ISIS Working Group                                          S. Litkowski
Internet-Draft                                                    Orange
Intended status: Standards Track                                D. Yeung
Expires: April 27, September 5, 2015                                     A. Lindem
                                                           Cisco Systems
                                                                J. Zhang
                                                        Juniper Networks
                                                               L. Lhotka

                                                        October 24, 2014
                                                          March 04, 2015

                   YANG Data Model for ISIS protocol
                    draft-ietf-isis-yang-isis-cfg-01
                    draft-ietf-isis-yang-isis-cfg-02

Abstract

   This document defines a YANG data model that can be used to configure
   and manage ISIS protocol. protocol on network elements.

Requirements Language

   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].

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 April 27, September 5, 2015.

Copyright Notice

   Copyright (c) 2014 2015 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
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   to this document.  Code Components extracted from this document must
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Tree diagram  . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Design of the Data Model  . . . . . . . . . . . . . . . . . .   3
     2.1.  ISIS Configuration  . . . . . . . . . . . . . . . . . . .   8   5
     2.2.  Multitopology Parameters  . . . . . . . . . . . . . . . .   9   7
     2.3.  Per-Level Parameters  . . . . . . . . . . . . . . . . . .  10   7
     2.4.  Per-Interface Parameters  . . . . . . . . . . . . . . . .  10   8
     2.5.  ISO parameters  . . . . . . . . . . . . . . . . . . . . .  10
     2.6.  IP FRR  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     2.7.  Segment Routing . . . . . . . . . . . . . . . . . . . . .  10
     2.8.  Operational State . . . . . . . . . . . . . . . . . . . .  11
   3.  RPC Operations  . . . . . . . . . . . . . . . . . . . . . . .  15  18
   4.  Notifications . . . . . . . . . . . . . . . . . . . . . . . .  16  19
   5.  Interaction with Other YANG Modules . . . . . . . . . . . . .  20  23
   6.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .  20  23
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  82 110
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  83 111
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  83 112
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  83 112
   11. Normative References  . . . . . . . . . . . . . . . . . . . .  83 112
   Appendix A.  Example: NETCONF <get> Reply . . . . . . . . . . . .  84 112
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  87 115

1.  Introduction

   This document defines a YANG data model for ISIS routing protocol.

   The data model covers configuration of an ISIS routing protocol
   instance as well as operational states.

1.1.  Tree diagram

   A simplified graphical representation of the data model is presented
   in Section 2.

   The meaning of the symbols in these diagrams is as follows:

   o  Brackets "[" and "]" enclose list keys.

   o  Curly braces "{" and "}" contain names of optional features that
      make the corresponding node conditional.

   o  Abbreviations before data node names: "rw" means configuration
      (read-write), and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node and "*"
      denotes a "list" or "leaf-list".

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

2.  Design of the Data Model

   The ISIS YANG module is divided in two main containers "isis" containers that
   are augmenting the "routing-protocol" lists in ietf-routing module
   with specific ISIS parameters.

   One container contains the writable parameters, while the other
   contains the operational states.

   The figure below describe the overall structure of the isis YANG
   module:

module: ietf-isis
augment /rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route:
   +--ro metric?       uint32
   +--ro tag*          uint64
   +--ro route-type?   enumeration
   +--ro segment-id?   uint32 {segment-routing}?
augment /rt:active-route/rt:output/rt:route:
   +--ro metric?       uint32
   +--ro tag*          uint64
   +--ro route-type?   enumeration
   +--ro segment-id?   uint32 {segment-routing}?
augment /if:interfaces/if:interface:
   +--rw clns-mtu?   uint16
augment /rt:routing/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--rw isis
      +--rw instance* [routing-instance]
         +--rw routing-instance          rt:routing-instance-ref
         +--rw level-type?               level
         +--rw system-id?                system-id
         +--rw maximum-area-addresses?   uint8 {maximum-area-addresses}?
         +--rw area-address*             area-address
         +--rw mpls-te mpls
         |     ...
         +--rw reference-bandwidth?      uint32 {reference-bandwidth}?
         +--rw lsp-mtu?                  uint16
         +--rw lsp-lifetime?             uint16
         +--rw lsp-refresh?              uint16 {lsp-refresh}?
         +--rw graceful-restart {graceful-restart}?
         |     ...
         +--rw node-tag {node-tag}?
         |     ...
         +--rw fast-reroute {fast-reroute}?
         |     ...
         +--rw segment-routing {segment-routing}?
         |     ...
         +--rw authentication* [level]
         |     ...
         +--rw metric-type* [level]
         |     ...
         +--rw preference* [level]
         |     ...
         +--rw default-metric* [level]
         |     ...
         +--rw af* [af] {nlpid-control}?
         |     ...
         +--rw topologies* [name] {multi-topology}?
         |     ...
         +--rw overload* [level]
         |     ...
         +--rw overload-max-metric* [level] {overload-max-metric}?
         |     ...
         +--rw interfaces
               ...
augment /rt:routing-state/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--ro isis
      +--ro system-counters
      |  +--ro level* [level]
      |        ... instance* [routing-instance]
         +--ro interface-counters
      | routing-instance    rt:routing-instance-ref
         +--ro interface* [interface] fast-reroute {fast-reroute}?
         |     ...
         +--ro packet-counters
      |  +--ro level* [level] topologies* [name]
         |     ...
         +--ro interfaces
      |  +--ro interfaces* [interface] system-counters
         |     ...
         +--ro adjacencies
      |  +--ro adjacency* interfaces
         |     ...
         +--ro spf-log
         |  +--ro event* [id]
      |     ...

         +--ro lsp-log
         |  +--ro event* [id]
      |     ...
         +--ro database
         |  +--ro level-db* [level]
      |     ...
         +--ro hostnames
         +--ro hostname* [system-id]
               ...
rpcs:
   +---x clear-adjacency
   |  +--ro input
   |     +--ro routing-instance-name             rt:routing-instance-state-ref
   |     +--ro routing-protocol-instance-name    instance-state-ref
   |     +--ro level?                            level
   |     +--ro interface?                        string
   +---x clear-database
      +--ro input
         +--ro routing-instance-name             rt:routing-instance-state-ref
         +--ro routing-protocol-instance-name    instance-state-ref
         +--ro level?                            level
notifications:
   +---n database-overload
   |  +--ro instance-name?    string
   |  +--ro instance-level?   level
   |  +--ro overload?         enumeration
   +---n lsp-too-large
   |  +--ro instance-name?         string
   |  +--ro instance-level?        level
   |  +--ro interface-name?        string
   |  +--ro interface-level?       level
   |  +--ro extended-circuit-id?   extended-circuit-id
   |  +--ro pdu-size?              uint32
   |  +--ro lsp-id?                lsp-id
   +---n corrupted-lsp-detected
   |  +--ro instance-name?    string
   |  +--ro instance-level?   level
   |  +--ro lsp-id?           lsp-id
   +---n attempt-to-exceed-max-sequence
   |  +--ro instance-name?    string
   |  +--ro instance-level?   level
   |  +--ro lsp-id?           lsp-id
   +---n id-len-mismatch

2.1.  ISIS Configuration

   The ISIS configuration currently supports both VRF-centric and
   protocol-centric configuration.  This may be changed in future.

   In a protocol-centric configuration, the isis configuration is
   applied within the standard-routing-instance and the instance list
   helps to reference the routing-instance where ISIS is activated.

   In a VRF-centric configuration, the isis configuration is applied
   directly within the appropriate routing-instance where ISIS is
   activated.  In this case, the instance list will contain a single
   element.

   The ISIS configuration container is divided in:

   o  Global parameters.

   o  Per interface configuration (see Section 2.4).

   It would to up to extension modules to augment this model to support
   vendor specific parameters.

augment /rt:routing/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--rw isis
      +--rw instance* [routing-instance]
         +--rw routing-instance          rt:routing-instance-ref
         +--rw level-type?               level
         +--rw system-id?                system-id
         +--rw maximum-area-addresses?   uint8 {maximum-area-addresses}?
         +--rw area-address*             area-address
         +--rw mpls
         |  +--ro instance-name?         string  +--rw ipv4-router-id?   inet:ipv4-address {ipv4-router-id}?
         |  +--ro instance-level?        level  +--rw ipv6-router-id?   inet:ipv6-address {ipv6-router-id}?
         |  +--ro interface-name?        string  +--rw igp-ldp-sync {igp-ldp-sync}?
         +--rw reference-bandwidth?      uint32 {reference-bandwidth}?
         +--rw lsp-mtu?                  uint16
         +--rw lsp-lifetime?             uint16
         +--rw lsp-refresh?              uint16 {lsp-refresh}?
         +--rw graceful-restart {graceful-restart}?
         |  +--ro interface-level?       level  +--rw enabled?   boolean
         +--rw node-tag {node-tag}?
         |  +--ro extended-circuit-id?   extended-circuit-id  +--rw node-tag* [tag]
         |  +--ro pdu-field-len?         uint8     +--rw tag    uint32
         +--rw fast-reroute {fast-reroute}?
         |  +--ro raw-pdu?               binary
   +---n max-area-addresses-mismatch  +--rw lfa {lfa}?
         +--rw segment-routing {segment-routing}?
         |  +--ro instance-name?         string  +--rw enabled?    boolean
         |  +--ro instance-level?        level  +--rw bindings
         |  +--ro interface-name?        string     +--rw advertise?   boolean
         |  +--ro interface-level?       level     +--rw receive?     boolean
         +--rw authentication* [level]
         |  +--ro extended-circuit-id?   extended-circuit-id  +--rw (authentication-type)?
         |  +--ro max-area-addresses?    uint8  |  +--ro raw-pdu?               binary
   +---n own-lsp-purge  +--:(key-chain) {key-chain}?
         |  +--ro instance-name?         string  |  +--ro instance-level?        level  |  +--ro interface-name?        string  +--rw key-chain?      key-chain:key-chain-ref
         |  +--ro interface-level?       level  |  +--ro extended-circuit-id?   extended-circuit-id  +--:(password)
         |  +--ro lsp-id?                lsp-id
   +---n sequence-number-skipped  |  +--ro instance-name?     +--rw key?            string
         |  +--ro instance-level?        level
   |  +--ro interface-name?        string
   |  +--ro interface-level?       level
   |  +--ro extended-circuit-id?   extended-circuit-id
   |  +--ro lsp-id?                lsp-id
   +---n authentication-type-failure  |  +--ro instance-name?         string     +--rw (algorithm)?
         |  +--ro instance-level?        level  |  +--ro interface-name?        string        +--:(hmac-sha1-12)
         |  +--ro interface-level?       level  |  +--ro extended-circuit-id?   extended-circuit-id        |  +--ro raw-pdu?               binary
   +---n authentication-failure  +--rw hmac-sha1-12?   empty
         |  +--ro instance-name?         string  |  +--ro instance-level?        level        +--:(hmac-sha1-20)
         |  +--ro interface-name?        string  |  +--ro interface-level?       level        |  +--ro extended-circuit-id?   extended-circuit-id  +--rw hmac-sha1-20?   empty
         |  +--ro raw-pdu?               binary
   +---n version-skew  |  +--ro instance-name?         string        +--:(md5)
         |  +--ro instance-level?        level  |  +--ro interface-name?        string        |  +--ro interface-level?       level  +--rw md5?            empty
         |  +--ro extended-circuit-id?   extended-circuit-id  |  +--ro protocol-version?      uint8        +--:(sha-1)
         |  +--ro raw-pdu?               binary
   +---n area-mismatch  |  +--ro instance-name?         string        |  +--ro instance-level?        level  +--rw sha-1?          empty
         |  +--ro interface-name?        string  |  +--ro interface-level?       level        +--:(hmac-sha-1)
         |  +--ro extended-circuit-id?   extended-circuit-id  |  +--ro raw-pdu?               binary
   +---n rejected-adjacency        |  +--ro instance-name?         string  +--rw hmac-sha-1?     empty
         |  +--ro instance-level?        level  |  +--ro interface-name?        string        +--:(hmac-sha-256)
         |  +--ro interface-level?       level  |  +--ro extended-circuit-id?   extended-circuit-id        |  +--ro raw-pdu?               binary  +--rw hmac-sha-256?   empty
         |  +--ro reason?                string
   +---n protocols-supported-mismatch  |  +--ro instance-name?         string        +--:(hmac-sha-384)
         |  +--ro instance-level?        level  |  +--ro interface-name?        string        |  +--ro interface-level?       level  +--rw hmac-sha-384?   empty
         |  +--ro extended-circuit-id?   extended-circuit-id  |  +--ro raw-pdu?               binary        +--:(hmac-sha-512)
         |  +--ro protocols*             uint8
   +---n lsp-error-detected  |  +--ro instance-name?         string           +--rw hmac-sha-512?   empty
         |  +--ro instance-level?  +--rw level           level
         +--rw metric-type* [level]
         |  +--ro interface-name?        string  +--rw value?   enumeration
         |  +--ro interface-level?  +--rw level    level
         +--rw preference* [level]
         |  +--ro extended-circuit-id?   extended-circuit-id  +--rw (granularity)?
         |  +--ro lsp-id?                lsp-id  |  +--ro raw-pdu?               binary  +--:(detail)
         |  +--ro error-offset?          uint32  |  +--ro tlv-type?  |  +--rw internal?   uint8
   +---n adjacency-change
         |  +--ro instance-name?         string  |  +--ro instance-level?        level  |  +--ro interface-name?        string  +--rw external?   uint8
         |  +--ro interface-level?       level  |  +--ro extended-circuit-id?   extended-circuit-id  +--:(coarse)
         |  +--ro neighbor?              string  |  +--ro neighbor-system-id?    system-id     +--rw default?    uint8
         |  +--ro level?  +--rw level       level
         +--rw default-metric* [level]
         |  +--ro state?                 enumeration  +--rw value?   wide-metric
         |  +--ro reason?                string
   +---n lsp-received
   |  +--ro instance-name?         string
   |  +--ro instance-level?        level
   |  +--ro interface-name?        string
   |  +--ro interface-level?  +--rw level
   |  +--ro extended-circuit-id?   extended-circuit-id
   |  +--ro lsp-id?                lsp-id
   |  +--ro sequence?              uint32
   |  +--ro received-timestamp?    yang:timestamp
   |  +--ro neighbor-system-id?    system-id
   +---n lsp-generation
      +--ro instance-name?    string
      +--ro instance-level?    level
      +--ro lsp-id?           lsp-id
      +--ro sequence?         uint32
      +--ro send-timestamp?   yang:timestamp

2.1.  ISIS Configuration

   The ISIS configuration currently supports both VRF-centric and
   protocol-centric configuration.  This may be changed in future.  In a
   protocol-centric configuration, the isis configuration is applied
   within the standard-routing-instance and the instance list helps to
   reference the routing-instance where ISIS is activated.  In a VRF-
   centric configuration, the isis configuration is applied directly
   within the appropriate routing-instance where ISIS is activated.  In
   this case, the instance list will contain a single element.

   The ISIS configuration container is divided in:

   o  Global parameters.

   o  Per interface configuration (see Section 2.4).

   It would to up to extension modules to augment this model to support
   vendor specific parameters.

augment /rt:routing/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--rw isis
      +--rw instance* [routing-instance]
         +--rw routing-instance          rt:routing-instance-ref
         +--rw level-type?               level af* [af] {nlpid-control}?
         |  +--rw system-id?                system-id af         identityref
         |  +--rw maximum-area-addresses?   uint8 {maximum-area-addresses}? enabled?   boolean
         +--rw area-address*             area-address topologies* [name] {multi-topology}?
         |  +--rw mpls-te enabled?           boolean
         |  +--rw ipv4-router-id?   inet:ipv4-address {ipv4-router-id}? name               rt:rib-ref
         |  +--rw ipv6-router-id?   inet:ipv6-address {ipv6-router-id}? fast-reroute {fast-reroute}?
         |  |  +--rw reference-bandwidth?      uint32 {reference-bandwidth}? lfa {lfa}?
         |  +--rw lsp-mtu?                  uint16 segment-routing {segment-routing}?
         |  |  +--rw lsp-lifetime?             uint16 enabled?    boolean
         |  |  +--rw lsp-refresh?              uint16 {lsp-refresh}? bindings
         |  |     +--rw graceful-restart {graceful-restart}? advertise?   boolean
         |  |     +--rw enabled? receive?     boolean
         |  +--rw authentication* default-metric* [level]
         |  +--rw key?     string  |  +--rw type?    authentication-type value?   wide-metric
         |  |  +--rw level    level
         |  +--rw metric-type* [level] node-tag {node-tag}?
         |     +--rw value?   enumeration node-tag* [tag]
         |        +--rw level    level tag    uint32
         +--rw preference* overload* [level]
         |  +--rw (granularity)? status?    boolean
         |  |  +--:(detail)
         |  |  |  +--rw internal?   uint8
         |  |  |  +--rw external?   uint8
         |  |  +--:(coarse)
         |  |     +--rw default?    uint8
         |  +--rw level       level
         +--rw default-metric* [level]
         |  +--rw value?   wide-metric
         |  +--rw level    level
         +--rw af* [af] {nlpid-control}?
         |  +--rw af         string
         |  +--rw enabled?   boolean
         +--rw topologies* [name] {multi-topology}?
         |  +--rw enabled?          boolean
         |  +--rw name              rt:rib-ref
         |  +--rw default-metric* [level]
         |     +--rw value?   wide-metric
         |     +--rw level    level
         +--rw overload* [level]
         |  +--rw status?    boolean
         |  +--rw timeout?   uint16  +--rw timeout?   uint16
         |  +--rw level      level
         +--rw overload-max-metric* [level] {overload-max-metric}?
         |  +--rw status?    boolean
         |  +--rw timeout?   uint16
         |  +--rw level      level
         +--rw interfaces
            +--rw interface* [name]
                        ...

2.2.  Multitopology Parameters

   The topologies "topologies" list is used to enable support of MT extensions for
   specific address families.

   Each topology should refer to an existing RIB.

   Some specific parameters could be defined for a specific topology at
   global level and also at interface level.

2.3.  Per-Level Parameters

   Some parameters support per level configuration.  In this case, the
   parameter is built as a list, so different values could be used for
   each level.  The "level-all" permits to apply a value to both levels.

           +--rw priority* [level]
           |  +--rw value?   uint8
           |  +--rw level    level

   Example :

           <priority>
               <value>100</value>
                           <level>level-1</level>
           </priority>
                   <priority>
               <value>200</value>
                           <level>level-2</level>
           </priority>

2.4.  Per-Interface Parameters

   The per-interface section of the ISIS instance describes the
   interface specific parameters.

   The interface is referenced using a string.  It would be up to the
   server device reference to check if the an interface exists or not.  Using a
   string permits to support some specific implementations that use in the
   "interface all" stanza to apply a configuration to all interfaces. Interface YANG
   model.

