MPLS Working Group                                               K. Raza
Internet-Draft                                           S. Krishnaswamy
Intended status: Standards Track                     Cisco Systems, Inc.
Expires: May 16, 2017
                                                                  X. Liu
                                                     Kuatro Technologies

                                                                S. Esale
                                                        Juniper Networks

                                                                 X. Chen
                                                     Huawei Technologies

                                                           Jeff Tantsura

                                                       November 12, 2016


                     YANG Data Model for MPLS mLDP
                      draft-ietf-mpls-mldp-yang-00

Abstract

   This document describes a YANG data model for Multi-Protocol Label
   Switching (MPLS) Multipoint Label Distribution Protocol (mLDP).  The
   mLDP data model augments the LDP data model.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on May 16, 2017.








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Copyright Notice

   Copyright (c) 2016 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Specification of Requirements . . . . . . . . . . . . . . . .   3
   3.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Configuration . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Configuration Hierarchy . . . . . . . . . . . . . . . . .   4
     4.2.  mldp container  . . . . . . . . . . . . . . . . . . . . .   6
     4.3.  Leveraging LDP containers . . . . . . . . . . . . . . . .   6
     4.4.  YANG tree . . . . . . . . . . . . . . . . . . . . . . . .   7
   5.  Operational State . . . . . . . . . . . . . . . . . . . . . .   9
     5.1.  Derived states  . . . . . . . . . . . . . . . . . . . . .  13
       5.1.1.  Root state  . . . . . . . . . . . . . . . . . . . . .  13
       5.1.2.  Bindings state  . . . . . . . . . . . . . . . . . . .  14
       5.1.3.  Capabilities state  . . . . . . . . . . . . . . . . .  18
   6.  Notifications . . . . . . . . . . . . . . . . . . . . . . . .  18
   7.  Actions . . . . . . . . . . . . . . . . . . . . . . . . . . .  18
   8.  Open Items  . . . . . . . . . . . . . . . . . . . . . . . . .  18
   9.  YANG Specification  . . . . . . . . . . . . . . . . . . . . .  19
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  43
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  43
   12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  44
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  44
     13.1.  Normative References . . . . . . . . . . . . . . . . . .  44
     13.2.  Informative References . . . . . . . . . . . . . . . . .  45
   Appendix A.  Additional Contributors  . . . . . . . . . . . . . .  46
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  46

1.  Introduction

   This document introduces a YANG data model for MPLS Multipoint Label
   Distribution Protocol (mLDP).  The mLDP model being defined here is
   highly dependent on LDP YANG data model



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   [I-D.ietf-mpls-ldp-mldp-yang].  This implies that an opertor will
   need to use base LDP module to configure and manage control plane for
   mLDP.  For example, an operator would enable LDP discovery on MPLS
   interface to establish LDP/mLDP peering on which mLDP bindings could
   be exchanged.  Similarly, an operator could query state information
   for an LDP peer in order to verify peering attributes etc.

   Moreover, it is important to note here that any assumptions made in
   the LDP model also hold true in this document, unless otherwise
   explicitly stated.

   This document specifies mLDP model under ietf-mpls-mldp that augments
   LDP model as defined under ietf-mpls-ldp
   [I-D.ietf-mpls-ldp-mldp-yang].  Like its base LDP data model, this
   model also defines the following constructs for managing the mLDP
   protocol:

   o  Configuration

   o  Operational State

   o  Executables (Actions)

   o  Notifications

   This document is organized to define the data model for each of the
   above constructs in the sequence as listed above.

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.  Overview

   Following are the main mLDP areas and features that are within the
   scope of this model:

   o  mLDP Base Specification [RFC6388]

   o  mLDP Recursive FEC [RFC6512]

   o  Targeted mLDP [RFC7060]

   o  mLDP Fast-Reroute (FRR):

      *  Node Protection [RFC7715]



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      *  Multicast-only

   o  In-band Signaling:

      *  mLDP In-band Signaling [RFC6826]

      *  mLDP In-band signaling in a VRF [RFC7246]

      *  mLDP In-band Signaling with Wildcards [RFC7438]

   o  Hub-and-Spoke Multipoint LSPs [RFC7140]

   o  Configured Leaf LSPs (manually provisioned)

   [Ed Note: Some of the topics in the above list are to be addressed/
   extended in a later revision of this document].

4.  Configuration

4.1.  Configuration Hierarchy

   In terms of overall configuration layout, following figure highlights
   extensions to LDP configuration model to incorporate mLDP:




























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    module: ietf-mpls-ldp
        augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol:
              +-- mpls-ldp
                  +-- global
                  |    +-- ...
                  |    +-- ...
                  |    +-- mldp (augmentation)
                  |    |   +-- ...
                  |    |   +-- ...
                  |    |   +-- address-family* [afi]
                  |    |       +-- ...
                  |    |       +-- ...
                  |    |       +-- configured-leaf-lsps
                  |    |           +-- p2mp
                  |    |           |   +-- ...
                  |    |           |   +-- ...
                  |    |           +-- mp2mp
                  |    |               +-- ...
                  |    |               +-- ...
                  |    +-- capability
                  |        +-- ...
                  |        +-- ...
                  |        +-- mldp (augmentation)
                  |            +-- ...
                  |            +-- ...
                  +-- peers
                       +-- ...
                       +-- ...
                       +-- peer*
                           +-- ...
                           +-- ...
                           +-- capability
                               +-- ...
                               +-- ...
                               +-- mldp
                                   +-- ...
                                   +-- ...


                                 Figure 1

   From above hierarchy, we can categorize mLDP configuration parameters
   into two types:

   o  Parameters that are mLDP specific

   o  Parameters that leverage/extend LDP containers and parameters




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   Following subsections first describe mLDP specific configuration
   parameters, followed by those leveraging LDP.

4.2.  mldp container

   mldp container is an augmentation of LDP global container and holds
   the configuration related to items that are mLDP specific.  The main
   items under this container are:

   o  mLDP enabling: To enable mLDP under a (VRF) routing instance, mldp
      container is enabled under LDP.  Given that mLDP requires LDP
      signalling, it is not sensible to allow disabling LDP control
      plane under a (VRF) network-instance while requiring mLDP to be
      enabled for the same.  However, if a user wants only to allow
      signalling for multipoint FECs on an LDP/mLDP enabled VRF
      instance, he/she can use LDP label-policies to disable unicast
      FECs under the VRF.

   o  mLDP per-AF features: mLDP manages its own list of IP address-
      families and the features enabled underneath.  The per-AF mLDP
      configuration items include:

      *  Multicast-only FRR: This enables Multicast-only FRR
         functionality for a given AF under mLDP.  The feature allows
         route-policy to be configured for finer control/applicability
         of the feature.

      *  Recursive FEC: The recursive-fec feature [RFC6512] can be
         enabled per AF with a route-policy.

      *  Configured Leaf LSPs: To provision multipoint leaf LSP
         manually, a container is provided per-AF under LDP.  The
         configuration is flexible and allows a user to specify MP LSPs
         of type p2mp or mp2mp with IPv4 or IPv6 root address(es) by
         using either LSP-Id or (S,G).

   Targeted mLDP feature specification [RFC7060] does not require any
   mLDP specific configuration.  It, however, requires LDP upstream-
   label-assignment capability [RFC6389] to be enabled.

