hop-label2-grp;
                 uses path-detail-grp;
                 description "path";
               }
               description "mac-ip-advertisement-route";
             }
             list inclusive-multicast-ethernet-tag-route {
               uses common-route-parameters-grp; route-rd-rt-grp;
               leaf ethernet-segment-identifier {
                 type uint32;
                 description "Ethernet segment identifier (esi)";
               }
               leaf originator-ip-prefix {
                 type inet:ip-prefix;
                 description "originator-ip-prefix";
               }
               list path {
                 uses next-hop-label-grp;
                 uses path-detail-grp;
                 description "path";
               }
               description "inclusive-multicast-ethernet-tag-route";
             }
             list ethernet-segment-route {
               uses common-route-parameters-grp; route-rd-rt-grp;
               leaf ethernet-segment-identifier {
                 type uint32;
                 description "Ethernet segment identifier (esi)";
               }
               leaf originator-ip-prefix {
                 type inet:ip-prefix;
                 description "originator ip-prefix";
               }
               list path {
                 leaf next-hop {
                   type inet:ip-address;
                   description "next-hop";
                 }
                 uses path-detail-grp;
                 description "path";
               }
               description "ethernet-segment-route";
             }
             list ip-prefix-route {
               uses common-route-parameters-grp; route-rd-rt-grp;
               leaf ethernet-segment-identifier {
                 type uint32;
                 description "Ethernet segment identifier (esi)";
               }
               leaf ip-prefix {
                 type inet:ip-prefix;
                 description "ip-prefix";
               }
               list path {
                 uses next-hop-label-grp;
                 uses path-detail-grp;
                 description "path";
               }
               description "ip-prefix route";
             }
           }
           container statistics {
             description "Statistics";
             leaf tx-count {
               type uint32;
               description "transmission count";
             }
             leaf rx-count {
               type uint32;
               description "receive count";
             }
             container detail {
               description "Detailed statistics";
               leaf broadcast-tx-count {
                 type uint32;
                 description "broadcast transmission count";
               }
               leaf broadcast-rx-count {
                 type uint32;
                 description "broadcast receive count";
               }
               leaf multicast-tx-count {
                 type uint32;
                 description "multicast transmission count";
               }
               leaf multicast-rx-count {
                 type uint32;
                 description "multicast receive count";
               }
               leaf unicast-tx-count {
                 type uint32;
                 description "unicast transmission count";
               }
               leaf unicast-rx-count {
                 type uint32;
                 description "unicast receive count";
               }
             }
           }
         }
       }
     }
     /* augments */
     augment "/l2vpn:l2vpn/l2vpn:l2vpn-instances" +
             "/l2vpn:l2vpn-instance" {
       description "Augment for an L2VPN instance and EVPN association";
       leaf evpn-instance {
         type evpn-instance-ref;
         description "Reference to an EVPN instance";
       }
     }

     augment "/l2vpn:l2vpn-state" {
       description "Augment for an L2VPN instance's operational " +
                   "state of L2VPN and EVPN association";
       leaf evpn-instance {
         type string;
         description "Name of the associated EVPN instance";
       }
     }
   }

   <CODE ENDS>

5. Security Considerations

      The configuration, state, action and notification data defined in
   this document are designed to be accessed via the NETCONF protocol
   [RFC6241].  The lowest NETCONF layer is the secure transport layer
   and the mandatory-to-implement secure transport is SSH [RFC6242]. The
   NETCONF access control model [RFC6536] provides means to restrict
   access for particular NETCONF users to a pre-configured subset of all
   available NETCONF protocol operations and content.

      The security concerns listed above are, however, no different than
   faced by other routing protocols. Hence, this draft does not change
   any underlying security issues inherent in [I-D.ietf-netmod-routing-
   cfg]

6. IANA Considerations

      None.

7. Acknowledgments

      The authors would like to acknowledge TBD for their useful
   comments.

8. References
8.1. Normative References

      [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
                 Requirement Levels", BCP 14, RFC 2119, March 1997.

8.2. Informative References
      [RFC6241]  R.Enns et al., "Network Configuration
                 Protocol (NETCONF)",
                 RFC 6241, June 2011

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

      [RFC6242]  M. Wasserman, "Using the NETCONF Protocol over
                 Secure Shell (SSH)",
                 RFC 6242, June 2011.

      [RFC6536]  A. Bierman et al., "Network Configuration Protocol
                 (NETCONF) Access Control Model"
                 RFC 6536, March 2012.

      [RFC7432]  Sajassi et al., "BGP MPLS-Based Ethernet VPN",
                 RFC 7432, February 2015.

      [RFC7623]  Sajassi et al., "Provider Backbone Bridging
                 Combined with Ethernet VPN (PBB-EVPN)",
                 RFC 7623, September 2015

Authors' Addresses

   Patrice Brissette
   Cisco Systems, Inc.
   EMail: pbrisset@cisco.com

   Ali Sajassi
   Cisco Systems, Inc.
   EMail: sajassi@cisco.com

   Himanshu Shah
   Ciena Corporation
   EMail: hshah@ciena.com

   Zhenbin Li
   Huawei Technologies
   EMail: lizhenbin@huawei.com

   Helen Chen
   Ericsson
   Jabil
   EMail: ichen@kuatrotech.com Ing-Wher_Chen@jabil.com

   Kishore Tiruveedhula
   Juniper Networks
   EMail: kishoret@juniper.net

   Iftekar Hussain
   Infinera Corporation
   EMail: ihussain@infinera.com

   Jorge Rabadan
   Nokia
   EMail: jorge.rabadan@nokia.com