   Each interface has interface-specific parameters that may have a
   different value per level as described in previous section.  An
   interface-specific parameter always override an ISIS global parameter
   .

   Some parameters like BFD and hello-padding are defined as containers
   to permit easy extension by vendor specific modules.

    +--rw interfaces
           +--rw interface* [name]
              +--rw name                       string                       if:interface-ref
              +--rw level-type?                level
              +--rw lsp-pacing-interval?       uint16
              +--rw lsp-retransmit-interval?   uint16
              +--rw passive?                   boolean
              +--rw csnp-interval?             uint16
              +--rw hello-padding
              |  +--rw enabled?   boolean
              +--rw mesh-group-enabled?        mesh-group-state
              +--rw mesh-group?                uint8
              +--rw interface-type?            interface-type
              +--rw enabled?                   boolean
              +--rw tag*                       uint32 {prefix-tag}?
              +--rw tag64*                     uint64 {prefix-tag64}?
              +--rw hello-authentication* [level]
              |  +--rw type?    authentication-type (authentication-type)?
              |  |  +--:(key-chain) {key-chain}?
              |  |  |  +--rw key-chain?      key-chain:key-chain-ref
              |  |  +--:(password)
              |  |     +--rw key?            string
              |  |     +--rw (algorithm)?
              |  |           ...
              |  +--rw level           level
              +--rw hello-interval* [level]
              |  +--rw value?   uint16
              |  +--rw level    level
              +--rw hello-multiplier* [level]
              |  +--rw value?   uint16
              |  +--rw level    level
              +--rw priority* [level]
              |  +--rw value?   uint8
              |  +--rw level    level
              +--rw metric* [level]
              |  +--rw value?   wide-metric
              |  +--rw level    level
              +--rw af* [af]
              |  +--rw af     string                 identityref
              |  +--rw segment-routing {segment-routing}?
              |  |  +--rw prefix-sid* [value]
              |  |     +--rw value-type?          enumeration
              |  |     +--rw value                uint32
              |  |     +--rw node-flag?           boolean
              |  |     +--rw last-hop-behavior?   enumeration
              |  +--rw bfd {bfd}?
              |        ...     +--rw enabled?   boolean
              +--rw topologies* [name]
              |  +--rw name               rt:rib-ref
              |  +--rw metric* [level]
              |  |  +--rw value?   wide-metric
              |  |  +--rw level    level
              |  +--rw fast-reroute {fast-reroute}?
              |  |  +--rw lfa* [level] {lfa}?
              |  |     +--rw candidate-disabled?   boolean
              |  |     +--rw enabled?              boolean
              |  |     +--rw remote-lfa {remote-lfa}?
              |  |     |     ...

2.5.  Operational State

   "isis" container provides operational states for ISIS.  This
   container is divided in multiple components:

   o  system-counters : provides statistical informations about the
      global system.

   o  interface-counters : provides statistical informations for each
      interface.

   o  packet-counters : provides statistical informations for each type
      of PDU.
              |  |     +--rw level                 level
              |  +--rw segment-routing {segment-routing}?
              |     +--rw authorize-bundle
              |     |  +--rw enabled?   boolean
              |     |  +--rw weight?    uint8
              |     +--rw advertise-protection?   enumeration
              +--rw fast-reroute {fast-reroute}?
              |  +--rw lfa* [level] {lfa}?
              |     +--rw candidate-disabled?   boolean
              |     +--rw enabled?              boolean
              |     +--rw remote-lfa {remote-lfa}?
              |     |  +--rw enabled?   boolean
              |     +--rw level                 level
              +--rw segment-routing {segment-routing}?
              |  +--rw authorize-bundle
              |  |  +--rw enabled?   boolean
              |  |  +--rw weight?    uint8
              |  +--rw advertise-protection?   enumeration
              +--rw mpls
                     +--rw igp-ldp-sync {igp-ldp-sync}?
                            +--rw enabled?   boolean

2.5.  ISO parameters

   Some ISO parameters may be required.

   This module augments interface configuration model to support ISO
   configuration parameters.

   The clns-mtu can be defined under the interface.

2.6.  IP FRR

   This YANG model supports LFA and remote LFA as IP FRR techniques.
   The "fast-reroute" container may be augmented by other models to
   support other IPFRR flavors (MRT ...).

   The current version of the model supports activation of LFA and
   remote LFA at interface only.  The global "lfa" container is present
   but kept empty to permit augmentation with vendor specific properties
   like policies.

   Remote LFA is considered as a child of LFA.  Remote LFA cannot be
   enabled if LFA is not enabled.

   The "candidate-disabled" permit to mark an interface to not be used
   as a backup.

2.7.  Segment Routing

   This item is still under discussion and some part of the proposed
   configuration may fit in a segment-routing specific model.

2.8.  Operational State

   "isis" container provides operational states for ISIS.  This
   container is divided in multiple components:

   o  system-counters : provides statistical informations about the
      global system.

   o  interface : provides configuration state information for each
      interface.

   o  adjacencies: provides state information about current ISIS
      adjacencies.

   o  spf-log: provides information about SPF events on the node.

   o  lsp-log: provides information about LSP events on the node
      (reception of an LSP or modification of local LSP).

   o  database: provides details on current LSDB.

   o  hostnames: provides information about system-id to hostname
      mappings.

   o  fast-reroute: provides information about IP FRR.

   o  segment-routing: provides information about segment-routing.

augment /rt:routing-state/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--ro isis
      +--ro system-counters
      | instance* [routing-instance]
         +--ro level* [level]
      | routing-instance    rt:routing-instance-ref
         +--ro level                            level-number fast-reroute {fast-reroute}?
         |  +--ro corrupted-lsps?                  uint32 protected-routes
         |  |  +--ro authentication-type-fails?       uint32 af-stats* [af prefix alternate]
         |  |     +--ro authentication-fails?            uint32 af                      identityref
         |  |     +--ro database-overload?               uint32 prefix                  string
         |  |     +--ro own-lsp-purge?                   uint32 alternate               string
         |  |     +--ro manual-address-drop-from-area?   uint32 alternate-type?         enumeration
         |  |     +--ro max-sequence?                    uint32 best?                   boolean
         |  |     +--ro sequence-number-skipped?         uint32 non-best-reason?        string
         |  |     +--ro id-len-mismatch?                 uint32 protection-available?   bits
         |  |     +--ro partition-changes? alternate-metric1?      uint32
         |  |     +--ro lsp-errors? alternate-metric2?      uint32
         |  |     +--ro spf-runs? alternate-metric3?      uint32
      +--ro interface-counters
         |  +--ro interface* [interface] nonprotected-routes
         |  |  +--ro interface af-stats* [af prefix]
         |  |     +--ro af        identityref
         |  |     +--ro prefix    string
         |  +--ro adjacency-changes?             uint32 protection-statistics* [frr-protection-method]
         |     +--ro adjacency-number?              uint32 frr-protection-method    string
         |     +--ro init-fails?                    uint32 af-stats* [af]
         |        +--ro adjacency-rejects?             uint32 af                      identityref
         |        +--ro id-len-mismatch? total-routes?           uint32
         |        +--ro max-area-addresses-mismatch? unprotected-routes?     uint32
         |        +--ro authentication-type-fails? protected-routes?       uint32
         |        +--ro authentication-fails? linkprotected-routes?   uint32
         |        +--ro lan-dis-changes? nodeprotected-routes?   uint32
         +--ro packet-counters topologies* [name]
         |  +--ro level* [level] name          rt:rib-ref
         |  +--ro level      level-number fast-route {fast-reroute}?
         |     +--ro iih protected-routes
         |     |  +--ro in?    uint32
      | af-stats* [af prefix alternate]
         |  +--ro out?   uint32     |     +--ro ish af                      identityref
         |     |     +--ro in?    uint32
      | prefix                  string
         |  +--ro out?   uint32     |     +--ro esh alternate               string
         |     |     +--ro in?    uint32 alternate-type?         enumeration
         |     |     +--ro out?   uint32 best?                   boolean
         |     |     +--ro lsp non-best-reason?        string
         |     |     +--ro in?    uint32 protection-available?   bits
         |     |     +--ro out? alternate-metric1?      uint32
         |     +--ro psnp
      |     |     +--ro in? alternate-metric2?      uint32
         |     |     +--ro out? alternate-metric3?      uint32
         |     +--ro csnp nonprotected-routes
         |     |  +--ro in?    uint32
      | af-stats* [af prefix]
         |  +--ro out?   uint32     |     +--ro unknown af        identityref
         |        +--ro in?    uint32     |     +--ro out?   uint32
      +--ro interfaces prefix    string
         |     +--ro interfaces* [interface] protection-statistics* [frr-protection-method]
         |        +--ro interface frr-protection-method    string
         |        +--ro circuit-id?            circuit-id af-stats* [af]
         |           +--ro admin-state?           admin-state af                      identityref
         |           +--ro oper-state?            oper-state total-routes?           uint32
         |           +--ro interface-type?        interface-type unprotected-routes?     uint32
         |           +--ro level?                 level protected-routes?       uint32
         |           +--ro passive?               empty linkprotected-routes?   uint32
         |           +--ro three-way-handshake?   empty
      +--ro adjacencies
      | nodeprotected-routes?   uint32
         +--ro adjacency* system-counters
         |  +--ro interface?                      string level* [level]
         |     +--ro level? level                            level-number
         |     +--ro neighbor-sysid?                 system-id
      |     +--ro neighbor-extended-circuit-id?   extended-circuit-id corrupted-lsps?                  uint32
         |     +--ro neighbor-snpa?                  snpa authentication-type-fails?       uint32
         |     +--ro neighbor-level?                 level authentication-fails?            uint32
         |     +--ro hold-timer?                     uint16 database-overload?               uint32
         |     +--ro neighbor-priority?              uint8 own-lsp-purge?                   uint32
         |     +--ro lastuptime?                     yang:timestamp manual-address-drop-from-area?   uint32
         |     +--ro state?                          enumeration
      +--ro spf-log max-sequence?                    uint32
         |     +--ro event* [id] sequence-number-skipped?         uint32
         |     +--ro id id-len-mismatch?                 uint32
         |     +--ro spf-type?             enumeration partition-changes?               uint32
         |     +--ro level?                level-number lsp-errors?                      uint32
         |     +--ro spf-delay? spf-runs?                        uint32
      |
         +--ro schedule-timestamp?   yang:timestamp interfaces
         |  +--ro start-timestamp?      yang:timestamp interfaces* [interface]
         |     +--ro end-timestamp?        yang:timestamp interface          string
         |     +--ro trigger-lsp* [lsp] status
         |        +--ro lsp         lsp-id     |  +--ro sequence?   uint32
      +--ro lsp-log circuit-id?            circuit-id
         |  +--ro event* [id]     |  +--ro id                    uint32 admin-state?           admin-state
         |     +--ro level?                level-number     |  +--ro lsp interface-type?        interface-type
         |     |  +--ro lsp?        lsp-id passive?               empty
         |     |  +--ro sequence?   uint32 three-way-handshake?   boolean
         |     |  +--ro received-timestamp?   yang:timestamp mesh-group-enabled?    mesh-group-state
         |     |  +--ro database mesh-group?            uint8
         |     |  +--ro level-db* level* [level]
         |     |     +--ro level                level-number
         |     +--ro lsp* [lsp-id]     |     +--ro lsp-id                           lsp-id priority?            uint8
         |     |     +--ro checksum? hello-multiplier?    uint16
         |     |     +--ro remaining-lifetime? hello-interval?      uint16
         |     |     +--ro sequence? dr-hello-interval?   uint32
         |     |     +--ro attributes?                      bits metric?              wide-metric
         |     +--ro is-neighbor fast-reroute {fast-reroute}?
         |     |  +--ro neighbor* [neighbor-id]
      | lfa* [level] {lfa}?
         |        ...     |     +--ro authentication candidate-disabled?   boolean
         |     |     +--ro authentication-type?   authentication-type enabled?              boolean
         |     |     +--ro authentication-key?    string remote-lfa {remote-lfa}?
         |     |     |  +--ro extended-is-neighbor enabled?   boolean
         |     |     +--ro neighbor* [neighbor-id] level                 level-number
         |     +--ro adjacencies
         |        ...     |  +--ro ipv4-internal-reachability adjacency*
         |     |     +--ro prefixes* [ip-prefix] neighbor-systype?               level
         |     |        ...     +--ro neighbor-sysid?                 system-id
         |     |     +--ro protocol-supported* neighbor-extended-circuit-id?   extended-circuit-id
         |     |     +--ro neighbor-snpa?                  snpa
         |     |     +--ro usage?                          level
         |     |     +--ro hold-timer?                     uint16
         |     |     +--ro neighbor-priority?              uint8
         |     |     +--ro ipv4-external-reachability lastuptime?                     yang:timestamp
         |     |     +--ro prefixes* [ip-prefix] state?                          enumeration
         |     |        ...     +--ro adjacency-sid* [value] {segment-routing}?
         |     |        +--ro ipv4-addresses*                  inet:ipv4-address af?                     identityref
         |     |        +--ro ipv4-te-routerid?                inet:ipv4-address value                   uint32
         |     |        +--ro extended-ipv4-reachability weight?                 uint8
         |     |        +--ro prefixes* [ip-prefix] protection-requested?   boolean
         |     +--ro topologies* [name]
         |        ...     |  +--ro dynamic-hostname?                string name            rt:rib-ref
         |     |  +--ro ipv6-te-routerid?                inet:ipv6-address fast-reroute {fast-reroute}?
         |     |  |  +--ro mt-is-neighbor lfa* [level] {lfa}?
         |     |  |     +--ro neighbor* [neighbor-id] candidate-disabled?   boolean
         |     |        ...  |     +--ro mt-entries enabled?              boolean
         |     |  |     +--ro topology* [MT-ID] remote-lfa {remote-lfa}?
         |     |  |     |     ...
         |     |  |     +--ro ipv6-addresses*                  inet:ipv6-address level                 level-number
         |     |  +--ro mt-extended-ipv4-reachability adjacencies
         |     |  |  +--ro prefixes* [ip-prefix] adjacency*
         |     |        ...  |     +--ro mt-ipv6-reachability neighbor-systype?               level
         |     |  |     +--ro prefixes* [ip-prefix] neighbor-sysid?                 system-id
         |     |        ...  |     +--ro ipv6-reachability neighbor-extended-circuit-id?   extended-circuit-id
         |     |  |     +--ro prefixes* [ip-prefix] neighbor-snpa?                  snpa
         |     |        ...  |     +--ro router-capabilities usage?                          level
         |     |  |     +--ro binary?   binary hold-timer?                     uint16
         |     |  |     +--ro hostnames neighbor-priority?              uint8
         |     |  |     +--ro hostname* [system-id] lastuptime?                     yang:timestamp
         |     |  |     +--ro system-id    system-id state?                          enumeration
         |     |  |     +--ro hostname?    string

3.  RPC Operations

   The "ietf-isis" module defines two RPC operations:

   o  clear-isis-database: reset the content of a particular ISIS
      database and restart database synchronization with the neighbors.

   o  clear-isis-adjacency: restart a particular set of ISIS
      adjacencies.

rpcs:
   +---x clear-adjacency adjacency-sid* [value] {segment-routing}?
         |     |  |           ...
         |     |  +--ro input level* [level]
         |     |     +--ro routing-instance-name             rt:routing-instance-state-ref level     level-number
         |     |     +--ro routing-protocol-instance-name    instance-state-ref metric?   wide-metric
         |     +--ro level?                            level event-counters
         |     |  +--ro interface?                        string
   +---x clear-database adjacency-changes?             uint32
         |     |  +--ro input adjacency-number?              uint32
         |     |  +--ro routing-instance-name             rt:routing-instance-state-ref init-fails?                    uint32
         |     |  +--ro routing-protocol-instance-name    instance-state-ref adjacency-rejects?             uint32
         |     |  +--ro level?                            level

4.  Notifications

   The id-len-mismatch?               uint32
         |     |  +--ro max-area-addresses-mismatch?   uint32
         |     |  +--ro authentication-type-fails?     uint32
         |     |  +--ro authentication-fails?          uint32
         |     |  +--ro lan-dis-changes?               uint32
         |     +--ro packet-counters
         |        +--ro level* [level]
         |           +--ro level      level-number
         |           +--ro iih
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro ish
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro esh
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro lsp
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro psnp
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro csnp
         |           |  +--ro in?    uint32
         |           |  +--ro out?   uint32
         |           +--ro unknown
         |              +--ro in?    uint32
         |              +--ro out?   uint32
         +--ro spf-log
         |  +--ro event* [id]
         |     +--ro id                    uint32
         |     +--ro spf-type?             enumeration
         |     +--ro level?                level-number
         |     +--ro spf-delay?            uint32
         |     +--ro schedule-timestamp?   yang:timestamp
         |     +--ro start-timestamp?      yang:timestamp
         |     +--ro end-timestamp?        yang:timestamp
         |     +--ro trigger-lsp* [lsp]
         |        +--ro lsp         lsp-id
         |        +--ro sequence?   uint32
         +--ro lsp-log
         |  +--ro event* [id]
         |     +--ro id                    uint32
         |     +--ro level?                level-number
         |     +--ro lsp
         |     |  +--ro lsp?        lsp-id
         |     |  +--ro sequence?   uint32
         |     +--ro received-timestamp?   yang:timestamp
         |     +--ro change?               bits
         +--ro database
         |  +--ro level-db* [level]
         |     +--ro level    level-number
         |     +--ro lsp* [lsp-id]
         |        +--ro lsp-id                           lsp-id
         |        +--ro checksum?                        uint16
         |        +--ro remaining-lifetime?              uint16
         |        +--ro sequence?                        uint32
         |        +--ro attributes?                      bits
         |        +--ro is-neighbor
         |        |  +--ro neighbor* [neighbor-id]
         |        |     +--ro neighbor-id       system-id
         |        |     +--ro i-e?              boolean
         |        |     +--ro default-metric?   std-metric
         |        |     +--ro delay-metric
         |        |     |     ...
         |        |     +--ro expense-metric
         |        |     |     ...