4.3.  Leveraging LDP containers

   mLDP configuration model leverages following configuration areas and
   containers that are already defined for LDP:

   o  Capabilities: A new container "mldp" is defined that augments
      LDP's capabilities container.  This new container specifies any
      mLDP specific capabilities and their parameters.  Moreover, a new



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      "mldp" container is also added by augmenting LDP per-peer
      capability container to override/control mLDP specific
      capabilities on a peer level.  In the scope of this document, the
      most important capabilities related to mLDP are p2mp, mp2mp, make-
      before-break, hub-and-spoke, and node-protection.

   o  Discovery and Peer: mLDP requires LDP discovery and peer
      procedures to form mLDP peering.  A peer is treated as mLDP peer
      only when either P2MP or MP2MP capabilities have been successfully
      exchanged with the peer.  If a user wish to selectively enable or
      disable mLDP with a LDP-enabled peer, he/she may use per-peer mLDP
      capabilities configuration.  [Ed Note: The option to control mLDP
      enabling/disabling on a peer-list is being explored for future ].
      In most common deployments, it is desirable to disable mLDP
      (capabilities announcements) on a targeted-only LDP peering, where
      targeted-only peer is the one whose discovery sources are targeted
      type only.  In future revision, a configuration option for this
      support will also be provided.

   o  Forwarding: By default, mLDP is allowed to select any of the LDP
      enabled interface as a downstream interface towards a nexthop
      (LDP/mLDP peer) for MP LSP programming.  However, a configuration
      option is provided to allow mLDP to exclude a given interface from
      such a selection.  Note that such a configuration option will be
      useful only when there are more than one interfaces available for
      the downstream selection.

   This goes without saying that mLDP configuration tree follows the
   same approach as LDP, where the tree comprise leafs for intended
   configuration.

4.4.  YANG tree

   The following figure captures the YANG tree for mLDP configuration.


module: ietf-mpls-mldp

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global:
   +--rw mldp {mldp}?
      +--rw config
      |  +--rw enable?   boolean
      +--rw address-family* [afi]
         +--rw afi                     ldp:ldp-address-family
         +--rw config
         |  +--rw multicast-only-frr {mldp-mofrr}?
         |  |  +--rw prefix-list?   ldp:prefix-list-ref
         |  +--rw recursive-fec



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         |     +--rw prefix-list?   ldp:prefix-list-ref
         +--rw configured-leaf-lsps
            +--rw p2mp
            |  +--rw roots-ipv4
            |  |  +--rw root* [root-address]
            |  |     +--rw root-address    inet:ipv4-address
            |  |     +--rw lsp* [lsp-id source-address group-address]
            |  |        +--rw lsp-id            uint16
            |  |        +--rw source-address    inet:ipv4-address
            |  |        +--rw group-address     inet:ipv4-address-no-zone
            |  +--rw roots-ipv6
            |     +--rw root* [root-address]
            |        +--rw root-address    inet:ipv6-address
            |        +--rw lsp* [lsp-id source-address group-address]
            |           +--rw lsp-id            uint16
            |           +--rw source-address    inet:ipv6-address
            |           +--rw group-address     inet:ipv6-address-no-zone
            +--rw mp2mp
               +--rw roots-ipv4
               |  +--rw root* [root-address]
               |     +--rw root-address    inet:ipv4-address
               |     +--rw lsp* [lsp-id source-address group-address]
               |        +--rw lsp-id            uint16
               |        +--rw source-address    inet:ipv4-address
               |        +--rw group-address     inet:ipv4-address-no-zone
               +--rw roots-ipv6
                  +--rw root* [root-address]
                     +--rw root-address    inet:ipv6-address
                     +--rw lsp* [lsp-id source-address group-address]
                        +--rw lsp-id            uint16
                        +--rw source-address    inet:ipv6-address
                        +--rw group-address     inet:ipv6-address-no-zone

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global/ldp:config/ldp:capability:
   +--rw mldp
      +--rw p2mp
      |  +--rw enable?   boolean
      +--rw mp2mp
      |  +--rw enable?   boolean
      +--rw make-before-break
      |  +--rw enable?             boolean
      |  +--rw switchover-delay?   uint16
      |  +--rw timeout?            uint16
      +--rw hub-and-spoke {capability-mldp-hsmp}?
      |  +--rw enable?   boolean
      +--rw node-protection {capability-mldp-node-protection}?
         +--rw plr?           boolean
         +--rw merge-point



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            +--rw enable?                            boolean
            +--rw targeted-session-teardown-delay?   uint16

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global/ldp:forwarding-nexthop/ldp:interfaces/ldp:interface/ldp:address-family/ldp:config:
   +--rw mldp-disable?   boolean {mldp}?


augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:config/ldp:capability:
   +--rw mldp {mldp}?
      +--rw p2mp
      |  +--rw enable?   boolean
      +--rw mp2mp
      |  +--rw enable?   boolean
      +--rw make-before-break
      |  +--rw enable?             boolean
      |  +--rw switchover-delay?   uint16
      |  +--rw timeout?            uint16
      +--rw hub-and-spoke {capability-mldp-hsmp}?
      |  +--rw enable?   boolean
      +--rw node-protection {capability-mldp-node-protection}?
         +--rw plr?           boolean
         +--rw merge-point
            +--rw enable?                            boolean
            +--rw targeted-session-teardown-delay?   uint16


                                 Figure 2

5.  Operational State

   Operational state of mLDP can be queried and obtained from various
   read-only mdlp "state" containers that augment ldp state containers.

   Please note this state tree refers both the configuration "applied"
   state as well as the "derived" state related to the mLDP protocol.
   [Ed note: Future revision will realign]

   Following is a simplified graphical representation of the data model
   for mLDP operational state:


module: ietf-mpls-mldp

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global:
   +--rw mldp {mldp}?
      +--ro state
      |  +--ro enable?   boolean
      +--rw address-family* [afi]



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         +--ro state
            +--ro multicast-only-frr {mldp-mofrr}?
            |  +--ro prefix-list?   ldp:prefix-list-ref
            +--ro recursive-fec
            |  +--ro prefix-list?   ldp:prefix-list-ref
            +--ro ipv4
            |  +--ro roots
            |  |  +--ro root* [root-address]
            |  |     +--ro root-address    inet:ipv4-address
            |  |     +--ro is-self?        boolean
            |  |     +--ro reachability* [address interface]
            |  |        +--ro address      inet:ipv4-address
            |  |        +--ro interface    ldp:mpls-interface-ref
            |  |        +--ro peer?        leafref
            |  +--ro bindings
            |     +--ro opaque-type-lspid
            |     |  +--ro fec-label* [root-address lsp-id recur-root-address recur-rd]
            |     |     +--ro root-address          inet:ipv4-address
            |     |     +--ro lsp-id                uint32
            |     |     +--ro recur-root-address    inet:ip-address
            |     |     +--ro recur-rd              route-distinguisher
            |     |     +--ro multipoint-type?      multipoint-type
            |     |     +--ro peer* [direction peer advertisement-type]
            |     |        +--ro direction             ldp:downstream-upstream
            |     |        +--ro peer                  leafref
            |     |        +--ro advertisement-type    ldp:advertised-received
            |     |        +--ro label?                mpls:mpls-label
            |     |        +--ro mbb-role?             enumeration
            |     |        +--ro mofrr-role?           enumeration
            |     +--ro opaque-type-transit
            |     |  +--ro fec-label* [root-address source-address group-address ... ]
            |     |     +--ro root-address          inet:ipv4-address
            |     |     +--ro source-address        inet:ip-address
            |     |     +--ro group-address         inet:ip-address-no-zone
            |     |     +--ro rd                    route-distinguisher
            |     |     +--ro recur-root-address    inet:ip-address
            |     |     +--ro recur-rd              route-distinguisher
            |     |     +--ro multipoint-type?      multipoint-type
            |     |     +--ro peer* [direction peer advertisement-type]
            |     |        +--ro direction             ldp:downstream-upstream
            |     |        +--ro peer                  leafref
            |     |        +--ro advertisement-type    ldp:advertised-received
            |     |        +--ro label?                mpls:mpls-label
            |     |        +--ro mbb-role?             enumeration
            |     |        +--ro mofrr-role?           enumeration
            |     +--ro opaque-type-bidir
            |        +--ro fec-label* [root-address rp group-address ... ]
            |           +--ro root-address          inet:ipv4-address