         |        |     +--ro error-metric
         |        |           ...
         |        +--ro authentication
         |        |  +--ro authentication-type?   string
         |        |  +--ro authentication-key?    string
         |        +--ro extended-is-neighbor
         |        |  +--ro neighbor* [neighbor-id]
         |        |     +--ro neighbor-id             system-id
         |        |     +--ro metric?                 wide-metric
         |        |     +--ro adjacency-segment-id* [value]
         |        |           ...
         |        +--ro ipv4-internal-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro up-down?          boolean
         |        |     +--ro i-e?              boolean
         |        |     +--ro ip-prefix         inet:ipv4-address
         |        |     +--ro prefix-len?       uint8
         |        |     +--ro default-metric?   std-metric
         |        |     +--ro delay-metric
         |        |     |     ...
         |        |     +--ro expense-metric
         |        |     |     ...
         |        |     +--ro error-metric
         |        |           ...
         |        +--ro protocol-supported*              uint8
         |        +--ro ipv4-external-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro up-down?          boolean
         |        |     +--ro i-e?              boolean
         |        |     +--ro ip-prefix         inet:ipv4-address
         |        |     +--ro prefix-len?       uint8
         |        |     +--ro default-metric?   std-metric
         |        |     +--ro delay-metric
         |        |     |     ...
         |        |     +--ro expense-metric
         |        |     |     ...
         |        |     +--ro error-metric
         |        |           ...
         |        +--ro ipv4-addresses*                  inet:ipv4-address
         |        +--ro ipv4-te-routerid?                inet:ipv4-address
         |        +--ro extended-ipv4-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro up-down?             boolean
         |        |     +--ro ip-prefix            inet:ipv4-address
         |        |     +--ro prefix-len?          uint8
         |        |     +--ro metric?              wide-metric
         |        |     +--ro tag*                 uint32
         |        |     +--ro tag64*               uint64
         |        |     +--ro prefix-segment-id* [value]
         |        |           ...
         |        +--ro dynamic-hostname?                string
         |        +--ro ipv6-te-routerid?                inet:ipv6-address
         |        +--ro mt-is-neighbor
         |        |  +--ro neighbor* [neighbor-id]
         |        |     +--ro MT-ID?                  uint16
         |        |     +--ro neighbor-id             system-id
         |        |     +--ro metric?                 wide-metric
         |        |     +--ro adjacency-segment-id* [value]
         |        |           ...
         |        +--ro mt-entries
         |        |  +--ro topology* [MT-ID]
         |        |     +--ro MT-ID         uint16
         |        |     +--ro attributes?   bits
         |        +--ro ipv6-addresses*                  inet:ipv6-address
         |        +--ro mt-extended-ipv4-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro MT-ID?               uint16
         |        |     +--ro up-down?             boolean
         |        |     +--ro ip-prefix            inet:ipv4-address
         |        |     +--ro prefix-len?          uint8
         |        |     +--ro metric?              wide-metric
         |        |     +--ro tag*                 uint32
         |        |     +--ro tag64*               uint64
         |        |     +--ro prefix-segment-id* [value]
         |        |           ...
         |        +--ro mt-ipv6-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro MT-ID?               uint16
         |        |     +--ro up-down?             boolean
         |        |     +--ro ip-prefix            inet:ipv6-address
         |        |     +--ro prefix-len?          uint8
         |        |     +--ro metric?              wide-metric
         |        |     +--ro tag*                 uint32
         |        |     +--ro tag64*               uint64
         |        |     +--ro prefix-segment-id* [value]
         |        |           ...
         |        +--ro ipv6-reachability
         |        |  +--ro prefixes* [ip-prefix]
         |        |     +--ro up-down?             boolean
         |        |     +--ro ip-prefix            inet:ipv6-address
         |        |     +--ro prefix-len?          uint8
         |        |     +--ro metric?              wide-metric
         |        |     +--ro tag*                 uint32
         |        |     +--ro tag64*               uint64
         |        |     +--ro prefix-segment-id* [value]
         |        |           ...

         |        +--ro segment-routing-bindings* [fec range] {segment-routing}?
         |        |  +--ro fec        string
         |        |  +--ro range      uint16
         |        |  +--ro flags?     bits
         |        |  +--ro weight?    uint8
         |        |  +--ro binding*
         |        |     +--ro prefix-sid
         |        |     |     ...
         |        |     +--ro ero-metric?                           uint32
         |        |     +--ro ero
         |        |     |     ...
         |        |     +--ro backup-ero
         |        |     |     ...
         |        |     +--ro unnumbered-interface-id-ero
         |        |     |     ...
         |        |     +--ro backup-unnumbered-interface-id-ero
         |        |           ...
         |        +--ro router-capabilities*
         |           +--ro flags?                       bits
         |           +--ro node-tag {node-tag}?
         |           |  +--ro node-tag*
         |           |        ...
         |           +--ro segment-routing*
         |           |  +--ro flags?            bits
         |           |  +--ro range?            uint32
         |           |  +--ro starting-value?   uint32
         |           +--ro segment-routing-algorithm*   uint8
         |           +--ro binary?                      binary
         +--ro hostnames
            +--ro hostname* [system-id]
               +--ro system-id    system-id
               +--ro hostname?    string

3.  RPC Operations

   The "ietf-isis" module defines two RPC operations:

   o  clear-isis-database: reset the content of a particular ISIS
      database and restart database synchronization with the neighbors.

   o  clear-isis-adjacency: restart a particular set of ISIS
      adjacencies.

rpcs:
   +---x clear-adjacency
   |  +--ro input
   |     +--ro routing-instance-name             rt:routing-instance-state-ref
   |     +--ro routing-protocol-instance-name    instance-state-ref
   |     +--ro level?                            level
   |     +--ro interface?                        string
   +---x clear-database
      +--ro input
         +--ro routing-instance-name             rt:routing-instance-state-ref
         +--ro routing-protocol-instance-name    instance-state-ref
         +--ro level?                            level

4.  Notifications

   The "ietf-isis" module introduces some notifications :

      database-overload : raised when overload condition is changed.

      lsp-too-large : raised when the system tries to propagate a too
      large PDU.

      corrupted-lsp-detected : raised when the system find that an LSP
      that was stored in memory has become corrupted.

      attempt-to-exceed-max-sequence : This notification is sent when
      the system wraps the 32-bit sequence counter of an LSP.

      id-len-mismatch : This notification is sent when we receive a PDU
      with a different value for the System ID length.

      max-area-addresses-mismatch : This notification is sent when we
      receive a PDU with a different value for the Maximum Area
      Addresses.

      own-lsp-purge : This notification is sent when the system receives
      a PDU with its own system ID and zero age.

      sequence-number-skipped : This notification is sent when the
      system receives a PDU with its own system ID and different
      contents.  The system has to reissue the LSP with a higher
      sequence number.

      authentication-type-failure : This notification is sent when the
      system receives a PDU with the wrong authentication type field.

      authentication-failure : This notification is sent when the system
      receives a PDU with the wrong authentication information.

      version-skew : This notification is sent when the system receives
      a PDU with a different protocol version number.

      area-mismatch : This notification is sent when the system receives
      a Hello PDU from an IS that does not share any area address.

      rejected-adjacency : This notification is sent when the system
      receives a Hello PDU from an IS but does not establish an
      adjacency for some reason.

      protocols-supported-mismatch : This notification is sent when the
      system receives a non pseudonode LSP that has no matching protocol
      supported.

      lsp-error-detected : This notification is sent when the system
      receives a LSP with a parse error.

      adjacency-change : This notification is sent when an ISIS
      adjacency moves to Up state or to Down state.

      lsp-received : This notification is sent when a LSP is received.

      lsp-generation : This notification is sent when a LSP is
      regenerated.

   notifications:
      +---n database-overload
      |  +--ro instance-name?    string
      |  +--ro instance-level?   level
      |  +--ro overload?         enumeration
      +---n lsp-too-large
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro pdu-size?              uint32
      |  +--ro lsp-id?                lsp-id
      +---n corrupted-lsp-detected
      |  +--ro instance-name?    string
      |  +--ro instance-level?   level
      |  +--ro lsp-id?           lsp-id
      +---n attempt-to-exceed-max-sequence
      |  +--ro instance-name?    string
      |  +--ro instance-level?   level
      |  +--ro lsp-id?           lsp-id
      +---n id-len-mismatch
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro pdu-field-len?         uint8
      |  +--ro raw-pdu?               binary
      +---n max-area-addresses-mismatch
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro max-area-addresses?    uint8
      |  +--ro raw-pdu?               binary
      +---n own-lsp-purge
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      +---n sequence-number-skipped
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      +---n authentication-type-failure
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      +---n authentication-failure
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      +---n version-skew
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro protocol-version?      uint8
      |  +--ro raw-pdu?               binary
      +---n area-mismatch
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      +---n rejected-adjacency
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      |  +--ro reason?                string
      +---n protocols-supported-mismatch
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      |  +--ro protocols*             uint8
      +---n lsp-error-detected
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      |  +--ro raw-pdu?               binary
      |  +--ro error-offset?          uint32
      |  +--ro tlv-type?              uint8
      +---n adjacency-change
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro neighbor?              string
      |  +--ro neighbor-system-id?    system-id
      |  +--ro level?                 level
      |  +--ro state?                 enumeration
      |  +--ro reason?                string
      +---n lsp-received
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      |  +--ro sequence?              uint32
      |  +--ro received-timestamp?    yang:timestamp
      |  +--ro neighbor-system-id?    system-id
      +---n lsp-generation
         +--ro instance-name?    string
         +--ro instance-level?   level
         +--ro interface-name? lsp-id?           lsp-id
         +--ro sequence?         uint32
         +--ro send-timestamp?   yang:timestamp

5.  Interaction with Other YANG Modules

   The "isis" configuration container augments the "/rt:routing/
   rt:routing-instance/rt:routing-protocols/routing-protocol" container
   of the ietf-routing module by defining ISIS specific parameters.

   The "isis" module augments "/if:interfaces/if:interface" with ISO
   specific parameters.

   The "isis" operational state container augments the "/rt:routing-
   state/rt:routing-instance/rt:routing-protocols/routing-protocol"
   container of the ietf-routing module by defining ISIS specific
   operational states.

   Some ISIS specific routes attributes are added to route objects of
   the ietf-routing module by augmenting "/rt:routing-
   state/rt:ribs/rt:rib/rt:routes/rt:route" and "/rt:active-
   route/rt:output/rt:route".

6.  YANG Module

   <CODE BEGINS> file "ietf-isis@2015-03-04.yang"

   module ietf-isis {
     namespace "urn:ietf:params:xml:ns:yang:ietf-isis";

     prefix isis;

     import ietf-routing {
               prefix "rt";
           }

     import ietf-inet-types {
       prefix inet;
     }

     import ietf-yang-types {
       prefix yang;
     }

     import ietf-interfaces {
       prefix "if";
     }

     organization
      "IETF ISIS Working Group";

     contact
       "WG List:  &lt;mailto:isis-wg@ietf.org&gt;

       Editor:    Stephane Litkowski
             &lt;mailto:stephane.litkowski@orange.com&gt;

           Derek Yeung
             &lt;mailto:myeung@cisco.com&gt;
           Acee Lindem
             &lt;mailto:acee@cisco.com&gt;
           Jeffrey Zhang
             &lt;mailto:zzhang@juniper.net&gt;
           Ladislav Lhotka
             &lt;mailto:llhotka@nic.cz&gt;
           Yi Yang
             &lt;mailto:yiya@cisco.com&gt;
           Dean Bogdanovic
             &lt;mailto:deanb@juniper.net&gt;
           Kiran Agrahara Sreenivasa
             &lt;mailto:kkoushik@brocade.com&gt;
           Yingzhen Qu
             &lt;mailto:yiqu@cisco.com&gt;

       ";

     description
       "The YANG module defines a generic configuration model for
       ISIS common across all of the vendor implementations.";

     revision 2015-03-03 {
       description
         "
           * Defining hierarchy for operational states
           * Adding CLNS MTU

         ";
       reference "draft-ietf-isis-yang-isis-02";
     }
     revision 2015-02-20 {
       description
         "
           * Removing igp-ldp-sync timer in IS-IS

         ";
       reference "";
     }
     revision 2014-12-15 {
       description
         "
           * Adding IPFRR
           * Adding igp-ldp sync
           * Adding segment routing
           * Adding instance reference to operational states.
           * Move AF type from string to identity
           * Updated router-capability in LSDB description.
           * packet counters moved to interface-packet-counters.
           * Added modification information in lsp-log
         ";
       reference "";
     }
     revision 2014-10-24 {
       description
         "
           * Change hello-padding to container
           * Change bfd to container
           * Make BFD a feature
           * Creates mpls-te container and put router-id
           inside
           * Remove GR helper disable and timers
         ";
       reference "draft-ietf-isis-yang-isis-cfg-01";
     }
     revision 2014-10-21 {
       description
         "
          * Interface metric move from af container to interface
           container
          * Hello-padding on interface moved to hello-padding-disable
          with empty type
          * three-way-handshake removed
          * route preference changed to a choice
          * csnp-authentication/psnp-authentication merged
          to authentication container
          * lsp-gen-interval-exp-delay removed
          * Added overload-max-metric feature
          * overload-max-metric is in a separate container
         ";
       reference "";
     }

     revision 2014-10-07 {
       description
         "
         * Removed spf parameters (should be part of
           vendor specific extensions.
         * Removed hello parameters at global level.
         * Interface configuration uses a string
      |  +--ro interface-level? rather
         than a reference. This permits to map to some
         vendor specific configuration.
         ";
       reference "draft-ietf-isis-yang-isis-00";
     }
     revision 2014-09-26 {
       description
         "
         * Add BFD support
         * remove max-elements to max-area-addresses
         ";
       reference "";
     }
     revision 2014-09-11 {
       description
         "
         * Add level
      |  +--ro extended-circuit-id? parameter to ispf and spf delay
         * Add LSP generation as a feature
         * Make lsp-refresh a feature
         * Change parameter container to list
         ";
       reference "";
     }
     revision 2014-09-05 {
       description
       " Rewrite of the global hierarchy.";
       reference "";
     }
     revision 2014-08-06 {
       description
       "
       * isis-state renamed to isis.
       * Add GR support
       * Add meshgroup support
       * Add CLNS support
       * Add 64bits tags
       * Add notifications to be aligned with MIB4444
       * Add packet-counters, interface-counters, system-counters
         states
       * Add 3-way handshake support
       * Rename isis-adjacency-updown to adjacency-change
       * Add notification for LSP reception
       * Use feature for reference BW
       * Add lsp-retransmit-interval on interfaces
       * Rename lsp-interval to lsp-pacing-interval
       * Add ispf support as feature
       * Add spf delay support as feature (2step & exp backoff)
       * Add maximum-area-addresses
       * Add default-metric
       ";
       reference "RFC XXXX: YANG Data Model for ISIS Protocol";
     }
     revision 2014-06-25 {
       description "
       * isis-cfg renamed to isis.
       * Add precisions on authentication-keys in description
       ";
       reference "draft-litkowski-isis-yang-isis-01";
     }

     revision 2014-06-20 {
       description "
       * isis-op renamed to isis-state.
       * Multiple instances under ISIS are removed.
       * interface-cfg grouping removed and content
         is directly included in container isis.
       * TLVxx renamed with human-readable name in isis-database.
         TLV reference are putted in description.
       * Reference to core routing module were fixed.
       * Namespace fixed.
       * Add simple-iso-address type.
       * area-id and system-id in ISIS container are merged to
         nsap-address.
       * Add isis-system-id type.
       * Add isis-lsp-id type.
       * Add remaining-lifetime leaf in isis-database.
       * Add TLV2 (is-neighbor) in isis-database.
       * Renamed some container name for consistency
         reason ('isis-' prefixed).
       * Add new identities isis-cfg and isis-state.
       * Add descriptions.
       * Add notification isis-adjacency-updown.

       * Add RPC clear-isis-adjacency and clear-isis-database.
       ";
       reference "draft-litkowski-isis-yang-isis-00";
     }

     revision 2014-06-11 {
       description "Initial revision.";
       reference "draft-litkowski-netmod-isis-cfg-00";
     }
     identity isis {
       base rt:routing-protocol;
       description "Identity for the ISIS routing protocol.";
     }

     identity isis-adjacency-change {
       description "Identity for the ISIS routing protocol
         adjacency state.";
     }

     identity clear-isis-database {
       description "Identity for the ISIS routing protocol
         database reset action.";
     }

     identity clear-isis-adjacency {
       description "Identity for the ISIS routing protocol
         adjacency reset action.";
     }

     /* Feature definitions */

     feature segment-routing {
       description
        "Support of segment-routing.";
     }
     feature node-tag {
       description
         "Support of node tag.";
     }
     feature igp-ldp-sync {
       description
         "Support of RFC5443.";
     }
     feature fast-reroute {
       description
         "Support of IPFRR.";
     }
     feature  lfa {
       description
         "Support of Loop Free Alternates.";
     }
     feature remote-lfa {
       description
         "Support of remote Loop Free Alternates.";
     }

     feature bfd {
       description
         "Support of BFD.";
     }
     feature overload-max-metric {
       description
         "Support of overload by setting
          all links to max metric.";
     }
     feature prefix-tag {
       description
         "Add 32bit tag to prefixes";
     }
     feature prefix-tag64 {
       description
         "Add 64bit tag to prefixes";
     }
     feature reference-bandwidth {
       description
         "Use a reference bandwidth to compute metric.";
     }
     feature ipv4-router-id {
       description
        "Support of IPv4 router ID configuration under ISIS.";
     }

     feature ipv6-router-id {
       description
        "Support of IPv6 router ID configuration under ISIS.";
     }

     feature multi-topology {
       description
        "Multitopology routing support.";
     }
     feature nlpid-control {
       description
        "This feature controls the advertisement
         of support NLPID within ISIS configuration.";

     }
     feature graceful-restart {
       description
         "Graceful restart support as per RFC5306.";
     }

     feature lsp-refresh {
       description
         "Configuration of LSP refresh interval.";
     }

     feature maximum-area-addresses {
       description
         "Support of maximum-area-addresses config.";
     }

     /* Type definitions */

     typedef instance-state-ref {
       type leafref {
         path "/rt:routing-state/rt:routing-instance/"
         +"rt:routing-protocols/rt:routing-protocol/rt:name";
       }
       description
          "This type is used for leaves that reference state data of
           an ISIS protocol instance.";
     }

     typedef admin-state {
       type enumeration {
         enum "up" {
           description
            "Up state";
         }
         enum "down" {
           description
            "Down state";
         }
       }
       description
        "Administrative state of a component.";
     }
     typedef oper-state {
       type enumeration {
         enum "up" {
           description
            "Up state";
         }
         enum "down" {
           description
            "Down state";
         }
       }
       description
        "Operational state of a component.";
     }
     typedef circuit-id {
       type uint8;
       description
        "This type defines the circuit ID
        associated with an interface.";
     }

     typedef extended-circuit-id
      |  +--ro raw-pdu?               binary
      |  +--ro reason?                string
      +---n protocols-supported-mismatch
      |  +--ro instance-name?         string
      |  +--ro instance-level? {
       type uint32;
       description
        "This type defines the extended circuit ID
        associated with an interface.";
     }

     typedef interface-type {
       type enumeration {
         enum broadcast {
           description "Broadcast interface type.
           Would result in DIS election.";
         }
         enum point-to-point {
           description
            "Point to point interface type.";
         }
       }
       description
        "This type defines the type of adjacency
        to be established on the interface.
        This is affecting the type of hello
        message that would be used.";

     }
     typedef authentication-type {
       type enumeration {
           enum  none {
             description "No authentication used.";
           }
           enum  plaintext {
             description "Plain text password used.";
           }
           enum  message-digest {
             description "MD5 digest used.";
           }
       }
       description
       "This type defines available authentication types.";
     }

     typedef level
      |  +--ro interface-name?        string
      |  +--ro interface-level? {
       type enumeration {
         enum "level-1" {
           description
            "This enum describes L1 only capability.";
         }
         enum "level-2" {
           description
            "This enum describes L2 only capability.";
         }
         enum "level-all" {
           description
            "This enum describes both levels capability.";
         }
       }
       default "level-all";
       description
        "This type defines ISIS level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro raw-pdu?               binary
      |  +--ro protocols* of an object.";

     }

     typedef level-number {
       type uint8
      +---n lsp-error-detected
      |  +--ro instance-name? {
         range "1 .. 2";
       }
       description
        "This type defines a current ISIS level.";
     }

     typedef lsp-id {
       type string {
         pattern
          '[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]'
                +'{4}\.[0-9][0-9]-[0-9][0-9]';
       }
       description
        "This type defines ISIS LSP ID using pattern,
         system id looks like : 0143.0438.AeF0.02-01";
     }

     typedef area-address {
       type string
      |  +--ro instance-level?        level
      |  +--ro interface-name? {
         pattern '[0-9A-Fa-f]{2}\.([0-9A-Fa-f]{4}\.){0,3}';
       }
       description
        "This type defines the area address.";
     }

     typedef snpa {
       type string
      |  +--ro interface-level?       level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      |  +--ro raw-pdu?               binary
      |  +--ro error-offset? {
         length "0 .. 20";
       }
       description
        "This type defines Subnetwork Point of Attachement format.";

     }

     typedef system-id {
       type string {
         pattern
          '[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.00';
       }
       description
        "This type defines ISIS system id using pattern,
         system id looks like : 0143.0438.AeF0.00";
     }

     typedef wide-metric {
       type uint32
      |  +--ro tlv-type? {
         range "0 .. 16777215";
       }
       description
        "This type defines wide style format
         of ISIS metric.";
     }

     typedef std-metric {
       type uint8
      +---n adjacency-change
      |  +--ro instance-name?         string
      |  +--ro instance-level? {
         range "0 .. 63";
       }
       description
        "This type defines old style format
         of ISIS metric.";
     }
     typedef mesh-group-state {
       type enumeration {
         enum "meshInactive" {
           description
            "Interface is not part of a mesh group.";
         }
         enum "meshSet" {
           description
            "Interface is part of a mesh group.";
         }
         enum "meshBlocked" {
           description
            "LSPs must not be flooded over that interface.";
         }
       }
       description
        "This type describes meshgroup state of an interface";
     }

     /* Grouping definitions */

     grouping notification-instance-hdr {
       description
        "This group describes common instance specific
         data for notifications.";
       leaf instance-name {
         type string;
         description
          "Describes the name of the ISIS instance.";
       }
       leaf instance-level {
         type level;
         description
          "Describes the ISIS level
      |  +--ro interface-name?        string
      |  +--ro interface-level? of the instance.";
       }
     }

     grouping notification-interface-hdr {
       description
        "This group describes common interface specific
         data for notifications.";
       leaf interface-name {
         type string;
         description
          "Describes the name of the ISIS interface.";
       }
       leaf interface-level {
         type level;
         description
          "Describes the ISIS level
      |  +--ro extended-circuit-id? of the interface.";
       }
       leaf extended-circuit-id
      |  +--ro neighbor?              string
      |  +--ro neighbor-system-id?    system-id
      |  +--ro level?                 level
      |  +--ro state? {
         type extended-circuit-id;
         description
          "Describes the extended circuit-id of the interface.";
       }
     }

     grouping route-content {
       description
        "This group add isis-specific route properties.";
       leaf metric {
         type uint32;
         description
          "This leaf describes ISIS metric of a route.";
       }
       leaf-list tag {
         type uint64;
         description
          "This leaf describes list of tags associated
           with the route. The leaf describes both
           32bits and 64bits tags.";
       }
       leaf route-type {
         type enumeration
      |  +--ro reason?                string
      +---n lsp-received
      |  +--ro instance-name?         string
      |  +--ro instance-level?        level
      |  +--ro interface-name?        string
      |  +--ro interface-level? {
           enum l2-up-internal {
             description "Level 2 internal route
              and not leaked to a lower level";
           }
           enum l1-up-internal {
             description "Level 1 internal route
              and not leaked to a lower level";
           }
           enum l2-up-external {
             description "Level 2 external route
              and not leaked to a lower level";
           }
           enum l1-up-external {
             description "Level 1 external route
              and not leaked to a lower level";
           }
           enum l2-down-internal {
             description "Level 2 internal route
              and leaked to a lower level";

           }
           enum l1-down-internal {
             description "Level 1 internal route
              and leaked to a lower level";
           }
           enum l2-down-external {
             description "Level 2 external route
              and leaked to a lower level";
           }
           enum l1-down-external {
             description "Level 1 external route
              and leaked to a lower level";
           }
         }
         description
          "This leaf describes the type of ISIS route.";
       }
       leaf segment-id {
         if-feature segment-routing;
         type uint32;
         description
          "Segment ID or MPLS label value
          used to reach the prefix.";
       }
     }

     grouping fast-reroute-global-cfg {
       description
        "This group defines global
        configuration of IPFRR.";
       container fast-reroute {
         if-feature fast-reroute;
         description
           "This container may be
           augmented with global parameters
           for IPFRR.";
           container lfa {
             if-feature lfa;
             description
               "This container may be
               augmented with global parameters
               for LFA.
               Creating the container has no effect on
               LFA activation.";
           }
       }
     }
     grouping fast-reroute-if-cfg {
       description
        "This group defines interface
        configuration of IPFRR.";
       container fast-reroute {
         if-feature fast-reroute;

         list lfa {
           if-feature lfa;

           key level;

           leaf candidate-disabled {
             type boolean;
             description
              "Prevent the interface to be used as backup.";
           }
           leaf enabled {
             type boolean;
             description
              "Activates LFA.
              This model assumes activation
              of per-prefix LFA.";
           }

           container remote-lfa {
             if-feature remote-lfa;
             leaf enabled {
               type boolean;
               description
               "Activates rLFA.";
             }
             description
              "remote LFA configuration.";
           }
           leaf level
      |  +--ro extended-circuit-id?   extended-circuit-id
      |  +--ro lsp-id?                lsp-id
      |  +--ro sequence?              uint32
      |  +--ro received-timestamp?    yang:timestamp
      |  +--ro neighbor-system-id?    system-id
      +---n lsp-generation
         +--ro instance-name?    string
         +--ro instance-level? {
             type level;
             description
               "Level applicability.";
           }
           description
            "LFA configuration.";
         }
         description
          "Fast-reroute configuration.";
       }
     }
     grouping segment-routing-global-cfg {
       description
        "This grouping defines SR global config";
       container segment-routing {
         if-feature segment-routing;
         leaf enabled {
           type boolean;
           default false;
           description
            "Enables segment-routing
            protocol extensions.";
         }
         container bindings {
           leaf advertise {
             type boolean;
             default true;
             description
             "Authorize the advertise
             of local mappings in binding TLV.";
           }
           leaf receive {
             type boolean;
             default true;
             description
             "Authorize the reception and usage
             of binding TLV.";
           }
           description
            "Control of binding advertisement
            and reception.";
         }

         description
         "segment routing global config.";
       }
     }

     grouping segment-routing-if-cfg {
       description
        "This grouping defines SR interface config";
       container segment-routing {
         if-feature segment-routing;
         container authorize-bundle {
           leaf enabled {
             type boolean;
             description
              "Enable/disable S flag.";
           }
           leaf weight {
             type uint8;
             description
              "The value represents the
              weight of the Adj-SID
             for the purpose of load balancing.";
           }
           description
            "Control advertisement of S flag.
            Enable to advertise a common Adj-SID
            for parallel links.";
         }
         leaf advertise-protection {
           type enumeration {
             enum "single" {
               description
                "A single Adj-SID is associated
                with the adjacency and reflects
                the protection configuration.";
             }
             enum "dual" {
               description
                "Two Adj-SIDs will be associated
                with the adjacency if interface
                is protected. In this case
                one will be enforced with
                backup flag set, the other
                will be enforced to backup flag unset.
                In case, protection is not configured,
                a single Adj-SID will be advertised
                with backup flag unset.";
             }
           }
           description
            "If set, the Adj-SID refers to an
           adjacency being protected.";
         }
         description
          "Configuration of segment-routing
           adjacency SID properties.";
       }
     }

     grouping prefix-segment-id {
       description
        "This group defines segment routing extensions
        for prefixes.";
         leaf flags {
           type bits {
             bit readvertisment {
               position 7;
               description
                "If set, then the prefix to
               which this Prefix-SID is attached,
               has been propagated by the
               router either from another level
         +--ro lsp-id?           lsp-id
         +--ro sequence?         uint32
         +--ro send-timestamp?   yang:timestamp

5.  Interaction
               or from redistribution.";
             }
             bit node {
               position 6;
               description
                "If set, then the Prefix-SID refers to
                 the router identified by the prefix.";
             }
             bit php {
               position 5;
               description
               "If set, then the penultimate hop MUST NOT
               pop the Prefix-SID before delivering the packet
               to the node
               that advertised the Prefix-SID.";
             }
             bit explicit-null {
               position 4;
               description
               "If set, any upstream neighbor of
               the Prefix-SID originator MUST replace
               the Prefix-SID with a
               Prefix-SID having an
               Explicit-NULL value (0 for IPv4 and 2 for
               IPv6) before forwarding the packet.";
             }
             bit  value {
               position 3;
               description
               "If set, then the Prefix-SID carries a
               value (instead of an index).
               By default the flag is UNSET.";

             }
             bit  local {
               position 2;
               description
               "If set, then the value/index carried by
               the Prefix-SID has local significance.
               By default the flag is UNSET.";
             }
           }
           description
            "Describes flags associated with the
            segment ID.";
         }

         leaf algorithm {
           type uint8;
           description
            "Algorithm to be used for path computation.";
         }
         leaf value {
           type uint32;
           description
            "Value of the prefix-SID.";
         }

     }

     grouping adjacency-segment-id {
       description
        "This group defines segment routing extensions
        for adjacencies.";

         leaf flags {
           type bits {
             bit address-family {
               position 7;
               description
                "If unset, then the Adj-SID refers
               to an adjacency with Other YANG Modules

   The "isis" configuration container augments outgoing IPv4 encapsulation.
               If set then the "/rt:routing/
   rt:routing-instance/rt:routing-protocols/routing-protocol" container
   of Adj-SID refers to an adjacency
               with outgoing IPv6 encapsulation.";
             }
             bit backup {
               position 6;
               description
                "If set, the ietf-routing module by defining ISIS specific parameters.

   The "isis" operational state container augments Adj-SID refers to an
               adjacency being protected
               (e.g.: using IPFRR or MPLS-FRR)";
             }
             bit  value {
               position 5;
               description
               "If set, then the "/rt:routing-
   state/rt:routing-instance/rt:routing-protocols/routing-protocol"
   container SID carries a
               value (instead of an index).
               By default the ietf-routing module flag is SET.";

             }
             bit  local {
               position 4;
               description
               "If set, then the value/index carried by defining ISIS specific
   operational states.

   Some ISIS specific routes attributes are added
               the SID has local significance.
               By default the flag is SET.";
             }
             bit  set {
               position 3;
               description
               "When set, the S-Flag indicates that the
               Adj-SID refers to route objects a set of adjacencies";
             }
           }

           description
            "Describes flags associated with the ietf-routing module by augmenting "/rt:routing-
   state/rt:ribs/rt:rib/rt:routes/rt:route" and "/rt:active-
   route/rt:output/rt:route".

6.  YANG Module

<CODE BEGINS> file "ietf-isis@2014-10-24.yang"

module ietf-isis {
    namespace "urn:ietf:params:xml:ns:yang:ietf-isis";

    prefix isis;

    import ietf-routing {
            prefix "rt";
            segment ID.";
         }

    import ietf-inet-types
         leaf weight {
        prefix inet;
           type uint8;
           description
            "The value represents the weight of the Adj-SID
             for the purpose of load balancing.";
         }
    import ietf-yang-types
         leaf neighbor-id {
        prefix yang;
    }

    organization
     "IETF ISIS Working Group";

    contact
        "WG List:   &lt;mailto:isis-wg@ietf.org&gt;

        Editor:     Stephane Litkowski
                    &lt;mailto:stephane.litkowski@orange.com&gt;

                Derek Yeung
                    &lt;mailto:myeung@cisco.com&gt;
                Acee Lindem
                    &lt;mailto:acee@cisco.com&gt;
                Jeffrey Zhang
                    &lt;mailto:zzhang@juniper.net&gt;
                Ladislav Lhotka
                    &lt;mailto:llhotka@nic.cz&gt;
                Yi Yang
                    &lt;mailto:yiya@cisco.com&gt;
                Dean Bogdanovic
                    &lt;mailto:deanb@juniper.net&gt;
                Kiran Agrahara Sreenivasa
                    &lt;mailto:kkoushik@brocade.com&gt;
                Yingzhen Qu
                    &lt;mailto:yiqu@cisco.com&gt;

        ";
           type system-id;
           description
            "Describes the system ID of the neighbor
            associated with the SID value. This is only
            used on LAN adjacencies.";
         }
         leaf value {
           type uint32;
           description
        "The YANG module
            "Value of the Adj-SID.";
         }

     }

     grouping prefix-ipv4-std {
       description
        "This group defines a generic configuration model for
        ISIS common across all attributes of an
         IPv4 standard prefix.";
       leaf up-down {
         type boolean;
         description
          "This leaf expresses the vendor implementations.";

    revision 2014-10-24 value of up/down bit.";
       }
       leaf i-e {
         type boolean;
         description
            "
                * Change hello-padding to container
                * Change bfd to container
                * Make BFD a feature
                * Creates mpls-te container and put router-id
                inside
                * Remove GR helper disable and timers
            ";
        reference "draft-ietf-isis-yang-isis-cfg-01";
          "This leaf expresses the value of I/E bit.";
       }
    revision 2014-10-21
       leaf ip-prefix {
         type inet:ipv4-address;
         description
            "
             * Interface metric move from af container to interface
              container
             * Hello-padding on interface moved to hello-padding-disable
             with empty
          "This leaf describes the IPv4 prefix";
       }
       leaf prefix-len {
         type
             * three-way-handshake removed
             * route preference changed to a choice
             * csnp-authentication/psnp-authentication merged
             to authentication container
             * lsp-gen-interval-exp-delay removed
             * Added overload-max-metric feature
             * overload-max-metric is uint8;
         description
          "This leaf describes the IPv4 prefix len in a separate container
            ";
        reference ""; bits";
       }

    revision 2014-10-07
       leaf default-metric {
         type std-metric;
         description
            "
            * Removed spf parameters (should be part of
              vendor specific extensions.
            * Removed hello parameters at global level.
            * Interface configuration uses a string rather
            than a reference. This permits to map to some
            vendor specific configuration.
            ";
        reference "draft-ietf-isis-yang-isis-00";
          "This leaf describes the ISIS default metric value";
       }
       container delay-metric {
         leaf metric {
           type std-metric;
           description
            "This leaf describes the ISIS delay metric value";
         }
    revision 2014-09-26
         leaf supported {
           type boolean;
           default "false";
           description
            "
            * Add BFD support
            * remove max-elements to max-area-addresses
            ";
        reference "";
            "This leaf describes if the metric is supported.";
         }
    revision 2014-09-11 {

         description
            "
            * Add level parameter to ispf and spf
          "This container defines the ISIS delay
            * Add LSP generation as a feature
            * Make lsp-refresh a feature
            * Change parameter metric.";
       }
       container to list
            ";
        reference ""; expense-metric {
         leaf metric {
           type std-metric;
           description
            "This leaf describes the ISIS expense metric value";
         }
    revision 2014-09-05
         leaf supported {
           type boolean;
           default "false";
           description
        " Rewrite of
            "This leaf describes if the global hierarchy.";
        reference ""; metric is supported.";
         }
    revision 2014-08-06
         description
          "This container defines the ISIS expense metric.";
       }
       container error-metric {
         leaf metric {
           type std-metric;
           description
        "
        * isis-state renamed to isis.
        * Add GR support
        * Add meshgroup support
        * Add CLNS support
        * Add 64bits tags
        * Add notifications to be aligned with MIB4444
        * Add packet-counters, interface-counters, system-counters
          states
        * Add 3-way handshake support
        * Rename isis-adjacency-updown to adjacency-change
        * Add notification for LSP reception
        * Use feature for reference BW
        * Add lsp-retransmit-interval on interfaces
        * Rename lsp-interval to lsp-pacing-interval
        * Add ispf support as feature
        * Add spf delay support as feature (2step & exp backoff)
        * Add maximum-area-addresses
        * Add default-metric
        ";
        reference "RFC XXXX: YANG Data Model for
            "This leaf describes the ISIS error metric value";
         }
         leaf supported {
           type boolean;
           default "false";
           description
            "This leaf describes if the metric is supported.";
         }

         description
          "This container defines the ISIS Protocol"; error metric.";
       }
    revision 2014-06-25
     }

     grouping prefix-ipv4-extended {
       description "
        * isis-cfg renamed to isis.
        * Add precisions on authentication-keys in
        "This group defines attributes of an
         IPv4 extended prefix.";
       leaf up-down {
         type boolean;
         description
        ";
        reference "draft-litkowski-isis-yang-isis-01";
          "This leaf expresses the value of up/down bit.";
       }

    revision 2014-06-20
       leaf ip-prefix {
         type inet:ipv4-address;
         description "
        * isis-op renamed to isis-state.
        * Multiple instances under ISIS are removed.
        * interface-cfg grouping removed and content
          is directly included in container isis.
        * TLVxx renamed with human-readable name in isis-database.
          TLV reference are putted in description.
        * Reference to core routing module were fixed.
        * Namespace fixed.
        * Add simple-iso-address type.