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            |           +--ro rp                    inet:ip-address
            |           +--ro group-address         inet:ip-address-no-zone
            |           +--ro rd                    route-distinguisher
            |           +--ro recur-root-address    inet:ip-address
            |           +--ro recur-rd              route-distinguisher
            |           +--ro multipoint-type?      multipoint-type
            |           +--ro peer* [direction peer advertisement-type]
            |              +--ro direction             ldp:downstream-upstream
            |              +--ro peer                  leafref
            |              +--ro advertisement-type    ldp:advertised-received
            |              +--ro label?                mpls:mpls-label
            |              +--ro mbb-role?             enumeration
            |              +--ro mofrr-role?           enumeration
            +--ro ipv6
               +--ro roots
               |  +--ro root* [root-address]
               |     +--ro root-address    inet:ipv6-address
               |     +--ro is-self?        boolean
               |     +--ro reachability* [address interface]
               |        +--ro address      inet:ipv6-address
               |        +--ro interface    ldp:mpls-interface-ref
               |        +--ro peer?        leafref
               +--ro bindings
                  +--ro opaque-type-lspid
                  |  +--ro fec-label* [root-address lsp-id recur-root-address recur-rd]
                  |     +--ro root-address          inet:ipv6-address
                  |     +--ro lsp-id                uint32
                  |     +--ro recur-root-address    inet:ip-address
                  |     +--ro recur-rd              route-distinguisher
                  |     +--ro multipoint-type?      multipoint-type
                  |     +--ro peer* [direction peer advertisement-type]
                  |        +--ro direction             ldp:downstream-upstream
                  |        +--ro peer                  leafref
                  |        +--ro advertisement-type    ldp:advertised-received
                  |        +--ro label?                mpls:mpls-label
                  |        +--ro mbb-role?             enumeration
                  |        +--ro mofrr-role?           enumeration
                  +--ro opaque-type-transit
                  |  +--ro fec-label* [root-address source-address group-address ... ]
                  |     +--ro root-address          inet:ipv6-address
                  |     +--ro source-address        inet:ip-address
                  |     +--ro group-address         inet:ip-address-no-zone
                  |     +--ro rd                    route-distinguisher
                  |     +--ro recur-root-address    inet:ip-address
                  |     +--ro recur-rd              route-distinguisher
                  |     +--ro multipoint-type?      multipoint-type
                  |     +--ro peer* [direction peer advertisement-type]
                  |        +--ro direction             ldp:downstream-upstream



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                  |        +--ro peer                  leafref
                  |        +--ro advertisement-type    ldp:advertised-received
                  |        +--ro label?                mpls:mpls-label
                  |        +--ro mbb-role?             enumeration
                  |        +--ro mofrr-role?           enumeration
                  +--ro opaque-type-bidir
                     +--ro fec-label* [root-address rp group-address ... ]
                        +--ro root-address          inet:ipv6-address
                        +--ro rp                    inet:ip-address
                        +--ro group-address         inet:ip-address-no-zone
                        +--ro rd                    route-distinguisher
                        +--ro recur-root-address    inet:ip-address
                        +--ro recur-rd              route-distinguisher
                        +--ro multipoint-type?      multipoint-type
                        +--ro peer* [direction peer advertisement-type]
                           +--ro direction             ldp:downstream-upstream
                           +--ro peer                  leafref
                           +--ro advertisement-type    ldp:advertised-received
                           +--ro label?                mpls:mpls-label
                           +--ro mbb-role?             enumeration
                           +--ro mofrr-role?           enumeration


augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global/ldp:forwarding-nexthop/ldp:interfaces/ldp:interface/ldp:address-family/ldp:state:
   +--ro mldp-disable?   boolean {mldp}?

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:global/ldp:state/ldp:capability:
   +--ro mldp
      +--ro p2mp
      |  +--ro enable?   boolean
      +--ro mp2mp
      |  +--ro enable?   boolean
      +--ro make-before-break
      |  +--ro enable?             boolean
      |  +--ro switchover-delay?   uint16
      |  +--ro timeout?            uint16
      +--ro hub-and-spoke {capability-mldp-hsmp}?
      |  +--ro enable?   boolean
      +--ro node-protection {capability-mldp-node-protection}?
         +--ro plr?           boolean
         +--ro merge-point
            +--ro enable?                            boolean
            +--ro targeted-session-teardown-delay?   uint16

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:state/ldp:capability:
   +--ro mldp {mldp}?
      +--ro p2mp
      |  +--ro enable?   boolean



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      +--ro mp2mp
      |  +--ro enable?   boolean
      +--ro make-before-break
      |  +--ro enable?             boolean
      |  +--ro switchover-delay?   uint16
      |  +--ro timeout?            uint16
      +--ro hub-and-spoke {capability-mldp-hsmp}?
      |  +--ro enable?   boolean
      +--ro node-protection {capability-mldp-node-protection}?
         +--ro plr?           boolean
         +--ro merge-point
            +--ro enable?                            boolean
            +--ro targeted-session-teardown-delay?   uint16

augment /rt:routing/rt:control-plane-protocols/ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:state/ldp:received-peer-state/ldp:capability:
   +--ro mldp {mldp}?
      +--ro p2mp
      |  +--ro enable?   boolean
      +--ro mp2mp
      |  +--ro enable?   boolean
      +--ro make-before-break
      |  +--ro enable?   boolean
      +--ro hub-and-spoke
      |  +--ro enable?   boolean
      +--ro node-protection
         +--ro plr?           boolean
         +--ro merge-point?   boolean


                                 Figure 3

5.1.  Derived states

   Following are main areas for which mLDP operational derived state is
   defined:

   o  Root

   o  Bindings (FEC-label)

   o  Capabilities

5.1.1.  Root state

   Root address is a fundamental construct for MP FEC bindings and LSPs.
   The root state provides information on all the known roots in a given
   address-familty, and their information on the root reachability (as
   learnt from RIB).  In case of multi-path reachability to a root, the



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   selection of upstream path is done on per-LSP basis at the time of
   LSP setup.  Similarly, when protection mechanisms like MBB or MoFRR
   are in place, the path designation as active/standby or primary/
   backup is also done on per LSP basis.  It is to be noted that a given
   root can be shared amongst multiple P2MP and/or MP2MP LSPs.
   Moreover, an LSP can be signaled to more than one root for RNR
   purposes.