        * area-id and system-id
          "This leaf describes the IPv4 prefix";
       }
       leaf prefix-len {
         type uint8;
         description
          "This leaf describes the IPv4 prefix len in bits";
       }

       leaf metric {
         type wide-metric;
         description
          "This leaf describes the ISIS container are merged to
          nsap-address.
        * Add isis-system-id type.
        * Add isis-lsp-id type.
        * Add remaining-lifetime metric value";
       }
       leaf-list tag {
         type uint32;
         description
          "This leaf in isis-database.
        * Add TLV2 (is-neighbor) in isis-database.
        * Renamed some container name for consistency
          reason ('isis-' prefixed).
        * Add new identities isis-cfg and isis-state.
        * Add descriptions.
        * Add notification isis-adjacency-updown.
        * Add RPC clear-isis-adjacency and clear-isis-database.
        ";
        reference "draft-litkowski-isis-yang-isis-00"; describes a list of tags associated with
          the prefix.";
       }

    revision 2014-06-11
       leaf-list tag64 {
         type uint64;
         description
          "This leaf describes a list of 64-bit tags associated with
          the prefix.";
       }
       list prefix-segment-id {
         key value;
         uses prefix-segment-id;
         description
          "List of prefix-segment-id.";
       }
     }

     grouping prefix-ipv6-extended {
       description
        "This group defines attributes of an
         IPv6 prefix.";
       leaf up-down {
         type boolean;
         description "Initial revision.";
        reference "draft-litkowski-netmod-isis-cfg-00";
          "This leaf expresses the value of up/down bit.";
       }
    identity isis
       leaf ip-prefix {
        base rt:routing-protocol;
         type inet:ipv6-address;
         description "Identity for
          "This leaf describes the ISIS routing protocol."; IPv6 prefix";
       }

    identity isis-adjacency-change
       leaf prefix-len {
         type uint8;
         description "Identity for
          "This leaf describes the ISIS routing protocol
          adjacency state."; IPv4 prefix len in bits";
       }

    identity clear-isis-database

       leaf metric {
         type wide-metric;
         description "Identity for
          "This leaf describes the ISIS routing protocol
          database reset action."; metric value";

       }

    identity clear-isis-adjacency
       leaf-list tag {
         type uint32;
         description "Identity for
          "This leaf describes a list of tags associated with
          the ISIS routing protocol
          adjacency reset action."; prefix.";
       }

    feature bfd
       leaf-list tag64 {
         type uint64;
         description
            "Support
          "This leaf describes a list of BFD."; 64-bit tags associated with
          the prefix.";
       }
    feature overload-max-metric
       list prefix-segment-id {
         key value;
         uses prefix-segment-id;
         description
            "Support
          "List of overload by setting
             all links to max metric."; prefix-segment-id.";
       }
    feature prefix-tag
     }

     grouping neighbor-extended {
       description
            "Add 32bit tag to prefixes";
        "This group defines attributes of an
         ISIS extended neighbor.";
       leaf neighbor-id {
         type system-id;
         description
          "This leaf describes the system-id of the neighbor.";
       }
    feature prefix-tag64
       leaf metric {
         type wide-metric;
         description
            "Add 64bit tag to prefixes";
          "This leaf describes the ISIS metric value";
       }
    feature reference-bandwidth
       list adjacency-segment-id {
         key value;
         uses adjacency-segment-id;
         description
            "Use a reference bandwidth to compute metric.";
          "List of adjacency-segment-id.";
       }
    feature ipv4-router-id
     }

     grouping neighbor {
       description
         "Support
        "This group defines attributes of IPv4 router ID configuration under ISIS."; an
         ISIS standard neighbor.";
       leaf neighbor-id {
         type system-id;
         description
          "This leaf describes the system-id of the neighbor.";
       }

    feature ipv6-router-id
       leaf i-e {
         type boolean;
         description
         "Support
          "This leaf expresses the value of IPv6 router ID configuration under ISIS."; I/E bit.";
       }

    feature multi-topology
       leaf default-metric {
         type std-metric;
         description
         "Multitopology routing support.";
          "This leaf describes the ISIS default metric value";
       }
    feature nlpid-control
       container delay-metric {
         leaf metric {
           type std-metric;
           description
            "This feature controls leaf describes the advertisement
          of support NLPID within ISIS configuration."; delay metric value";
         }
    feature graceful-restart
         leaf supported {
           type boolean;
           default "false";
           description
            "Graceful restart support as per RFC5306.";
            "This leaf describes if the metric is supported.";
         }

    feature lsp-refresh {
         description
            "Configuration of LSP refresh interval.";
          "This container defines the ISIS delay metric.";
       }

    feature maximum-area-addresses
       container expense-metric {
         leaf metric {
           type std-metric;
           description
            "Support of maximum-area-addresses config.";
            "This leaf describes the ISIS delay expense value";
         }
    typedef instance-state-ref
         leaf supported {
           type leafref {
            path "/rt:routing-state/rt:routing-instance/"
            +"rt:routing-protocols/rt:routing-protocol/rt:name";
        } boolean;
           default "false";
           description
            "This type leaf describes if the metric is used for leaves that reference state data of
          an supported.";
         }
         description
          "This container defines the ISIS protocol instance."; expense metric.";
       }

    typedef admin-state {
        type enumeration
       container error-metric {
            enum "up"
         leaf metric {
           type std-metric;
           description
                 "Up state";
            "This leaf describes the ISIS error metric value";
         }
            enum "down"
         leaf supported {
           type boolean;
           default "false";
           description
                 "Down state";
            "This leaf describes if the metric is supported.";
         }
         description
          "This container defines the ISIS error metric.";
       }
     }

     grouping database {
       description
         "Administrative state
        "This group defines attributes of a component.";
    }
    typedef oper-state an
         ISIS database (Link State DB).";
       leaf lsp-id {
         type enumeration {
            enum "up" { lsp-id;
         description
                 "Up state";
          "This leaf describes the LSP ID of the LSP.";
       }
            enum "down"
       leaf checksum {
         type uint16;
         description
                 "Down state";
            }
        }
        description
         "Operational state
          "This leaf describes the checksum of a component."; the LSP.";
       }
    typedef circuit-id
       leaf remaining-lifetime {
         type uint8; uint16;
         units "seconds";
         description
          "This type defines leaf describes the circuit ID
         associated with an interface."; remaining lifetime
           in seconds before the LSP expiration.";
       }

    typedef extended-circuit-id
       leaf sequence {
         type uint32;
         description
          "This type defines leaf describes the extended circuit ID
         associated with an interface."; sequence number of the LSP.";
       }

    typedef interface-type
       leaf attributes {
         type enumeration bits {
            enum broadcast
           bit PARTITIONNED {
             description "Broadcast interface type.
                Would result in DIS election.";
              "If set, the originator supports partition
               repair.";
           }
            enum point-to-point
           bit ATTACHED-ERROR {
             description
                 "Point
              "If set, the originator is attached to point interface type.";
            }
               another area using the referred metric.";
           }
           bit ATTACHED-EXPENSE {
             description
         "This type defines the type of adjacency
         to be established on
              "If set, the interface.
         This originator is affecting attached to
               another area using the type of hello
         message that would be used."; referred metric.";
           }
    typedef authentication-type {
        type enumeration {
                enum    none
           bit ATTACHED-DELAY {
             description "No authentication used.";
              "If set, the originator is attached to
               another area using the referred metric.";
           }
                enum    plaintext
           bit ATTACHED-DEFAULT {
             description "Plain text password used.";
              "If set, the originator is attached to
               another area using the referred metric.";
           }
                enum    message-digest
           bit OVERLOAD {
             description "MD5 digest used.";
                }
              "If set, the originator is overloaded,
               and must be avoided in path calculation.";
           }
        description
        "This type defines available authentication types.";
         }

    typedef level {
        type enumeration {
            enum "level-1" {
         description
          "This enum leaf describes L1 only capability."; attributes of the LSP.";
       }
            enum "level-2"

       container is-neighbor {
                description
                 "This enum describes L2 only capability.";
            }
            enum "level-all"
         list neighbor {
           key "neighbor-id";
           uses neighbor;
           description
                 "This enum describes both levels capability.";
            }
            "List of neighbors.";
         }
        default "level-all";
         description
          "This type defines ISIS level leaf describes list of an object."; ISIS neighbors.
          ISIS reference is TLV 2.";
       }

    typedef level-number

       container authentication {
        type uint8
         leaf authentication-type {
            range "1 .. 2";
        }
           type authentication-type;
           description
            "This leaf describes the authentication type defines a current ISIS level.";
             to be used.";
         }

    typedef lsp-id
         leaf authentication-key {
           type string {
            pattern
             '[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]'
             +'{4}\.[0-9][0-9]-[0-9][0-9]'; string;
           description
            "This leaf describes the authentication key
             to be used. For security reason, the
             authentication key MUST NOT be presented
             in plaintext format. Authors recommends
             to use MD5 hash to present the authentication-key.";
         }
         description "This type defines container describes authentication
         information of the node. ISIS LSP ID using pattern,
          system id looks like : 0143.0438.AeF0.02-01"; reference is TLV 10.";
       }

    typedef area-address

       container extended-is-neighbor {
        type string
         list neighbor {
            pattern '[0-9A-Fa-f]{2}\.([0-9A-Fa-f]{4}\.){0,3}';
           key "neighbor-id";
           uses neighbor-extended;
           description
            "List of neighbors.";
         }
         description
          "This type defines the area address."; container describes list of ISIS extended
          neighbors.
          ISIS reference is TLV 22.";
       }

    typedef snpa

       container ipv4-internal-reachability {
        type string
         list prefixes {
            length "0 .. 20";
           key "ip-prefix";
           uses prefix-ipv4-std;
           description
            "List of prefixes.";
         }
         description
          "This type defines Subnetwork Point container describes list of Attachement format."; IPv4 internal
          reachability information.
          ISIS reference is TLV 128.";
       }
    typedef system-id

       leaf-list protocol-supported {
         type string {
            pattern
             '[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.[0-9A-Fa-f]{4}\.00';
        } uint8;
         description
          "This type defines leaf describes the list of
          supported protocols.
          ISIS system id using pattern,
          system id looks like : 0143.0438.AeF0.00"; reference is TLV 129.";
       }

    typedef wide-metric

       container ipv4-external-reachability {
        type uint32
         list prefixes {
            range "0 .. 16777215";
           key "ip-prefix";
           uses prefix-ipv4-std;
           description
            "List of prefixes.";
         }
         description
          "This type defines wide style format container describes list of IPv4 external
          reachability information.
          ISIS metric."; reference is TLV 130.";
       }

    typedef std-metric

       leaf-list ipv4-addresses {
         type uint8 {
            range "0 .. 63";
        } inet:ipv4-address;
         description
           "This type defines old style format leaf describes the IPv4 addresses of the node.
           ISIS metric."; reference is TLV 132.";
       }

    typedef mesh-group-state

       leaf ipv4-te-routerid {

         type enumeration {
            enum "meshInactive" { inet:ipv4-address;
         description
                 "Interface is not part
           "This leaf describes the IPv4 Traffic Engineering
           router ID of a mesh group.";
            }
            enum "meshSet" {
                description
                 "Interface the node.
           ISIS reference is part of a mesh group."; TLV 134.";
       }
            enum "meshBlocked"

       container extended-ipv4-reachability {

         list prefixes {
           key "ip-prefix";
           uses prefix-ipv4-extended;
           description
                 "LSPs must not be flooded over that interface.";
            }
            "List of prefixes.";
         }
         description
          "This type container describes meshgroup state list of an interface"; IPv4 extended
          reachability information.
          ISIS reference is TLV 135.";
       }

    grouping notification-instance-hdr {
        description
         "This group describes common instance specific
          data for notifications.";

       leaf instance-name dynamic-hostname {
         type string;

         description
             "Describes
          "This leaf describes the name of the node.
          ISIS instance."; reference is TLV 137.";

       }

       leaf instance-level ipv6-te-routerid {
         type level; inet:ipv6-address;
         description
             "Describes
          "This leaf describes the ISIS level IPv6 Traffic Engineering
           router ID of the instance.";
        } node.
           ISIS reference is TLV 140.";
       }

    grouping notification-interface-hdr

       container mt-is-neighbor {
        description
         "This group describes common interface specific
          data for notifications.";
         list neighbor {
           key "neighbor-id";
           leaf interface-name MT-ID {
             type string; uint16 {
               range "0 .. 4095";
             }
             description
             "Describes
              "This leaf defines the name identifier
               of a topology.";
           }
           uses neighbor-extended;
           description
            "List of neighbors.";
         }
         description
          "This container describes list of the ISIS interface."; multi-topology
           neighbors.
           ISIS reference is TLV 223.";
       }

       container mt-entries {
         list topology {
           key "MT-ID";

           leaf interface-level MT-ID {
             type level; uint16 {
               range "0 .. 4095";
             }
             description
             "Describes
              "This leaf defines the ISIS level identifier
               of the interface."; a topology.";
           }

           leaf extended-circuit-id attributes {
             type extended-circuit-id; bits {
               bit OVERLOAD {
                 description
             "Describes
                  "If set, the originator is overloaded,
                   and must be avoided in path
                   calculation.";
               }
               bit ATTACHED {
                 description
                  "If set, the extended circuit-id of originator is attached to
                   another area using the interface."; referred metric.";
               }
             }

    grouping route-content {
             description
              "This group add isis-specific route properties."; leaf metric {
            type uint32; describes attributes of the LSP
               for the associated topology.";
           }
           description
            "List of topologies supported.";
         }
         description
          "This leaf container describes the topology supported.
          ISIS metric of a route."; reference is TLV 229.";
       }

       leaf-list tag ipv6-addresses {
         type uint64; inet:ipv6-address;
         description
          "This leaf describes list the IPv6 interface
          addresses of tags associated
              with the route. The leaf describes both
              32bits and 64bits tags."; node.
          ISIS reference is TLV 232.";
       }

       container mt-extended-ipv4-reachability {
         list prefixes {
           key "ip-prefix";
           leaf route-type MT-ID {
             type enumeration {
                enum l2-up-internal uint16 {
                    description "Level 2 internal route
                     and not leaked to a lower level";
               range "0 .. 4095";
             }
                enum l1-up-internal {
             description "Level 1 internal route
                     and not leaked to
              "This leaf defines the identifier
               of a lower level"; topology.";
           }
                enum l2-up-external {
           uses prefix-ipv4-extended;
           description "Level 2 external route
                     and not leaked to a lower level";
            "List of prefixes.";

         }
                enum l1-up-external {
         description "Level 1 external route
                     and not leaked to a lower level";
          "This container describes list of IPv4
          reachability information in multi-topology
          environment.
          ISIS reference is TLV 235.";
       }
                enum l2-down-internal

       container mt-ipv6-reachability {
                    description "Level 2 internal route
                     and leaked to a lower level";
                }
                enum l1-down-internal
         list prefixes {
                    description "Level 1 internal route
                     and leaked to a lower level";
                }
                enum l2-down-external
           key "ip-prefix";
           leaf MT-ID {
                    description "Level 2 external route
                     and leaked to a lower level";
                }
                enum l1-down-external
             type uint16 {
               range "0 .. 4095";
             }
             description "Level 1 external route
                     and leaked to
              "This leaf defines the identifier
               of a lower level"; topology.";
           }
           uses prefix-ipv6-extended;
           description
            "List of prefixes.";
         }
         description
          "This leaf container describes the type list of IPv6
          reachability information in multi-topology
          environment.
          ISIS route.";
        } reference is TLV 237.";
       }

    augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route"

       container ipv6-reachability {
        when "rt:source-protocol = 'isis:isis'"
         list prefixes {
           key "ip-prefix";
           uses prefix-ipv6-extended;
           description "ISIS-specific route attributes.";
            "List of prefixes.";
         }
        uses route-content;
         description
          "This augments route object in RIB with ISIS-specific
          attributes."; container describes list of IPv6
          reachability information.
          ISIS reference is TLV 236.";
       }

    augment "/rt:active-route/rt:output/rt:route"

       list segment-routing-bindings {
        uses route-content;
         if-feature segment-routing;
         key "fec range";

         leaf fec {
           type string;
           description "ISIS-specific route attributes.";
           "IP (v4 or v6) range to be bound to SIDs.";
         }

    grouping prefix-ipv4-std

         leaf range {
           type uint16;
           description
         "This group defines attributes
            "Describes number of an
          IPv4 standard prefix."; elements to assign
            a binding to.";
         }

         leaf up-down flags {
           type boolean; bits {
             bit address-family {
               position 7;
               description
             "This leaf expresses
               "If unset, then the value of up/down bit."; Prefix FEC
               carries an IPv4 Prefix.
               If set then the Prefix FEC carries an
               IPv6 Prefix.";
             }
        leaf i-e
             bit mirror {
            type boolean;
               position 6;
               description
             "This leaf expresses
               "Set if the value of I/E bit."; advertised SID/path
               corresponds to a mirrored context.
               ";
             }
        leaf ip-prefix
             bit flooding {
            type inet:ipv4-address;
               position 5;
               description
             "This leaf describes
                "If the IPv4 prefix"; S bit is set(1),
                the IS-IS Router CAPABILITY TLV
               MUST be flooded across the entire routing domain.
               If the S bit is
               not set(0), the TLV MUST NOT be leaked between levels.
               This bit MUST NOT be altered during the TLV leaking.";
             }
        leaf prefix-len
             bit down {
            type uint8;
               position 4;
               description
               "When the IS-IS Router CAPABILITY TLV is
               leaked from level-2 to level-1, the D bit
               MUST be set.  Otherwise, this bit MUST
               be clear.  IS-IS Router capability TLVs
               with the D bit set MUST NOT
               be leaked from level-1 to level-2.