   The following diagram illustrates a root database on a branch/transit
   LSR:


        root 1.1.1.1:
            path1:
                RIB: GigEthernet 1/0, 12.1.0.2;
                LDP: peer 192.168.0.1:0
            path2:
                RIB: GigEthernet 2/0, 12.2.0.2;
                LDP: peer 192.168.0.3:0

        root 2.2.2.2:
            path1:
                RIB: 3.3.3.3;             (NOTE: This is a recursive path)
                LDP: peer 192.168.0.3:0   (NOTE: T-mLDP peer)

         root 9.9.9.9:
            . . . .


                                 Figure 4

   A root entry on a root LSR itself will be presented as follows:


           root 9.9.9.9:
               is-self


                                 Figure 5

5.1.2.  Bindings state

   Binding state provides information on mLDP FEC-label bindings for
   both P2MP and MP2MP FEC types.  Like LDP, the FEC-label binding
   derived state is presented in a FEC-centric view per address-family,
   and provides information on both inbound (received) and outbound
   (advertised) bindings.  The FEC is presented as (root-address,
   opaque-type-data) and the direction (upstream or downstream) is



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   picked with respect to root reachability.  In case of MBB or/and
   MoFRR, the role of a given peer binding is also provided with respect
   to MBB (active or standby) or/and MoFRR (primary or backup).

   This document covers following type of opaque values with their keys
   in the operational model of mLDP bindings:

       +-------------------------+--------------------+------------+
       | Opaque Type             | Key                | RFC        |
       +-------------------------+--------------------+------------+
       | Generic LSP Identifier  | LSP Id             | [RFC6388]  |
       | Transit IPv4 Source     | Source, Group      | [RFC6826]  |
       | Transit IPv6 Source     | Source, Group      | [RFC6826]  |
       | Transit IPv4 Bidir      | RP, Group          | [RFC6826]  |
       | Transit IPv6 Bidir      | RP, Group          | [RFC6826]  |
       | Transit VPNv4 Source    | Source, Group, RD  | [RFC7246]  |
       | Transit VPNv6 Source    | Source, Group, RD  | [RFC7246]  |
       | Transit VPNv4 Bidir     | RP, Group, RD      | [RFC7246]  |
       | Transit VPNv6 Bidir     | RP, Group, RD      | [RFC7246]  |
       | Recursive Opaque        | Root               | [RFC6512]  |
       | VPN-Recursive Opaque    | Root, RD           | [RFC6512]  |
       +-------------------------+--------------------+------------+

                     Table 1: MP Opaque Types and keys

   It is to be noted that there are three basic types (LSP Id, Source,
   and Bidir) and then there are variants (VPN, recursive, VPN-
   recursive) on top of these basic types.

   Following captures a high level tree hierarchy for mLDP bindings
   state:




















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       +--rw mldp  (augmentation of ldp:global)
         +--rw address-family* [afi]
            +--rw afi       address-family
            +--ro state
               +--ro ipv4 (or ipv6)
                  +--ro bindings
                     +--ro opaque-type-xxx [root-address, type-specific-key]
                        +--ro root-address
                        +--ro ...
                        +--ro recur-root-address    inet:ipv4-address
                        +--ro recur-rd              route-distinguisher
                        +--ro multipoint-type?      multipoint-type
                        +--ro peer* [direction peer advertisement-type]
                           +--ro direction             downstream-upstream
                           +--ro peer                  leafref
                           +--ro advertisement-type    advertised-received
                           +--ro label?                mpls:mpls-label
                           +--ro mbb-role?             enumeration
                           +--ro mofrr-role?           enumeration

                                 Figure 6

   In the above tree, the type-specific-key varies with the base type as
   listed in earlier Table 1.  For example, if the opaque type is
   Generic LSP Identifier, then the type-specific-key will be a uint32
   value corresponding to the LSP.  Please see the complete model for
   all other types.

   Moreover, the binding tree defines only three types of sub-trees
   (i.e. lspid, src, and bidir) which is able to map the respective
   variants (vpn, recursive, and vpn-recusrive) accordingly.  For
   example, the key for opaque-type-src is [R, S, G, rd, recur-R, recur-
   RD], where basic type will specify (R, S,G,-, -, -), VPN type will
   specify (R, S,G, rd, -, -), recursive type will specify [R, S,G, -,
   recur-R, -] and VPN-recursive type will specify [R, S,G, -, recur-R,
   recur-rd].

   It is important to take note of the following:

   o  The address-family ipv4/ipv4 applies to "root" address in the mLDP
      binding tree.  The other addresses (source, group, RP etc) do not
      have to be of the same address family type as the root.

   o  The "recur-root-address" field applies to Recursive opaque type,
      and (recur-root-address, recur-rd) fields applies to VPN-Recursive
      opaque types as defined in [RFC6512]





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   o  In case of a recursive FEC, the address-family of the recur-root-
      address could be different than the address-family of the root
      address of original encapsulated MP FEC

   The following diagram illustrates the FEC-label binding information
   structure for a P2MP (Transit IPv4 Source type) LSP on a branch/
   transit LSR:


            FEC (root 2.2.2.2, S=192.168.1.1, G=224.1.1.1):
              type: p2mp
              upstream:
                advertised:
                  peer 192.168.0.1:0, label 16000 (local)
              downstream:
                received:
                  peer 192.168.0.2:0, label 17000 (remote)
                  peer 192.168.0.3:0, label 18000  (remote)



                                 Figure 7

   The following diagram illustrates the FEC-label binding information
   structure for a similar MP2MP LSP on a branch/transit LSR:


         FEC (root 2.2.2.2, RP=192.168.9.9, G=224.1.1.1):
           type: mp2mp
           upstream:
             advertised:
               peer 192.168.0.1:0, label 16000 (local)
             received:
               peer 192.168.0.1:0, label 17000 (remote)
           downstream:
             advertised:
               peer 192.168.0.2:0, label 16001 (local), MBB role=active
               peer 192.168.0.3:0, label 16002 (local), MBB role=standby
             received:
               peer 192.168.0.2:0, label 17001 (remote)
               peer 192.168.0.3:0, label 18001 (remote)


                                 Figure 8







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5.1.3.  Capabilities state

   Like LDP, mLDP capabilities state comprise two types of information:

   o  global: augments ldp:global/ldp:state/ldp:capability.

   o  per-peer: augments ldp:peers/ldp:peer/ldp:state/ldp:capability

6.  Notifications

   mLDP notification module consists of notification related to changes
   in the operational state of an mLDP FEC.  Following is a simplified
   graphical representation of the data model for mLDP notifications:


   module: ietf-mpls-mldp
   notifications:
      +---n mpls-mldp-fec-event
         +--ro event-type?       ldp:oper-status-event-type
         +--ro tree-type?        multipoint-type
         +--ro root?             inet:ip-address
         +--ro (lsp-key-type)?
            +--:(lsp-id-based)
            |  +--ro lsp-id?           uint16
            +--:(source-group-based)
               +--ro source-address?   inet:ip-address
               +--ro group-address?    inet:ip-address


                                 Figure 9

7.  Actions

   Currently, no RPCs/actions are defined for mLDP.