               This is to prevent TLV looping.
               ";
             }
             bit attached {
               position 3;
               description
               "The originator of the SID/Label Binding
               TLV MAY set the A bit in order to signal
               that the prefixes and
               SIDs advertised in the SID/Label Binding
               TLV are directly
               connected to their originators.
               ";
             }

           }
           description
             "This leaf describes
              "Flags of the IPv4 prefix len in bits"; binding.";
         }

         leaf default-metric weight {
           type std-metric; uint8;
           description
             "This leaf describes
            "Weight of the ISIS default metric value"; path for loadbalancing purpose.";
         }
        container delay-metric

         list binding {
            leaf metric
           container prefix-sid {
                type std-metric;
             uses prefix-segment-id;
             description
                 "This leaf describes
              "Binding prefix SID to the ISIS delay metric value"; range.";
           }
           leaf supported ero-metric {
             type boolean;
                default "false";
                description
                 "This leaf describes if the metric is supported.";
            } uint32;
             description
             "This container defines the ISIS delay metric.";
              "Cost of ERO path.";
           }
           container expense-metric ero {
             leaf metric address-family {
               type std-metric; identityref {
                 base rt:address-family;
               }
               description
                 "This leaf describes the ISIS expense metric value";
                "Address-family.";
             }

             leaf supported loose {
               type boolean;
                default "false";
               description
                 "This leaf describes
                "Set to true,
                if the metric hop is supported."; a loose hop.";
             }
             leaf address {
               type string;
               description
             "This container defines
               "IP address of a node on the ISIS expense metric.";
               path.";
             }

             description
              "Binding ERO path to the range.";
           }
           container error-metric backup-ero {
             leaf metric address-family {
               type std-metric; identityref {
                 base rt:address-family;
               }
               description
                 "This leaf describes the ISIS error metric value";
                "Address-family.";
             }

             leaf supported loose {
               type boolean;
                default "false";
               description
                 "This leaf describes
                "Set to true,
                if the metric hop is supported."; a loose hop.";
             }
             leaf address {
               type string;
               description
             "This container defines
               "IP address of a node on the ISIS error metric.";
               path.";
             }

             description
              "Binding backup ERO path to the range.";
           }

    grouping prefix-ipv4-extended
           container unnumbered-interface-id-ero {
        description
         "This group defines attributes of an
          IPv4 extended prefix.";
             leaf up-down router-id {
               type boolean; string;
               description
             "This leaf expresses the value
                "Router ID of up/down bit."; the node owning the interface.";
             }
             leaf ip-prefix interface-id {
               type inet:ipv4-address; uint32;
               description
             "This leaf describes
               "Interface ID on which the IPv4 prefix"; path is built.";
             }
             description
              "Binding a path over unnumbered interface.";
           }
           container backup-unnumbered-interface-id-ero {
             leaf prefix-len router-id {
               type uint8; string;
               description
             "This leaf describes
                "Router ID of the IPv4 prefix len in bits"; node owning the interface.";
             }
             leaf metric interface-id {
               type wide-metric; uint32;
               description
             "This leaf describes
               "Interface ID on which the ISIS metric value"; path is built.";
             }
        leaf-list tag {
            type uint32;
             description
             "This leaf describes
              "Binding a list of tags backup path over unnumbered interface.";
           }
           description
            "Bindings associated with the prefix."; range.";
         }
        leaf-list tag64 {
            type uint64;

         description
          "This leaf container describes a list of 64-bit tags associated with
             the prefix.";
        } SID/Label
          bindings.
          ISIS reference is TLV 149.";
       }

    grouping prefix-ipv6-extended

       list router-capabilities {
        description
         "This group defines attributes of an
          IPv6 prefix.";
         leaf up-down flags {
           type boolean; bits {
             bit flooding {
               position 0;
               description
             "This leaf expresses
                "If the value of up/down bit."; S bit is set(1),
                the IS-IS Router CAPABILITY TLV
               MUST be flooded across the entire routing domain.
               If the S bit is
               not set(0), the TLV MUST NOT be leaked between levels.
               This bit MUST NOT be altered during the TLV leaking.";
             }
        leaf ip-prefix
             bit down {
            type inet:ipv6-address;
               position 1;
               description
             "This leaf describes
               "When the IPv6 prefix"; IS-IS Router CAPABILITY TLV is
               leaked from level-2 to level-1, the D bit
               MUST be set.  Otherwise, this bit MUST
               be clear.  IS-IS Router capability TLVs
               with the D bit set MUST NOT
               be leaked from level-1 to level-2.
               This is to prevent TLV looping.
               ";
             }
           }
           description
            "Flags associated with router capability.";
         }
         container node-tag {
           if-feature node-tag;
           list node-tag {
             leaf prefix-len tag {
               type uint8; uint32;
               description
             "This leaf describes the IPv4 prefix len in bits";
                "Node tag value.";
             }
             description
              "List of tags.";
           }
           description
            "Container for node tags.";
         }
         list segment-routing {
           leaf metric flags {
             type wide-metric; bits {
               bit ipv4 {
                 position 7;
                 description
             "This leaf describes
                 "If set, then the ISIS metric value"; router is capable of
                 outgoing IPv4 encapsulation on all interfaces.
                 ";

               }
        leaf-list tag
               bit ipv6 {
            type uint32;
                 position 6;
                 description
             "This leaf describes a list of tags associated with
                 "If set, then the prefix."; router is capable of
                 outgoing IPv6 encapsulation on all interfaces.
                 ";
               }
             }
        leaf-list tag64 {
            type uint64;
             description
             "This leaf describes a list of 64-bit tags
              "Flags associated with the prefix.";
        } capability.";
           }

    grouping neighbor-extended {
        description
         "This group defines attributes of an
          ISIS extended neighbor.";
           leaf neighbor-id range {
             type system-id; uint32;
             description
             "This leaf describes the system-id
              "Number of values of the neighbor."; range starting with the
              SID/Label value.";
           }
           leaf metric starting-value {
             type wide-metric; uint32;
             description
             "This leaf describes
             "Lower bound of the ISIS metric value"; label block.";
           }
           description
            "Segment routing capability.";
         }

    grouping neighbor
         leaf-list segment-routing-algorithm {
           type uint8;
           description
         "This group defines attributes
            "List of an
          ISIS standard neighbor."; supported algorithm for segment routing.";
         }
         leaf neighbor-id binary {
           type system-id; binary;
           description
            "This leaf describes the system-id capability of the neighbor."; node.
            Format is binary according to the protocol encoding.";
         }
        leaf i-e {
            type boolean;
         description
          "This leaf expresses container describes the value capabilities of I/E bit."; the node.
          This container may be extended with detailed
          information.
          ISIS reference is TLV 242.";
       }
        leaf default-metric
     }

     /* */

     augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" {
       when "rt:source-protocol = 'isis:isis'" {
            type std-metric;
         description "ISIS-specific route attributes.";
       }
       uses route-content;
       description
        "This leaf describes the ISIS default metric value"; augments route object in RIB with ISIS-specific
         attributes.";
       }
        container delay-metric

     augment "/rt:active-route/rt:output/rt:route"
        {
       uses route-content;
       description "ISIS-specific route attributes.";
       }

     augment "/if:interfaces/if:interface"
        {
       leaf metric clns-mtu {
         type std-metric; uint16;
         description
                 "This leaf describes
          "Defines CLNS MTU of the ISIS delay metric value"; interface.";
       }
            leaf supported
       description "ISO interface config.";
       }

     augment "/rt:routing/rt:routing-instance/rt:routing-protocols/"
         +"rt:routing-protocol" {
       when "rt:type = 'isis:isis'" {
                type boolean;
                default "false";
         description
          "This leaf describes if the metric augment is supported."; only valid when routing protocol
           instance type is isis.";
       }
       description
        "This container defines the augments a routing protocol instance with ISIS delay metric.";
        }
         specific parameters.";
       container expense-metric isis {

         list instance {
           must "count(area-address) > 0" {
             error-message "At least one area-address
             must be configured.";
             description
              "Enforce configuration of at least one area.";
           }

           key routing-instance;

           leaf metric routing-instance {
             type std-metric; rt:routing-instance-ref;
               description
                 "This leaf describes
               "Reference routing instance.
               For protocol centric model, which is
               supported in
               default-instance only, this could reference
               any VRF routing-instance.
               For VRF centric model, must reference the ISIS delay expense value";
               enclosing routing-instance.";
           }

           leaf supported level-type {
             type boolean; level;
             default "false"; "level-all";
             description
              "This leaf describes if the metric is supported.";
            }
            description
             "This container defines the type of ISIS expense metric."; node.
              A node can be level-1-only, level-2-only
              or level-1-2.
              ";
           }
        container error-metric {

           leaf metric system-id {
             type std-metric; system-id;
             description
              "This leaf describes defines the ISIS error metric value"; system-id of the node.";
           }

           leaf supported maximum-area-addresses {
             if-feature maximum-area-addresses;
             type boolean; uint8;
             default "false"; 3;
             description
                 "This leaf describes if
              "Defines the metric is maximum areas supported.";
           }

           leaf-list area-address {
             type area-address;
             description
             "This container defines
              "List of areas supported by the ISIS error metric.";
        }
              protocol instance.";
           }

    grouping database

           container mpls {
        description
         "This group defines attributes of an
          ISIS database (Link State DB).";
             leaf lsp-id ipv4-router-id {
               if-feature ipv4-router-id;
               type lsp-id; inet:ipv4-address;
               description
             "This leaf describes the LSP
                "Router ID of the LSP."; value that would be used in
                TLV 134.";
             }
             leaf checksum ipv6-router-id {
               if-feature ipv6-router-id;
               type uint16; inet:ipv6-address;
               description
                "Router ID value that would be used in
                TLV 140.";
             }
             container igp-ldp-sync {
               if-feature igp-ldp-sync;
               description
                 "This leaf describes the checksum of the LSP."; container may be augmented
                 with global parameters for igp-ldp-sync.";
             }
             description
               "This container handles mpls config.";
           }
           leaf remaining-lifetime reference-bandwidth {
             if-feature reference-bandwidth;
             type uint16; uint32;
             units "seconds"; "bps";
             description
              "This leaf describes the remaining lifetime
              in seconds before defines the LSP expiration."; bandwidth for calculating
               metric.";
           }

           leaf sequence lsp-mtu {
             type uint32; uint16;
             units "bytes";
             default 1492;
             description
              "This leaf describes the sequence number maximum size of the LSP."; a
               LSP PDU in bytes.";
           }
           leaf attributes lsp-lifetime {
             type bits {
                bit PARTITIONNED {
                    description
                     "If set, the originator supports partition
                      repair.";
                }
                bit ATTACHED-ERROR {
                    description
                     "If set, the originator is attached to
                      another area using the referred metric.";
                }
                bit ATTACHED-EXPENSE {
                    description
                     "If set, the originator is attached to
                      another area using the referred metric.";
                }
                bit ATTACHED-DELAY { uint16;
             units "seconds";
             description
                     "If set,
              "This leaf describes the originator is attached to
                      another area using lifetime of the referred metric."; router
               LSP in seconds.";
           }
                bit ATTACHED-DEFAULT
           leaf lsp-refresh {
             if-feature lsp-refresh;
             type uint16;
             units "seconds";
             description
                     "If set,
              "This leaf describes the originator is attached to
                      another area using refresh interval of the referred metric.";
               router LSP in seconds.";
           }
                bit OVERLOAD

           container graceful-restart {
             if-feature graceful-restart;
             leaf enabled {
               type boolean;
               description
                     "If set,
                "Control enabling the originator is overloaded,
                      and must be avoided in path calculation.";
                } feature.";
             }
             description
              "This leaf describes attributes of the LSP."; container activates graceful restart.";
           }

           container is-neighbor node-tag {
             if-feature node-tag;

             list neighbor node-tag {
               key "neighbor-id";
                uses neighbor; tag;
               leaf tag {
                 type uint32;
                 description
                  "Node tag value.";
               }
               description
                "List of neighbors."; tags.";
             }
             description
             "This leaf describes list of ISIS neighbors.
             ISIS reference is TLV 2.";
               "Container for node tags.";
           }

        container

           uses fast-reroute-global-cfg;

           uses segment-routing-global-cfg;

           list authentication {
             key level;

             leaf authentication-type key {
               type authentication-type; string;
               description
                "This leaf describes the
                authentication type
                  to be used."; key.";
             }
             leaf authentication-key type {
               type string; authentication-type;
               description
                "This leaf describes the authentication key
                 type to be used. For security reason, the
                  authentication key MUST NOT be presented
                  in plaintext format. Authors recommends
                  to use MD5 hash to present the authentication-key."; used.";
             }
             leaf level {
               type level;
               description "This container describes authentication
            information of the node.
                 "Level applicability.";
             }
             description
              "Container for ISIS reference is TLV 10."; authentication.
               It covers both LSPs and SNPs.";

           }

        container extended-is-neighbor {

           list neighbor metric-type {
             key "neighbor-id";
                uses neighbor-extended; level;

             leaf value {
               type enumeration {
                 enum wide-only {
                   description
                 "List of neighbors.";
                    "Advertise new metric style only
                    (RFC5305)";
                 }
                 enum old-only {
                   description
             "This container describes list of ISIS extended
             neighbors.
             ISIS reference is TLV 22.";
                    "Advertise old metric style only
                    (RFC1195)";
                 }

        container ipv4-internal-reachability {
            list prefixes
                 enum both {
                key "ip-prefix";
                uses prefix-ipv4-std;
                   description
                 "List of prefixes."; "Advertise both metric
                   styles";
                 }
            description
             "This container describes list of IPv4 internal
             reachability information.
             ISIS reference is TLV 128.";
               }

        leaf-list protocol-supported {
            type uint8;
               description
                "This leaf describes the list type of
             supported protocols.
             ISIS reference metric
                to be generated.
                Wide-only means only new metric style
                is TLV 129."; generated,
                old-only means that only old style metric
                is generated,
                and both means that both are advertised.
                This leaf is only affecting IPv4 metrics.";
             }

        container ipv4-external-reachability {
            list prefixes
             leaf level {
                key "ip-prefix";
                uses prefix-ipv4-std;
               type level;
               description
                 "List of prefixes.";
                 "Level applicability.";
             }
             description
             "This container describes list of IPv4 external
             reachability information.
             ISIS reference is TLV 130.";
              "Metric style container.";
           }

        leaf-list ipv4-addresses
           list preference {
             key level;

             choice granularity {
               case detail {
                 leaf internal {
                   type inet:ipv4-address; uint8;
                   description
                     "This leaf describes the IPv4 addresses of defines the node.
                ISIS reference is TLV 132."; protocol
                      preference for internal routes.";
                 }
                 leaf ipv4-te-routerid external {
                   type inet:ipv4-address; uint8;
                   description
                     "This leaf describes the IPv4 Traffic Engineering
                router ID of defines the node.
                ISIS reference is TLV 134.";
        }

        container extended-ipv4-reachability {

            list prefixes {
                key "ip-prefix";
                uses prefix-ipv4-extended;
                description
                 "List of prefixes."; protocol
                      preference for external routes.";
                 }
            description
             "This container describes list of IPv4 extended
             reachability information.
             ISIS reference is TLV 135.";
               }
               case coarse {
                 leaf dynamic-hostname default {
                   type string; uint8;
                   description
                     "This leaf describes the name of defines the node. protocol
                      preference for all ISIS reference is TLV 137."; routes.";
                 }
               }
               description
                "Choice for implementation of route preference.";
             }

             leaf ipv6-te-routerid level {
               type inet:ipv6-address; level;
               description
                 "Level applicability.";
             }
             description
                "This leaf describes the IPv6 Traffic Engineering
              router ID of defines the node.
              ISIS reference is TLV 140.";
        }

        container mt-is-neighbor { protocol preference.";
           }

           list neighbor default-metric {
             key "neighbor-id"; level;

             leaf MT-ID value {
               type uint16 {
                        range "0 .. 4095";
                    } wide-metric;
               description
                     "This leaf defines the identifier
                 "Value of a topology."; the metric";
             }
                uses neighbor-extended;
             leaf level {
               type level;
               description
                 "List
                 "Level applicability of neighbors."; the metric.";
             }
             description
             "This container describes list of ISIS multi-topology
              neighbors.
              ISIS reference is TLV 223.";
              "Defines the metric to be used by default.";

           }

        container mt-entries {
           list topology af {
             if-feature nlpid-control;
             key "MT-ID"; af;
             leaf MT-ID af {
               type uint16 identityref {
                        range "0 .. 4095";
                 base rt:address-family;
               }
               description
                     "This leaf defines the identifier
                      of a topology.";
                "Address-family";
             }

             leaf attributes enabled {
               type bits {
                        bit OVERLOAD {
                            description
                             "If set, the originator is overloaded,
                              and must be avoided in path
                              calculation.";

                        }
                        bit ATTACHED { boolean;
               description
                             "If set,
                 "Describes the originator is attached to
                              another area using activation state of the referred metric.";
                        }
                  AF.";
             }
             description
              "This leaf describes attributes list permits activation
              of the LSP
                      for the associated topology."; new address families.";

           }
                description
                 "List of

           list topologies supported.";
            }
            description
             "This container describes the topology supported.
             ISIS reference is TLV 229.";
        }

        leaf-list ipv6-addresses {
             if-feature multi-topology;

             key "name";
             leaf enabled {
               type inet:ipv6-address; boolean;
               description
             "This leaf describes
                 "Describes the IPv6 interface
             addresses activation state of the node.
             ISIS reference is TLV 232.";
                  AF.";
             }

        container mt-extended-ipv4-reachability
             leaf name {
               type rt:rib-ref;
               description "RIB";
             }

             uses fast-reroute-global-cfg;
             uses segment-routing-global-cfg;

             list prefixes default-metric {
               key "ip-prefix"; level;

               leaf MT-ID value {
                 type uint16 {
                        range "0 .. 4095";
                    } wide-metric;
                 description
                     "This leaf defines the identifier
                   "Value of a topology."; the metric";
               }
                uses prefix-ipv4-extended;
               leaf level {
                 type level;
                 description
                 "List
                   "Level applicability of prefixes."; the metric.";
               }
               description
             "This container describes list of IPv4
             reachability information in multi-topology
             environment.
             ISIS reference is TLV 235.";
                "Defines the metric to be used by default.";
             }
             container mt-ipv6-reachability node-tag {
               if-feature node-tag;
               list prefixes node-tag {
                 key "ip-prefix"; tag;
                 leaf MT-ID tag {
                   type uint16 {
                        range "0 .. 4095";
                    } uint32;
                   description
                     "This leaf defines the identifier
                      of a topology.";
                    "Node tag value.";
                 }
                uses prefix-ipv6-extended;
                 description
                  "List of prefixes."; tags.";
               }
               description
             "This container describes list of IPv6
             reachability information in multi-topology
             environment.
             ISIS reference is TLV 237.";
                 "Container for node tags.";
             }

        container ipv6-reachability {
            list prefixes {
                key "ip-prefix";
                uses prefix-ipv6-extended;
             description
               "List of prefixes."; topologies";
           }
            description
             "This container describes

           list of IPv6
             reachability information.
             ISIS reference is TLV 236.";
        }

        container router-capabilities overload {
             key level;

             leaf binary status {
               type binary; boolean;
               description
                "This leaf describes the capability of the node.
                 Format is binary according to defines the protocol encoding."; overload status.";
             }

             leaf timeout {
               type uint16;
               units "seconds";
               description
                "This container describes leaf defines the capabilities timeout in seconds
                 of the node.
             This container may be extended with detailed
             information.
             ISIS reference is TLV 242.";
        } overload condition.";
             }

    augment "/rt:routing/rt:routing-instance/rt:routing-protocols/"
        +"rt:routing-protocol" {
        when "rt:type = 'isis:isis'"
             leaf level {
            description
             "This augment is only valid when routing protocol
              instance
               type is isis.";
        }
        description
         "This augments a routing protocol instance with ISIS
          specific parameters.";
        container isis {

            list instance {
                must "count(area-address) > 0" {
                    error-message "At least one area-address
                    must be configured."; level;
               description
                     "Enforce configuration
                 "Level applicability of at least one area."; the metric.";
             }

                key routing-instance;

                leaf routing-instance {
                    type rt:routing-instance-ref;
             description
                        "Reference routing instance.
                        For protocol centric model, which is
                        supported in
                        default-instance only, this could reference
                        any VRF routing-instance.
                        For VRF centric model, must reference
              "This leaf describes if the
                        enclosing routing-instance."; router is
               set to overload state.";
           }

                leaf level-type

           list overload-max-metric {
                    type
             if-feature overload-max-metric;
             key level;
                    default "level-all";

             leaf status {
               type boolean;
               description
                "This leaf describes defines the type of ISIS node.
                     A node can be level-1-only, level-2-only
                     or level-1-2.
                     "; overload status.";
             }

             leaf system-id timeout {
               type system-id; uint16;
               units "seconds";
               description
                "This leaf defines the system-id timeout in seconds
                 of the node."; overload condition.";
             }
             leaf maximum-area-addresses level {
                    if-feature maximum-area-addresses;
               type uint8;
                    default 3; level;
               description
                     "Defines
                 "Level applicability of the maximum areas supported."; metric.";
             }

                leaf-list area-address {
                    type area-address;
             description
                     "List of areas supported by
              "This leaf describes if the
                     protocol instance."; router is
               set to overload state.";
           }

           container mpls-te {
                    leaf ipv4-router-id interfaces {
                        if-feature ipv4-router-id;
                        type inet:ipv4-address;
                        description
                         "Router ID value that would be used in
                         TLV 134.";
                    }
                    leaf ipv6-router-id
             list interface {
                        if-feature ipv6-router-id;
                        type inet:ipv6-address;
                        description
                         "Router ID value that would be used in
                         TLV 140.";
                    }
                    description
                        "This container handles mpls te config.";
                }
               key "name";
               leaf reference-bandwidth name {
                    if-feature reference-bandwidth;
                 type uint32;
                    units "bps"; if:interface-ref;

                 description
                     "This leaf defines
                  "Reference to the bandwidth for calculating
                      metric."; interface within
                   the routing-instance.";
               }
               leaf lsp-mtu level-type {
                 type uint16;
                    units "bytes"; level;
                 default 1492; "level-all";
                 description
                  "This leaf describes defines the maximum size associated ISIS
                  level of a
                      LSP PDU in bytes."; the interface.";
               }
               leaf lsp-lifetime lsp-pacing-interval {
                 type uint16;
                 units "seconds"; "milliseconds";
                 description
                  "This leaf describes the lifetime of defines the router interval between
                   LSP transmissions in seconds."; milli-seconds";
               }
               leaf lsp-refresh lsp-retransmit-interval {
                    if-feature lsp-refresh;
                 type uint16;
                 units "seconds";
                 description
                  "This leaf describes defines the refresh interval between
                  retransmission of the
                      router LSP in seconds."; LSP";
               }

                container graceful-restart {
                    if-feature graceful-restart;
               leaf enabled passive {
                 type boolean;
                        description
                         "Control enabling the feature.";
                    }
                    description
                     "This container activates graceful restart.";
                }

                list authentication {
                    key level;

                    leaf key {
                        type string;
                 default "false";
                 description
                  "This leaf describes the
                         authentication key."; defines if interface is in
                   passive mode (ISIS not running,
                   but network is advertised).";
               }
               leaf type csnp-interval {
                 type authentication-type; uint16;
                 units "seconds";
                 description
                  "This leaf describes defines the authentication
                          type to be used."; interval of CSNP
                   messages.";
               }

               container hello-padding {
                 leaf level enabled {
                   type level; boolean;
                   default "true";
                   description
                            "Level applicability.";
                    "Status of Hello-padding activation.
                     By default, the implementation shall
                     pad HELLOs.";
                 }

                 description
                     "Container for
                  "This container handles ISIS authentication.
                      It covers both LSPs and SNPs."; hello padding
                   configuration.";

               }

                list metric-type {
                    key level;

               leaf value mesh-group-enabled {
                 type enumeration {
                            enum wide-only { mesh-group-state;
                 description
                                 "Advertise new metric style only
                                 (RFC5305)";
                  "Describes the mesh group state of
                   the interface.";
               }
                            enum old-only

               leaf mesh-group {
                                description
                                 "Advertise old metric style only
                                 (RFC1195)";
                            }
                            enum both
                 when "../mesh-group-enabled = meshSet" {
                   description "Advertise both metric
                                styles";
                    "Only valid when mesh-group-enabled
                     equals meshSet";
                 }
                 type uint8;
                 description
                  "Describes the mesh group ID of
                   the interface.";
               }

               leaf interface-type {
                 type interface-type;
                 description
                  "This leaf describes defines the type of metric adjacency
                  to be generated.
                         Wide-only means only new metric style
                         is generated,
                         old-only means that only old style metric
                         is generated,
                         and both means that both are advertised. established on the interface.
                  This leaf is only affecting IPv4 metrics.";
                    }
                    leaf level { the type level;
                        description
                            "Level applicability.";
                    }
                    description
                     "Metric style container."; of hello
                  message that would be used.";
               }
                list preference {
                    key level;

                    choice granularity {
                        case detail {

               leaf internal enabled {
                 type uint8; boolean;
                 default "true";
                 description
                  "This leaf defines describes the protocol
                                     preference for internal routes."; administrative
                  status of the ISIS interface.";

               }
                            leaf external

               leaf-list tag {
                 if-feature prefix-tag;

                 type uint8; uint32;
                 description
                  "This leaf defines list of tags associated
                   with the protocol
                                     preference for external routes.";
                            } interface.";
               }
                        case coarse {
                            leaf default
               leaf-list tag64 {
                 if-feature prefix-tag64;

                 type uint8; uint64;
                 description
                  "This leaf defines the protocol
                                     preference for all ISIS routes.";
                            }
                        }
                        description
                         "Choice for implementation list of route preference."; 64bits tags
                  associated with the interface.";
               }

               list hello-authentication {
                 key level;

                 leaf level type {
                   type level;
                        description
                            "Level applicability.";
                    } authentication-type;

                   description
                    "This leaf defines describes the protocol preference."; authentication
                    type to be used in hello messages.";
                 }

                list default-metric {
                    key level;
                 leaf value key {
                   type wide-metric; string;
                   description
                            "Value of
                    "This leaf describes the metric";
                    authentication key
                    to be used in hello messages.
                    For security reason, the
                    authentication key MUST
                    NOT be presented
                    in plaintext format upon a
                    get-config reply.
                    Authors recommends
                    to use MD5 hash to present the
                    authentication-key";
                 }
                 leaf level {
                   type level;
                   description
                     "Level applicability of the metric."; applicability.";
                 }
                 description
                     "Defines
                  "This leaf describes the metric authentication type
                  to be used by default."; in hello messages.";
               }

               list af hello-interval {
                    if-feature nlpid-control;
                 key af; level;

                 leaf af value {
                   type string; uint16;
                   units "seconds";
                   description
                         "Address-family";
                    "This leaf defines the interval of
                    hello messages.";
                 }
                 leaf enabled level {
                   type boolean; level;
                   description
                            "Describes the activation state of the
                             AF.";
                     "Level applicability.";
                 }
                 description
                    "This list permits activation
                     of new address families.";

                }

                list topologies {
                    if-feature multi-topology;

                    key "name"; leaf enabled {
                        type boolean;
                        description
                            "Describes defines the activation state interval of the
                             AF.";
                    }
                    leaf name {
                        type rt:rib-ref;
                        description "RIB";
                    hello messages.";
               }
               list default-metric hello-multiplier {
                 key level;

                 leaf value {
                   type wide-metric; uint16;
                   description
                                "Value
                    "This leaf defines the number of
                    hello failed to be received before
                    declaring the metric"; adjacency down.";
                 }
                 leaf level {
                   type level;
                   description
                     "Level applicability of the metric."; applicability.";
                 }
                 description
                         "Defines
                    "This leaf defines the metric number of
                     hello failed to be used by default.";
                    }
                    description
                        "List of topologies"; received before
                     declaring the adjacency down.";
               }

               list overload priority {
                    key level;

                    leaf status
                 must 'interface-type = "broadcast"' {
                        type boolean;
                   error-message
                    "Priority only applies to broadcast
                    interfaces.";
                   description
                         "This leaf defines the overload status.";
                    "Check for broadcast interface.";
                 }
                 key level;
                 leaf timeout value {
                   type uint16;
                        units "seconds"; uint8 {
                     range "0 .. 127";
                   }

                   description
                    "This leaf defines describes the timeout in seconds priority of
                    the overload condition."; interface
                    for DIS election.";
                 }
                 leaf level {
                   type level;
                   description
                     "Level applicability of the metric."; applicability.";
                 }
                 description
                    "This leaf describes if the router is
                      set to overload state."; priority of
                    the interface
                    for DIS election.";
               }
               list overload-max-metric metric {
                    if-feature overload-max-metric;
                 key level;

                 leaf status {
                        type boolean;
                        description
                         "This leaf defines the overload status.";
                    }

                    leaf timeout value {
                   type uint16;
                        units "seconds"; wide-metric;
                   description
                         "This leaf defines the timeout in seconds
                          of the overload condition.";
                    "Metric value.";
                 }
                 leaf level {
                   type level;
                   description
                     "Level applicability of the metric."; applicability.";
                 }
                 description
                     "This
                  "Container for interface metric";
               }

               list af {
                 key af;

                 leaf describes if the router is
                      set to overload state."; af {
                   type identityref {
                     base rt:address-family;
                   }
                   description
                     "Address-family";
                 }
                 container interfaces segment-routing {
                   if-feature segment-routing;
                   list interface prefix-sid {
                     key "name"; value;
                     leaf name value-type {
                       type string; enumeration {
                         enum index {
                           description
                             "Reference to the interface within
                              "The value will be
                              interpreted as an index.";

                         }
                         enum absolute {
                           description
                              "The value will become
                              interpreted as an absolute
                              value.";
                         }
                       }
                       description
                         "This leaf defines how value
                          must be interpreted.";
                     }

                     leaf value {
                       type uint32;
                       description
                       "Value associated with
                       prefix. The value must
                       be interpreted in the routing-instance.";
                       context of value-type.";
                     }
                     leaf level-type node-flag {
                       type level; boolean;
                       default "level-all"; true;
                       description
                             "This
                       "Set prefix as a node
                        representative prefix.";
                     }
                     leaf defines last-hop-behavior {
                       type enumeration {
                         enum explicit-null {
                           description
                            "Use explicit-null for the associated ISIS
                             level SID.";
                         }
                         enum no-php {
                           description
                            "Do no use PHP for the SID.";
                         }
                         enum php {
                           description
                            "Use PHP for the SID.";
                         }
                       }
                       description
                        "Configure last hop behavior.";
                     }

                     description
                     "List of prefix-SID associated with
                      the interface.";
                   }
                   description
                    "Segment routing interface configuration.";
                 }
                 container bfd {
                   if-feature bfd;
                   leaf lsp-pacing-interval enabled {
                     type uint16;
                            units "milliseconds"; boolean;
                     default false;
                     description
                      "This leaf defines the interval between
                              LSP transmissions in milli-seconds"; enables BFD.";
                   }

                   description
                     "The container describes
                      BFD config.";
                 }

                 description
                  "List of AFs.";
               }

               list topologies {
                 key name;

                 leaf name {
                   type rt:rib-ref;
                   description
                    "Name of RIB.";
                 }
                 list metric {
                   key level;

                   leaf lsp-retransmit-interval value {
                     type uint16;
                            units "seconds"; wide-metric;
                     description
                             "This leaf defines the interval between
                             retransmission of LSP";
                      "Metric value.";
                   }
                   leaf passive level {
                     type boolean;
                            default "false"; level;
                     description
                             "This leaf defines if
                       "Level applicability.";
                   }
                   description
                    "Container for interface is in
                              passive mode (ISIS not running,
                              but network is advertised)."; metric";
                 }
                        leaf csnp-interval {
                            type uint16;
                            units "seconds";
                 uses fast-reroute-if-cfg;

                 uses segment-routing-if-cfg;

                 description
                             "This leaf defines the interval
                  "List of CSNP
                              messages."; topologies.";
               }

               uses fast-reroute-if-cfg;

               uses segment-routing-if-cfg;

               container hello-padding mpls {
                 container igp-ldp-sync {
                   if-feature igp-ldp-sync;
                   leaf enabled {
                     type boolean;
                                default "true";
                     description
                                 "Status
                      "Enable/disable IGP LDP sync.";
                   }
                   description
                    "IGP-LDP sync configuration.";
                 }
                 description
                  "Container for MPLS specific configuration
                  for ISIS.";
               }
               description
                "List of Hello-padding activation.
                                  By default, the implementation shall
                                  pad HELLOs."; ISIS interfaces.";
             }

             description
              "This container handles defines ISIS hello padding
                              configuration."; interface specific
              configuration objects.";
           }

                        leaf mesh-group-enabled {
                            type mesh-group-state;
           description
                             "Describes the mesh group state
             "List of
                              the interface."; ISIS instances.";
         }

                        leaf mesh-group
         description
          "This container defines ISIS specific configuration
           objects.";
       }
     }

     augment "/rt:routing-state/rt:routing-instance/"
       +"rt:routing-protocols/rt:routing-protocol" {
       when "../mesh-group-enabled "rt:type = meshSet" 'isis:isis'" {
         description
                                 "Only
          "This augment is only valid when mesh-group-enabled
                                  equals meshSet";
                            } routing protocol
           instance type uint8;
                            description
                             "Describes the mesh group ID of
                              the interface."; is isis.";
       }

                        leaf interface-type {
                            type interface-type;
       description
        "This augments routing protocol instance states with ISIS
         specific parameters.";
       container isis {
         config false;
         list instance {

           key routing-instance;

           leaf defines the type of adjacency
                             to be established on the interface.
                             This is affecting the type of hello
                             message that would be used.";
                        }

                        leaf enabled routing-instance {
             type boolean;
                            default "true"; rt:routing-instance-ref;
               description
                             "This leaf describes the administrative
                             status of
               "Reference routing instance.
               For protocol centric model, which is
               supported in
               default-instance only, this could reference
               any VRF routing-instance.
               For VRF centric model, must reference the ISIS interface.";
               enclosing routing-instance.";
           }

                        leaf-list tag
           container fast-reroute {
             if-feature prefix-tag;

                            type uint32;
                            description
                             "This leaf defines list of tags associated
                              with the interface.";
                        }

                        leaf-list tag64 fast-reroute;

             container protected-routes {
                            if-feature prefix-tag64;
                            type uint64;
                            description
                             "This leaf defines list of 64bits tags
                             associated with the interface.";
                        }
               list hello-authentication af-stats {
                 key level; "af prefix alternate";

                 leaf type af {
                   type authentication-type; identityref {
                     base rt:address-family;
                   }
                   description
                                 "This
                    "Address-family";
                 }
                 leaf describes the authentication prefix {
                   type to be used in hello messages."; string;
                   description
                    "Protected prefix.";
                 }
                 leaf key alternate {
                   type string;
                   description
                                 "This leaf describes the
                                 authentication key
                                 to be used in hello messages.
                                 For security reason, the
                                 authentication key MUST
                                 NOT be presented
                                 in plaintext format upon a
                                 get-config reply.
                                 Authors recommends
                                 to use MD5 hash to present
                    "Alternate nexthop for the
                                 authentication-key"; prefix.";
                 }
                 leaf level alternate-type {
                   type level; enumeration {
                     enum equalcost {
                       description
                                    "Level applicability.";
                        "ECMP alternate.";
                     }
                     enum lfa {
                       description
                             "This leaf describes the authentication type
                             to be used in hello messages.";
                        "LFA alternate.";
                     }

                        list hello-interval
                     enum remote-lfa {
                            key level;

                            leaf value
                       description
                        "Remote LFA alternate.";
                     }
                     enum tunnel {
                                type uint16;
                                units "seconds";
                       description
                                 "This leaf defines the interval of
                                 hello messages.";
                        "Tunnel based alternate
                        (like RSVP-TE or GRE).";
                     }
                            leaf level
                     enum ti-lfa {
                                type level;
                       description
                                    "Level applicability.";
                        "TI LFA alternate.";
                     }
                     enum mrt {
                       description
                                 "This leaf defines the interval of
                                 hello messages.";
                        "MRT alternate.";
                     }
                        list hello-multiplier
                     enum other {
                            key level;
                       description
                        "Unknown alternate type.";
                     }
                   }
                   description
                    "Type of alternate.";
                 }
                 leaf value best {
                   type uint16; boolean;
                   description
                                 "This leaf defines
                    "describes if the number of
                                 hello failed alternate is the best one.";

                 }
                 leaf non-best-reason {
                   type string;
                   description
                    "Information field to be received before
                                 declaring describe why the adjacency down."; alternate
                    is not best.";
                 }
                 leaf level protection-available {
                   type level; bits {
                     bit nodeprotect {
                       position 0;
                       description
                                    "Level applicability.";
                       "Node protection available.";
                     }
                     bit linkprotect {
                       position 1;
                       description
                                 "This leaf defines the number of
                                  hello failed to be received before
                                  declaring
                       "Link protection available.";
                     }
                     bit srlgprotect {
                       position 2;
                       description
                       "SRLG protection available.";
                     }
                     bit downstreamprotect {
                       position 3;
                       description
                       "Downstream protection available.";
                     }
                     bit other {
                       position 4;
                       description
                       "Other protection available.";
                     }
                   }
                   description
                   "Describes protection provided by the adjacency down."; alternate.";
                 }

                        list priority {
                            must 'interface-type = "broadcast"';
                            key level;
                 leaf value alternate-metric1 {
                   type uint8 {
                                    range "0 .. 127";
                                } uint32;
                   description
                                 "This leaf describes the priority of
                    "Metric from PLR to destination
                     through the interface
                                 for DIS election."; alternate path.";
                 }
                 leaf level alternate-metric2 {
                   type level; uint32;
                   description
                                    "Level applicability.";
                    "Metric from PLR to the alternate node";

                 }
                            description
                                 "This
                 leaf describes alternate-metric3 {
                   type uint32;
                   description
                    "Metric from alternate node to the priority destination";
                 }

                 description
                  "Per AF statistics.";
               }
               description
                "List of
                                 the interface
                                 for DIS election."; prefixes that are protected.";
             }

             container nonprotected-routes {
                list metric af-stats {
                 key level; "af prefix";

                 leaf value af {
                   type wide-metric; identityref {
                     base rt:address-family;
                   }
                   description
                                 "Metric value.";
                    "Address-family";
                 }
                 leaf level prefix {
                   type level; string;
                   description
                                    "Level applicability.";
                    "Protected prefix.";
                 }
                 description
                             "Container for interface metric";
                  "Per AF statistics.";
               }
               description
                "List of prefixes that are not protected.";
             }

             list af interfaces {
               key af; interface;
               leaf af interface {
                 type string;
                 description
                                    "Address-family";
                  "This leaf describes the name
                  of the interface.";
               }
                            container bfd {
                                if-feature bfd;

               leaf enabled protection-enabled {
                 type boolean;
                                    default false;
                 description
                  "This leaf enables BFD."; describes if protection
                  is requested for the interface.";
               }

               leaf candidate-disabled {
                 type boolean;
                 description
                                    "The container
                  "This leaf describes
                                     BFD config."; if interface
                  is prevented to be used as backup.";
               }
               description
                             "List of AFs.";
                "Interface fast reroute state.";
             }
             list topologies protection-statistics {
               key name; frr-protection-method;

               leaf name frr-protection-method {
                 type rt:rib-ref; string;
                 description
                                 "Name of RIB.";
                  "Protection method used.";
               }
               list metric af-stats {
                 key level; af;

                 leaf value af {
                   type wide-metric; identityref {
                     base rt:address-family;
                   }
                   description
                                     "Metric value.";
                    "Address-family";
                 }
                 leaf level total-routes {
                   type level;
                                    description
                                        "Level applicability.";
                                } uint32;
                   description
                                 "Container for interface metric";
                    "Total prefixes.";
                 }
                 leaf unprotected-routes {
                   type uint32;
                   description
                             "List
                     "Total of topologies."; prefixes who are
                     not protected.";
                 }
                 leaf protected-routes {
                   type uint32;
                   description
                         "List
                     "Total of ISIS interfaces.";
                    }
                    description
                     "This container defines ISIS interface specific
                     configuration objects."; prefixes who are
                     protected.";