8.  Open Items

   Following is a list of open items that are to be discussed and
   addressed in future revisions of this document:

   o  Revisit and cut down on the scope of the document and number of
      features it is trying to cover

   o  Split the model into a base and extended items

   o  Align operational state modeling with other routing protocols and
      [I-D.openconfig-netmod-opstate]




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   o  Specify default values for configuration parameters

   o  Add statistics for mLDP root LSPs and bindings

   o  Extend the "Configured Leaf LSPs" for various type of opaque-types

   o  Extend mLDP notifications for other types of opaque values as well

9.  YANG Specification

   Following is the actual YANG definition for mLDP constructs defined
   earlier in the document.



<CODE BEGINS> file "ietf-mpls-mldp@2016-11-01.yang" -->

module ietf-mpls-mldp {
  namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-mldp";
  prefix mldp;

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

  import ietf-routing {
    prefix "rt";
  }

  import ietf-mpls {
    prefix "mpls";
  }

  import ietf-mpls-ldp {
    prefix "ldp";
  }

  organization
    "IETF MPLS Working Group";
  contact
    "WG Web:   <http://tools.ietf.org/wg/mpls/>
     WG List:  <mailto:mpls@ietf.org>

     WG Chair: Loa Andersson
               <mailto:loa@pi.nu>

     WG Chair: Ross Callon
               <mailto:rcallon@juniper.net>



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     WG Chair: George Swallow
               <mailto:swallow.ietf@gmail.com>

     Editor:   Kamran Raza
               <mailto:skraza@cisco.com>

     Editor:   Rajiv Asati
               <mailto:rajiva@cisco.com>

     Editor:   Xufeng Liu
               <mailto:xliu@kuatrotech.com>

     Editor:   Santosh Esale
               <mailto:sesale@juniper.net>

     Editor:   Xia Chen
               <mailto:jescia.chenxia@huawei.com>

     Editor:   Himanshu Shah
               <mailto:hshah@ciena.com>

     Editor:   Sowmya Krishnaswamy
               <mailto:sowkrish@cisco.com>";

  description
    "This YANG module defines the essential components for the
     management of Multi-Protocol Label Switching (MPLS) Multipoint
     LDP (mLDP).";

  revision 2016-11-01 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: YANG Data Model for MPLS mLDP.";
  }

  /*
   * Features
   */

  feature capability-mldp-hsmp {
    description
      "This feature indicates that the system allows to configure
       mLDP hub-and-spoke-multipoint capability.";
  }

  feature capability-mldp-node-protection {
    description



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      "This feature indicates that the system allows to configure
       mLDP node-protection capability.";
  }

  feature mldp {
    description
      "This feature indicates that the system supports Multicast
       LDP (mLDP).";
  }

  feature mldp-mofrr {
    description
      "This feature indicates that the system supports mLDP
       Multicast only FRR (MoFRR).";
  }

  /*
   * Typedefs
   */
  typedef multipoint-type {
    type enumeration {
      enum p2mp {
        description "Point to multipoint.";
      }
      enum mp2mp {
        description "Multipoint to multipoint.";
      }
    }
    description
      "p2mp or mp2mp.";
  }

  typedef route-distinguisher {
    type string {
    }
    description
      "Type definition for route distinguisher.";
    reference
      "RFC4364: BGP/MPLS IP Virtual Private Networks (VPNs).";
  }

  /*
   * Groupings
   */

  grouping mldp-capabilities {
    description
      "mLDP capabilities.";



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    container p2mp {
      description
        "Configure point-to-multipoint capability.";
      leaf enable {
        type boolean;
        description
          "Enable point-to-multipoint.";
      }
    }
    container mp2mp {
      description
        "Configure multipoint-to-multipoint capability.";
      leaf enable {
        type boolean;
        description
          "Enable multipoint-to-multipoint.";
      }
    }
    container make-before-break {
      description
        "Configure make-before-break capability.";
      leaf enable {
        type boolean;
        description
          "Enable make-before-break.";
      }
      leaf switchover-delay {
        type uint16;
        units seconds;
        description
          "Switchover delay in seconds.";
      }
      leaf timeout {
        type uint16;
        units seconds;
        description
          "Timeout in seconds.";
      }
    }
    container hub-and-spoke {
      if-feature capability-mldp-hsmp;
      description
        "Configure hub-and-spoke-multipoint capability.";
      reference
        "RFC7140: LDP Extensions for Hub and Spoke Multipoint
         Label Switched Path";
      leaf enable {
        type boolean;



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        description
          "Enable hub-and-spoke-multipoint.";
      }
    }
    container node-protection {
      if-feature capability-mldp-node-protection;
      description
        "Configure node-protection capability.";
      reference
        "RFC7715: mLDP Node Protection.";
      leaf plr {
        type boolean;
        description
          "Point of Local Repair capable for MP LSP node
           protection.";
      }
      container merge-point {
        description
          "Merge Point capable for MP LSP node protection.";
        leaf enable {
          type boolean;
          description
            "Enable merge point capability.";
        }
        leaf targeted-session-teardown-delay {
          type uint16;
          units seconds;
          description
            "Targeted session teardown delay.";
        }
      } // merge-point
    }
  } // mldp-capabilities

  grouping  mldp-configured-lsp-roots {
    description
      "mLDP roots containers.";

    container roots-ipv4 {

      when "../../../afi = 'ipv4'" {
        description
          "Only for IPv4.";
      }
      description
        "Configured IPv4 multicast LSPs.";
      list root {
        key "root-address";



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        description
          "List of roots for configured multicast LSPs.";

        leaf root-address {
          type inet:ipv4-address;
          description
            "Root address.";
        }

        list lsp {
          must "(lsp-id = 0 and source-address != '0.0.0.0' and "
            + "group-address != '0.0.0.0') or "
            + "(lsp-id != 0 and source-address = '0.0.0.0' and "
            + "group-address = '0.0.0.0')" {
            description
              "A LSP can be identified by either <lsp-id> or
               <source-address, group-address>.";
          }
          key "lsp-id source-address group-address";
          description
            "List of LSPs.";
          leaf lsp-id {
            type uint16;
            description "ID to identify the LSP.";
          }
          leaf source-address {
            type inet:ipv4-address;
            description
              "Source address.";
          }
          leaf group-address {
            type inet:ipv4-address-no-zone;
            description
              "Group address.";
          }
        } // list lsp
      } // list root
    } // roots-ipv4

    container roots-ipv6 {

      when "../../../afi = 'ipv6'" {
        description
          "Only for IPv6.";
      }
      description
        "Configured IPv6 multicast LSPs.";




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      list root {
        key "root-address";
        description
          "List of roots for configured multicast LSPs.";

        leaf root-address {
          type inet:ipv6-address;
          description
            "Root address.";
        }

        list lsp {
          must "(lsp-id = 0 and source-address != '::' and "
            + "group-address != '::') or "
            + "(lsp-id != 0 and source-address = '::' and "
            + "group-address = '::')" {
            description
              "A LSP can be identified by either <lsp-id> or
               <source-address, group-address>.";
          }
          key "lsp-id source-address group-address";
          description
            "List of LSPs.";
          leaf lsp-id {
            type uint16;
            description "ID to identify the LSP.";
          }
          leaf source-address {
            type inet:ipv6-address;
            description
              "Source address.";
          }
          leaf group-address {
            type inet:ipv6-address-no-zone;
            description
              "Group address.";
          }
        } // list lsp
      } // list root
    } // roots-ipv6
  } // mldp-configured-lsp-roots

  grouping mldp-fec-event {
    description
      "A mLDP FEC event.";
    leaf tree-type {
      type multipoint-type;
      description



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        "p2mp or mp2mp.";
    }
    leaf root {
      type inet:ip-address;
      description
        "Root address.";
    }
    choice lsp-key-type {
      description
        "LSP ID based or source-group based .";
      case lsp-id-based {
        leaf lsp-id {
          type uint16;
          description
            "ID to identify the LSP.";
        }
      }
      case source-group-based {
        leaf source-address {
          type inet:ip-address;
          description

            "LSP source address.";
        }
        leaf group-address {
          type inet:ip-address;
          description
            "Multicast group address.";
        }
      } // case source-group-based
    }
  } // mldp-fec-event

  grouping  mldp-binding-label-state-attributes {
    description
      "mLDP label binding attributes.";

    leaf multipoint-type {
      type multipoint-type;
      description
        "The type of mutipoint, p2mp or mp2mp.";
    }
    list peer {
      key "direction peer advertisement-type";
      description
        "List of advertised and received peers.";
      leaf direction {
        type ldp:downstream-upstream;



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        description
          "Downstream or upstream.";
      }
      leaf peer {
        type leafref {
          path
            "../../../../../../../../../../ldp:peers/ldp:peer/ldp:lsr-id";
        }
        description
          "LDP peer from which this binding is received,
           or to which this binding is advertised.";
      }
      leaf advertisement-type {
        type ldp:advertised-received;
        description
          "Advertised or received.";
      }
      leaf label {
        type mpls:mpls-label;
        description
          "Advertised (outbound) or received (inbound) label.";
      }
      leaf mbb-role {
        when "../direction = 'upstream'" {
          description
            "For upstream.";
        }
        type enumeration {
          enum none {
            description "MBB is not enabled.";
          }
          enum active {
            description "This LSP is active.";
          }
          enum inactive {
            description "This LSP is inactive.";
          }
        }
        description
          "The MBB status of this LSP.";
      }
      leaf mofrr-role {
        when "../direction = 'upstream'" {
          description
            "For upstream.";
        }
        type enumeration {
          enum none {



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            description "MOFRR is not enabled.";
          }
          enum primary {
            description "This LSP is primary.";
          }
          enum backup {
            description "This LSP is backup.";
          }
        }
        description
          "The MOFRR status of this LSP.";
      }
    } // peer
  } // mldp-binding-label-state-attributes

  /*
   * Configuration data nodes
   */
  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:global/ldp:config/ldp:capability" {
    description "Augmentation for MLDP global capability.";
    container mldp {
      description
        "Multipoint capabilities.";
      uses mldp-capabilities;
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:config/ldp:capability" {
    description "Augmentation for MLDP peer capability.";
    container mldp {
      if-feature mldp;
      description
        "mLDP capabilities.";
      uses mldp-capabilities;
    }
  }


  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:global/ldp:forwarding-nexthop/"
    + "ldp:interfaces/ldp:interface/ldp:address-family/"
    + "ldp:config" {
    description
      "Augmentation for MLDP nexthop forwarding interface.";
    leaf mldp-disable {
      if-feature mldp;



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      type boolean;
      description
        "Disable mLDP forwarding on the interface.";
    }
  }

  /*
   * Operational state data nodes
   */
  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:global/ldp:state/ldp:capability" {
    description "Augmentation for MLDP global capability.";
    container mldp {
      description
        "Multipoint capabilities.";
      uses mldp-capabilities;
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:state/ldp:capability" {
    description "Augmentation for MLDP peer capability.";
    container mldp {
      if-feature mldp;
      description
        "mLDP capabilities.";
      uses mldp-capabilities;
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:peers/ldp:peer/ldp:state/"
    + "ldp:received-peer-state/ldp:capability" {
    description
      "Augmentation for MLDP received peer state capability.";
    container mldp {
      if-feature mldp;
      description
        "Multipoint capabilities.";

      container p2mp {
        description
          "Configure point-to-multipoint capability.";
        leaf enable {
          type boolean;
          description
            "Enable point-to-multipoint.";
        }



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      }
      container mp2mp {
        description
          "Configure multipoint-to-multipoint capability.";
        leaf enable {
          type boolean;
          description
            "Enable multipoint-to-multipoint.";
        }
      }
      container make-before-break {
        description
          "Configure make-before-break capability.";
        leaf enable {
          type boolean;
          description
            "Enable make-before-break.";
        }
      }
      container hub-and-spoke {
        description
          "Configure hub-and-spoke-multipoint capability.";
        reference
          "RFC7140: LDP Extensions for Hub and Spoke Multipoint
           Label Switched Path";
        leaf enable {
          type boolean;
          description
            "Enable hub-and-spoke-multipoint.";
        }
      }
      container node-protection {
        description
          "Configure node-protection capability.";
        reference
          "RFC7715: mLDP Node Protection.";
        leaf plr {
          type boolean;
          description
            "Point of Local Repair capable for MP LSP node
             protection.";
        }
        leaf merge-point {
          type boolean;
          description
            "Merge Point capable for MP LSP node protection.";
        } // merge-point
      } // node-protection



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    } // mldp
  }

  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:global/ldp:forwarding-nexthop/"
    + "ldp:interfaces/ldp:interface/ldp:address-family/"
    + "ldp:state" {
    description
      "Augmentation for MLDP nexthop forwarding interface.";
    leaf mldp-disable {
      if-feature mldp;
      type boolean;
      description
        "Disable mLDP forwarding on the interface.";
    }
  }


  /*
   * Global augmentation
   */
  augment "/rt:routing/rt:control-plane-protocols/"
    + "ldp:mpls-ldp/ldp:global" {
    description "MLDP global augmentation.";
    container mldp {
      if-feature mldp;
      description
        "mLDP attributes at per instance level. Defining
         attributes here does not enable any MP capabilities.
         MP capabilities need to be explicitly enabled under
         container capability.";

      container config {
        description
          "Configuration data.";
        leaf enable {
          type boolean;
          description
            "Enable mLDP.";
        }
      }
      container state {
        config false;
        description

          "Operational state data.";
        leaf enable {
          type boolean;



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          description
            "Enable mLDP.";
        }
      }

      list address-family {
        key "afi";
        description
          "Per-af params.";
        leaf afi {
          type ldp:ldp-address-family;
          description
            "Address family type value.";
        }

        container config {
          description
            "Configuration data.";
          container multicast-only-frr {
            if-feature mldp-mofrr;
            description
              "Multicast only FRR (MoFRR) policy.";
            leaf prefix-list {
              type ldp:prefix-list-ref;
              description
                "Enables MoFRR for the specified access list.";
            }
          } // multicast-only-frr
          container recursive-fec {
            description
              "Recursive FEC policy.";
            leaf prefix-list {
              type ldp:prefix-list-ref;
              description
                "Enables recursive FEC for the specified access
                 list.";
            }
          } // recursive-for
        }
        container state {
          config false;
          description
            "Operational state data.";
          container multicast-only-frr {
            if-feature mldp-mofrr;

            description
              "Multicast only FRR (MoFRR) policy.";



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            leaf prefix-list {
              type ldp:prefix-list-ref;
              description
                "Enables MoFRR for the specified access list.";
            }
          } // multicast-only-frr
          container recursive-fec {
            description
              "Recursive FEC policy.";
            leaf prefix-list {
              type ldp:prefix-list-ref;
              description
                "Enables recursive FEC for the specified access
                 list.";
            }
          } // recursive-fec

          container ipv4 {
            when "../../afi = 'ipv4'" {
              description
                "Only for IPv4.";
            }
            description
              "IPv4 state information.";
            container roots {
              description
                "IPv4 multicast LSP roots.";
              list root {
                key "root-address";
                description
                  "List of roots for configured multicast LSPs.";

                leaf root-address {
                  type inet:ipv4-address;
                  description
                    "Root address.";
                }

                leaf is-self {
                  type boolean;
                  description
                    "This is the root.";
                }

                list reachability {
                  key "address interface";
                  description
                    "A next hop for reachability to root,



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                     as a RIB view.";
                  leaf address {
                    type inet:ipv4-address;
                    description
                      "The next hop address to reach root.";
                  }
                  leaf interface {
                    type ldp:mpls-interface-ref;
                    description
                      "Interface connecting to next-hop.";
                  }
                  leaf peer {
                    type leafref {
                      path
                        "../../../../../../../../../ldp:peers/"
                        + "ldp:peer/ldp:lsr-id";
                    }
                    description
                      "LDP peer from which this next hop can be
                           reached.";
                  }
                }
              } // list root
            } // roots
            container bindings {
              description
                "mLDP FEC to label bindings.";
              container opaque-type-lspid {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6388: Label Distribution Protocol
                   Extensions for Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key
                    "root-address lsp-id "
                    + "recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv4-address;
                    description
                      "Root address.";
                  }
                  leaf lsp-id {



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                    type uint32;
                    description "ID to identify the LSP.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label
              } // opaque-type-lspid

              container opaque-type-transit {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6826: Multipoint LDP In-Band Signaling for
                   Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key
                    "root-address source-address group-address "
                    + "rd recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv4-address;
                    description
                      "Root address.";
                  }
                  leaf source-address {
                    type inet:ip-address;
                    description
                      "Source address.";



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                  }
                  leaf group-address {
                    type inet:ip-address-no-zone;
                    description
                      "Group address.";
                  }
                  leaf rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher.";
                    reference
                      "RFC7246: Multipoint Label Distribution
                       Protocol In-Band Signaling in a Virtual
                       Routing and Forwarding (VRF) Table
                       Context.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label
              } // opaque-type-transit

              container opaque-type-bidir {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6826: Multipoint LDP In-Band Signaling for
                   Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key



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                    "root-address rp group-address "
                    + "rd recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv4-address;
                    description
                      "Root address.";
                  }
                  leaf rp {
                    type inet:ip-address;
                    description
                      "RP address.";
                  }
                  leaf group-address {
                    type inet:ip-address-no-zone;
                    description
                      "Group address.";
                  }
                  leaf rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher.";
                    reference
                      "RFC7246: Multipoint Label Distribution
                       Protocol In-Band Signaling in a Virtual
                       Routing and Forwarding (VRF) Table
                       Context.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label



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              } // opaque-type-bidir
            } // bindings
          } // ipv4

          container ipv6 {
            when "../../afi = 'ipv6'" {
              description
                "Only for IPv6.";
            }
            description
              "IPv6 state information.";
            container roots {
              description
                "IPv6 multicast LSP roots.";
              list root {
                key "root-address";
                description
                  "List of roots for configured multicast LSPs.";

                leaf root-address {
                  type inet:ipv6-address;
                  description
                    "Root address.";
                }

                leaf is-self {
                  type boolean;
                  description
                    "This is the root.";
                }

                list reachability {
                  key "address interface";
                  description
                    "A next hop for reachability to root,
                     as a RIB view.";
                  leaf address {
                    type inet:ipv6-address;
                    description
                      "The next hop address to reach root.";
                  }
                  leaf interface {
                    type ldp:mpls-interface-ref;
                    description
                      "Interface connecting to next-hop.";
                  }
                  leaf peer {
                    type leafref {



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                      path
                        "../../../../../../../../../ldp:peers/"
                        + "ldp:peer/ldp:lsr-id";
                    }
                    description
                      "LDP peer from which this next hop can be
                       reached.";
                  }
                }
              } // list root
            } // roots
            container bindings {
              description
                "mLDP FEC to label bindings.";
              container opaque-type-lspid {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6388: Label Distribution Protocol
                   Extensions for Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key
                    "root-address lsp-id "
                    + "recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv6-address;
                    description
                      "Root address.";
                  }
                  leaf lsp-id {
                    type uint32;
                    description "ID to identify the LSP.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;



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                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label
              } // opaque-type-lspid

              container opaque-type-transit {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6826: Multipoint LDP In-Band Signaling for
                   Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key
                    "root-address source-address group-address "
                    + "rd recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv6-address;
                    description
                      "Root address.";
                  }
                  leaf source-address {
                    type inet:ip-address;
                    description
                      "Source address.";
                  }
                  leaf group-address {
                    type inet:ip-address-no-zone;
                    description
                      "Group address.";
                  }
                  leaf rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher.";
                    reference
                      "RFC7246: Multipoint Label Distribution
                       Protocol In-Band Signaling in a Virtual



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                       Routing and Forwarding (VRF) Table
                       Context.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label
              } // opaque-type-transit

              container opaque-type-bidir {
                description
                  "The type of opaque value element is
                   the generic LSP identifier";
                reference
                  "RFC6826: Multipoint LDP In-Band Signaling for
                   Point-to-Multipoint and
                   Multipoint-to-Multipoint Label Switched
                   Paths.";
                list fec-label {
                  key
                    "root-address rp group-address "
                    + "rd recur-root-address recur-rd";
                  description
                    "List of FEC to label bindings.";
                  leaf root-address {
                    type inet:ipv6-address;
                    description
                      "Root address.";
                  }
                  leaf rp {
                    type inet:ip-address;
                    description
                      "RP address.";



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                  }
                  leaf group-address {
                    type inet:ip-address-no-zone;
                    description
                      "Group address.";
                  }
                  leaf rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher.";
                    reference
                      "RFC7246: Multipoint Label Distribution
                       Protocol In-Band Signaling in a Virtual
                       Routing and Forwarding (VRF) Table
                       Context.";
                  }
                  leaf recur-root-address {
                    type inet:ip-address;
                    description
                      "Recursive root address.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  leaf recur-rd {
                    type route-distinguisher;
                    description
                      "Route Distinguisher in the VPN-Recursive
                       Opaque Value.";
                    reference
                      "RFC6512: Using Multipoint LDP When the
                       Backbone Has No Route to the Root";
                  }
                  uses mldp-binding-label-state-attributes;
                } // fec-label
              } // opaque-type-bidir
            } // bindings
          } // ipv6
        } // state

        container configured-leaf-lsps {
          description
            "Configured multicast LSPs.";

          container p2mp {
            description
              "Configured point-to-multipoint LSPs.";
            uses mldp-configured-lsp-roots;



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          }
          container mp2mp {
            description
              "Configured multipoint-to-multipoint LSPs.";
            uses mldp-configured-lsp-roots;
          }
        } // configured-leaf-lsps
      } // list address-family
    } // mldp
  }

  /*
   * Notifications
   */
  notification mpls-mldp-fec-event {
    description
      "Notification event for a change of FEC status.";
    leaf event-type {
      type ldp:oper-status-event-type;
      description "Event type.";
    }
    uses mldp-fec-event;
  }
}

<CODE ENDS>



                                 Figure 10

10.  Security Considerations

   This mLDP model shares the same security considerations as captured
   in LDP Yang model [I-D.ietf-mpls-ldp-mldp-yang].

11.  IANA Considerations

   This document does not extend mLDP protocol specifiction and hence
   there are no IANA considerations.

   Note to the RFC Editor: Please remove IANA section before the
   publication.








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12.  Acknowledgments

   The authors would like to acknowledge Ladislav Lhotka for his useful
   comments as the YANG Doctor.

13.  References

13.1.  Normative References

   [I-D.ietf-mpls-ldp-mldp-yang]
              Raza, K., Asati, R., Liu, X., Esale, S., Chen, X., and H.
              Shah, "YANG Data Model for MPLS LDP and mLDP", draft-ietf-
              mpls-ldp-mldp-yang-00 (work in progress), August 2016.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC5036]  Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed.,
              "LDP Specification", RFC 5036, DOI 10.17487/RFC5036,
              October 2007, <http://www.rfc-editor.org/info/rfc5036>.

   [RFC5561]  Thomas, B., Raza, K., Aggarwal, S., Aggarwal, R., and JL.
              Le Roux, "LDP Capabilities", RFC 5561,
              DOI 10.17487/RFC5561, July 2009,
              <http://www.rfc-editor.org/info/rfc5561>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <http://www.rfc-editor.org/info/rfc6241>.

   [RFC6388]  Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B.
              Thomas, "Label Distribution Protocol Extensions for Point-
              to-Multipoint and Multipoint-to-Multipoint Label Switched
              Paths", RFC 6388, DOI 10.17487/RFC6388, November 2011,
              <http://www.rfc-editor.org/info/rfc6388>.

   [RFC6389]  Aggarwal, R. and JL. Le Roux, "MPLS Upstream Label
              Assignment for LDP", RFC 6389, DOI 10.17487/RFC6389,
              November 2011, <http://www.rfc-editor.org/info/rfc6389>.




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   [RFC6512]  Wijnands, IJ., Rosen, E., Napierala, M., and N. Leymann,
              "Using Multipoint LDP When the Backbone Has No Route to
              the Root", RFC 6512, DOI 10.17487/RFC6512, February 2012,
              <http://www.rfc-editor.org/info/rfc6512>.

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012,
              <http://www.rfc-editor.org/info/rfc6536>.

   [RFC6826]  Wijnands, IJ., Ed., Eckert, T., Leymann, N., and M.
              Napierala, "Multipoint LDP In-Band Signaling for Point-to-
              Multipoint and Multipoint-to-Multipoint Label Switched
              Paths", RFC 6826, DOI 10.17487/RFC6826, January 2013,
              <http://www.rfc-editor.org/info/rfc6826>.

   [RFC7060]  Napierala, M., Rosen, E., and IJ. Wijnands, "Using LDP
              Multipoint Extensions on Targeted LDP Sessions", RFC 7060,
              DOI 10.17487/RFC7060, November 2013,
              <http://www.rfc-editor.org/info/rfc7060>.

   [RFC7140]  Jin, L., Jounay, F., Wijnands, IJ., and N. Leymann, "LDP
              Extensions for Hub and Spoke Multipoint Label Switched
              Path", RFC 7140, DOI 10.17487/RFC7140, March 2014,
              <http://www.rfc-editor.org/info/rfc7140>.

   [RFC7246]  Wijnands, IJ., Ed., Hitchen, P., Leymann, N., Henderickx,
              W., Gulko, A., and J. Tantsura, "Multipoint Label
              Distribution Protocol In-Band Signaling in a Virtual
              Routing and Forwarding (VRF) Table Context", RFC 7246,
              DOI 10.17487/RFC7246, June 2014,
              <http://www.rfc-editor.org/info/rfc7246>.

   [RFC7438]  Wijnands, IJ., Ed., Rosen, E., Gulko, A., Joorde, U., and
              J. Tantsura, "Multipoint LDP (mLDP) In-Band Signaling with
              Wildcards", RFC 7438, DOI 10.17487/RFC7438, January 2015,
              <http://www.rfc-editor.org/info/rfc7438>.

   [RFC7715]  Wijnands, IJ., Ed., Raza, K., Atlas, A., Tantsura, J., and
              Q. Zhao, "Multipoint LDP (mLDP) Node Protection",
              RFC 7715, DOI 10.17487/RFC7715, January 2016,
              <http://www.rfc-editor.org/info/rfc7715>.

13.2.  Informative References







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   [I-D.ietf-rtgwg-policy-model]
              Shaikh, A., Shakir, R., D'Souza, K., and C. Chase,
              "Routing Policy Configuration Model for Service Provider
              Networks", draft-ietf-rtgwg-policy-model-01 (work in
              progress), April 2016.

   [I-D.iwijnand-mpls-mldp-multi-topology]
              Wijnands, I. and K. Raza, "mLDP Extensions for Multi
              Topology Routing", draft-iwijnand-mpls-mldp-multi-
              topology-03 (work in progress), June 2013.

   [I-D.openconfig-netmod-opstate]
              Shakir, R., Shaikh, A., and M. Hines, "Consistent Modeling
              of Operational State Data in YANG", draft-openconfig-
              netmod-opstate-01 (work in progress), July 2015.

Appendix A.  Additional Contributors

   Danial Johari
   Cisco Systems Inc.
   Email: dajohari@cisco.com

   Matthew Bocci
   Alcatel-Lucent
   matthew.bocci@alcatel-lucent.com

Authors' Addresses

   Kamran Raza
   Cisco Systems, Inc.
   Email: skraza@cisco.com


   Rajiv Asati
   Cisco Systems, Inc.
   Email: rajiva@cisco.com


   Sowmya Krishnaswamy
   Cisco Systems, Inc.
   Email: sowkrish@cisco.com


   Xufeng Liu
   Kuatro Technologies
   Email: xliu@kuatrotech.com







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   Jeff Tantsura
   Email: jefftant@gmail.com


   Santosh Esale
   Juniper Networks
   Email: sesale@juniper.net


   Xia Chen
   Huawei Technologies
   Email: jescia.chenxia@huawei.com


   Loa Andersson
   Huawei Technologies
   Email: loa@pi.nu


   Himanshu Shah
   Ciena Corporation
   Email: hshah@ciena.com
























Raza, et al.              Expires May 16, 2017                 [Page 47]