                 }
                 leaf linkprotected-routes {
                   type uint32;
                   description
                    "List
                     "Total of ISIS instances.";
            }
            description
             "This container defines ISIS specific configuration
              objects.";
        } prefixes who are
                     link protected.";
                 }

    augment "/rt:routing-state/rt:routing-instance/"
        +"rt:routing-protocols/rt:routing-protocol" {
        when "rt:type = 'isis:isis'" {
            description
             "This augment is only valid when routing protocol
              instance
                 leaf nodeprotected-routes {
                   type is isis."; uint32;
                   description
                     "Total of prefixes who are
                     node protected.";
                 }
                 description
         "This augments routing protocol instance states with ISIS
          specific parameters.";
        container isis {
            config false;
                  "Per AF statistics.";
               }

               description
                "Global protection statistics.";
             }
             description
              "IPFRR states.";
           }

           container system-counters {
             list level {
               key level;

               leaf level {
                 type level-number;
                 description
                  "This leaf describes the ISIS level.";
               }
               leaf corrupted-lsps {
                 type uint32;
                 description
                  "Number of corrupted in-memory LSPs detected.
                  LSPs received from the wire with a bad
                  checksum are silently dropped and not counted.
                  LSPs received from the wire with parse errors
                  are counted by lsp-errors.";
               }
               leaf authentication-type-fails {
                 type uint32;
                 description
                  "Number of authentication type mismatches.";
               }
               leaf authentication-fails {
                 type uint32;
                 description
                  "Number of authentication key failures.";
               }
               leaf database-overload {
                 type uint32;
                 description
                  "Number of times the database has become
                  overloaded.";
               }
               leaf own-lsp-purge {
                 type uint32;
                 description
                  "Number of times a zero-aged copy of the
                  system's own LSP is received from some
                  other node.";
               }
               leaf manual-address-drop-from-area {
                 type uint32;
                 description
                  "Number of times a manual address
                   has been dropped from the area.";
               }
               leaf max-sequence {
                 type uint32;
                 description
                  "Number of times the system has attempted
                   to exceed the maximum sequence number.";
               }
               leaf sequence-number-skipped {
                 type uint32;
                 description
                  "Number of times a sequence number skip has
                  occured.";
               }
               leaf id-len-mismatch {
                 type uint32;
                 description
                  "Number of times a PDU is received with
                   a different value for ID field length
                          from that of ID field length
                   from that of the receiving system.";
               }
               leaf partition-changes {
                 type uint32;
                 description
                  "Number of partition changes detected.";
               }
               leaf lsp-errors {
                 type uint32;
                 description
                  "Number of LSPs with errors we have
                  received.";
               }
               leaf spf-runs {
                 type uint32;
                 description
                  "Number of times we ran SPF at this level.";
               }
               description
                "List of supported levels.";
             }
             description
              "The container defines a list of counters
               for the IS.";
           }

           container interfaces {
             list interfaces {
               key interface;

               leaf interface {
                 type string;
                 description
                  "This leaf describes the name
                  of the interface.";
               }
               container status {
                 leaf circuit-id {
                   type circuit-id;
                   description
                    "This leaf describes the circuit-id
                    associated with the interface.";
                 }
                 leaf admin-state {
                   type admin-state;
                   description
                   "This leaf describes the admin state
                   of the interface.";
                 }
                 leaf oper-state {
                   type oper-state;
                   description
                   "This leaf describes the operational state
                   of the interface.";
                 }
                 leaf interface-type {
                   type interface-type;
                   description
                   "Type of interface to be used.";
                 }
                 leaf passive {
                   type empty;
                   description
                    "The interface is included in LSP, but
                    does not run ISIS protocol.";
                 }
                 leaf three-way-handshake {
                   type boolean;
                   description
                    "The interface uses 3-way handshake.";
                 }
                 leaf mesh-group-enabled {
                   type mesh-group-state;
                   description
                    "Mesh group status.";
                 }
                 leaf mesh-group {
                   type uint8;
                   description
                    "Mesh group value.";
                 }
                 list level {
                   key level;

                   leaf level {
                     type level;
                     description
                     "Level associated with the interface.";
                   }
                   leaf priority {
                     type uint8;
                     description
                      "Priority for becoming the receiving system."; LAN DIS.";
                   }
                   leaf partition-changes hello-multiplier {
                     type uint32; uint16;
                     description
                         "Number of partition changes detected.";
                      "Hello multiplier.";
                   }
                   leaf lsp-errors hello-interval {
                     type uint32; uint16;
                     description
                         "Number of LSPs with errors we have
                         received.";
                      "Hello interval in msec.";
                   }
                   leaf spf-runs dr-hello-interval {
                     type uint32;
                     description
                         "Number of times we ran SPF at this level.";
                      "Hello interval used by DIS in msec.";
                   }

                   leaf metric {
                     type empty;
                     description
                     "List of supported levels.";
                      "The interface is included in LSP, but
                      does not run ISIS protocol.";
                   }
                   description
                 "The container defines a list of counters
                  for the IS.";
                    "Per level states.";
                 }
            container interface-counters {
                list interface {
                    key interface;

                    leaf interface {
                        type string;

                 description
                         "This leaf describes the name
                         of the interface.";
                  "Provides ISIS interface status parameters.";
               }
               container event-counters {
                 leaf adjacency-changes {
                   type uint32;
                   description
                    "The number of times an adjacency state
                     change has occured on this interface.";
                 }
                 leaf adjacency-number {
                   type uint32;
                   description
                    "The number of adjacencies on this
                     interface.";
                 }
                 leaf init-fails {
                   type uint32;
                   description
                    "The number of times initialization of
                     this interface has failed. This counts
                     events such as PPP NCP failures.
                     Failures to form an adjacency are counted
                     by adjacency-rejects.";
                 }
                 leaf adjacency-rejects {
                   type uint32;
                   description
                    "The number of times an adjacency has been
                     rejected on this interface.";
                 }
                 leaf id-len-mismatch {
                   type uint32;
                   description
                    "The number of times an IS-IS PDU with an ID
                     field length different from that for this
                     system has been received on this interface.";
                 }
                 leaf max-area-addresses-mismatch {
                   type uint32;
                   description
                    "The number of times an IS-IS PDU with
                     according max area address field
                     differs from that for
                     this system has been received on this
                     interface.";
                 }
                 leaf authentication-type-fails {
                   type uint32;
                   description
                    "Number of authentication type mismatches.";
                 }
                 leaf authentication-fails {
                   type uint32;
                   description
                    "Number of authentication key failures.";
                 }
                 leaf lan-dis-changes {
                   type uint32;
                   description
                    "The number of times the DIS has changed
                     on this interface at this level.
                     If the interface type is point to point,
                     the count is zero.";
                 }
                 description
                     "List of interfaces.";
                }
                description
                 "The container defines a list of counters
                  for interfaces.";
                  "Provides protocol event counters.";
               }
               container packet-counters {
                 list level {
                   key level;

                   leaf level {
                     type level-number;
                     description
                      "This leaf describes the ISIS level.";
                   }

                   container iih {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of IIH PDUs received/sent.";
                   }
                   container ish {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of ISH PDUs received/sent.";
                   }
                   container esh {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of ESH PDUs received/sent.";
                   }
                   container lsp {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of LSP PDUs received/sent.";
                   }
                   container psnp {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of PSNP PDUs received/sent.";
                   }
                   container csnp {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of CSNP PDUs received/sent.";
                   }
                   container unknown {
                     leaf in {
                       type uint32;
                       description
                        "Received PDUs.";
                     }
                     leaf out {
                       type uint32;
                       description
                        "Sent PDUs.";
                     }
                     description
                      "The number of unknown PDUs received/sent.";
                   }
                   description
                    "List of supported levels.";
                }
                description
                 "The container defines a list of PDU counters.";
            }
            container interfaces {
                list interfaces {
                    key interface;

                    leaf interface {
                        type string;
                        description
                         "This leaf describes the name
                         of the interface.";
                    }
                    leaf circuit-id {
                        type circuit-id;
                        description
                         "This leaf describes the circuit-id
                         associated with the interface.";
                    }
                    leaf admin-state {
                        type admin-state;
                        description
                        "This leaf describes the admin state
                        of the interface.";
                    }
                    leaf oper-state {
                        type oper-state;
                        description
                        "This leaf describes the operational state
                        of the interface.";
                    }
                    leaf interface-type {
                        type interface-type;
                        description
                        "Type of interface to be used.";
                    }
                    leaf level {
                        type level;
                        description
                        "Level associated with the interface.";
                    }
                    leaf passive {
                        type empty;
                        description
                         "The interface is included in LSP, but
                         does not run ISIS protocol."; of supported levels.";
                 }
                    leaf three-way-handshake {
                        type empty;
                 description
                         "The interface uses 3-way handshake.";
                  "Provides packet counters per level.";
               }
               description
                "List of interfaces.";
             }
             description
              "The container defines operational parameters
               of interfaces.";
           }
           container adjacencies {
             list adjacency {
               leaf interface {
                 type string;
                 description
                  "This leaf describes the name
                  of the interface.";
               }
               leaf level neighbor-systype {
                 type level;
                 description
                            "This leaf describes the associated
                            ISIS level
                  "Type of the interface.
                            "; neighboring system";

               }
               leaf neighbor-sysid {
                 type system-id;
                 description
                  "The system-id of the neighbor";

               }
               leaf neighbor-extended-circuit-id {
                 type extended-circuit-id;
                 description
                  "Circuit ID of the neighbor";
               }
               leaf neighbor-snpa {
                 type snpa;
                 description
                  "SNPA of the neighbor";
               }
               leaf neighbor-level usage {
                 type level;
                 description
                        "The type of
                 "How is the neighboring system."; adjacency used ?
                 On a p2p link this might be level 1 and 2,
                 but on a LAN, the usage will be level 1
                 between peers at L1 or level 2 between
                 peers at L2.";
               }
               leaf hold-timer {
                 type uint16;
                 description
                  "The holding time in seconds for this
                   adjacency. This value is based on
                   received hello PDUs and the elapsed
                   time since receipt.";
               }
               leaf neighbor-priority {
                 type uint8 {
                   range "0 .. 127";
                 }
                 description
                  "Priority of the neighboring IS for becoming
                   the DIS.";
               }
               leaf lastuptime {
                 type yang:timestamp;
                 description
                  "When the adjacency most recently entered
                   state 'up', measured in hundredths of a
                   second since the last reinitialization of
                   the network management subsystem.
                   The value is 0 if the adjacency has never
                   been in state 'up'.";

               }
               leaf state {
                 type enumeration {
                   enum "Up" {
                     description
                      "This state describes that
                       adjacency is established.";
                   }
                   enum "Down" {
                     description
                      "This state describes that
                       adjacency is NOT established.";
                   }
                   enum "Init" {
                     description
                      "This state describes that
                       adjacency is establishing.";
                   }
                   enum "Failed" {
                     description
                      "This state describes that
                       adjacency is failed.";
                   }
                 }
                 description
                  "This leaf describes the state of the
                  interface.";
               }
               list adjacency-sid {
                 if-feature segment-routing;
                 key value;
                 leaf af {
                   type identityref {
                     base rt:address-family;
                   }
                   description
                    "Address-family associated with the
                    segment ID";
                 }
                 leaf value {
                   type uint32;
                   description
                    "Value of the Adj-SID.";
                 }
                 leaf weight {
                   type uint8;
                   description
                    "Weight associated with
                    the adjacency SID.";
                 }
                 leaf protection-requested {
                   type boolean;
                   description
                    "Describe if the adjacency SID
                    must be protected.";
                 }
                 description
                  "List of adjacency Segment IDs.";
               }
               description
                "List of operational adjacencies.";
             }
             description
              "This container lists the adjacencies of
              the local node.";
           }
           container spf-log {
             list event {
               key id;

               leaf id {
                 type uint32;
                 description
                  "This leaf defines the event identifier.
                   This is a purely internal value.";
               }
               leaf spf-type {
                 type enumeration {
                   enum full {
                     description
                      "Computation done is a Full SPF.";
                   }
                   enum incremental {
                     description
                      "Computation done is an
                       incremental SPF.";
                   }
                   enum route-only {
                     description
                      "Computation done is a
                       reachability computation
                       only.";
                   }
                 }
                 description
                  "This leaf describes the type of computation
                  used.";
               }
               leaf level {
                 type level-number;
                 description
                  "This leaf describes the level affected by the
                  the computation.";
               }
               leaf spf-delay {
                 type uint32;
                 units "milliseconds";
                 description
                  "This leaf describes the SPF delay that
                  was used for this event.";
               }
               leaf schedule-timestamp {
                 type yang:timestamp;
                 description
                  "This leaf describes the timestamp
                   when the computation was scheduled.";
               }
               leaf start-timestamp {
                 type yang:timestamp;
                 description
                  "This leaf describes the timestamp
                   when the computation was started.";
               }
               leaf end-timestamp {
                 type yang:timestamp;
                 description
                  "This leaf describes the timestamp
                   when the computation was ended.";
               }
               list trigger-lsp {
                 key "lsp";
                 leaf lsp {
                   type lsp-id;
                   description
                    "This leaf describes the LSPID
                     of the LSP.";
                 }
                 leaf sequence {
                   type uint32;
                   description
                    "This leaf describes the sequence
                     number of the LSP.";
                 }
                 description
                  "This leaf describes list of LSPs
                   that triggered the computation.";
               }
               description
                "List of computation events.";
             }

             description
              "This container lists the SPF computation events.";
           }
           container lsp-log {
             list event {
               key id;

               leaf id {
                 type uint32;
                 description
                  "This leaf defines the event identifier.

                   This is a purely internal value.";
               }
               leaf level {
                 type level-number;
                 description
                  "This leaf describes the level affected by the
                  the computation.";
               }
               container lsp {
                 leaf lsp {

                   type lsp-id;
                   description
                    "This leaf describes the LSPID
                     of the LSP.";
                 }
                 leaf sequence {
                   type uint32;
                   description
                    "This leaf describes the sequence
                     number of the LSP.";
                 }
                 description
                  "This container describes the received LSP
                  , in case of local LSP update the local
                  LSP ID is referenced.";
               }

               leaf received-timestamp {
                 type yang:timestamp;

                 description
                  "This leaf describes the timestamp
                  when the LSP was received. In case of
                  local LSP update, the timestamp refers
                  to the local LSP update time.";
               }

               leaf change {
                 type bits {
                   bit refresh {
                     position 0;
                     description
                      "Refresh LSP, nothing has changed.";
                   }
                   bit link-down {
                     position 1;
                     description
                      "One or more links are down.";
                   }
                   bit link-up {
                     position 2;
                     description
                      "One or more links are up.";
                   }
                   bit link-metric-change {
                     position 3;
                     description
                      "One or more links experienced
                      a metric change.";
                   }
                   bit link-other-change {
                     position 4;
                     description
                      "One or more links experienced
                      a change that does not affect state
                      or metric.";
                   }
                   bit prefix-down {
                     position 5;
                     description
                      "One or more links are down.";
                   }
                   bit prefix-up {
                     position 6;
                     description
                      "One or more prefixes are up.";
                   }
                   bit prefix-metric-change {
                     position 7;
                     description
                      "One or more prefixes experienced
                      a metric change.";
                   }
                   bit prefix-other-change {
                     position 8;
                     description
                      "One or more prefixes experienced
                      a change that does not affect state
                      or metric.";
                   }
                   bit other-change {
                     position 9;
                     description
                      "One or more component changed that
                      is not a prefix or link.";

                   }
                 }
                 description
                  "This leaf describes the type of change
                  in the LSP.";
               }

               description
                "List of LSP events.";
             }

             description
              "This container lists the LSP reception events.
              Local LSP modification are also contained in the
              list.";
           }
           container database {
             list level-db {
               key level;

               leaf level {
                 type level-number;
                 description
                  "Current level number";
               }
               list lsp {
                 key lsp-id;

                 uses database;
                 description
                  "List of LSPs in LSDB.";
               }

               description
                "This container describes the list of LSPs
                in the level x database.";
             }

             description
              "This container describes ISIS Link State
               databases.";
           }
           container hostnames {

             list hostname {
               key system-id;
               leaf system-id {
                 type system-id;
                 description
                  "This leaf describes the system-id
                  associated with the hostname.";
               }
               leaf hostname {

                 type string;
                 description
                  "This leaf describes the hostname
                   associated with the system ID.";
               }
               description
                "List of system-id/hostname associations";
             }

             description
              "This container describes the list
              of binding between system-id and
              hostnames.";
           }

           description
            "List of ISIS instances.";
         }
         description
            "This container defines various ISIS states objects.";
       }
     }

     /* RPC methods */

     rpc clear-adjacency {
       description
        "This RPC request clears a particular
         set of ISIS adjacencies. If the operation
         fails for ISIS internal reason, then
         error-tag and error-app-tag should be set
         to a meaningful value.";
       input {
                       leaf routing-instance-name {
           type rt:routing-instance-state-ref;
           mandatory "true";
           description
            "Name of the routing instance whose ISIS
             information is being queried.

             If the routing instance with name equal to the
             value of this parameter doesn't exist, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag 'routing-instance-not-found'.";

         }
         leaf routing-protocol-instance-name {
           type instance-state-ref;
           mandatory "true";
           description
            "Name of the ISIS protocol instance whose ISIS
             information is being queried.

             If the ISIS instance with name equal to the
             value of this parameter doesn't exist, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag
             'routing-protocol-instance-not-found'.";
         }
         leaf level {
           type level;
           description
            "ISIS level of the adjacency to be cleared.
            If ISIS level is level-1-2, both level 1 and level 2
            adjacencies would be cleared.

            If the value provided is different from the one
            authorized in the enum type, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag
             'bad-isis-level'.
            ";
         }
         leaf interface {
           type string;
           description
            "Name of the ISIS interface.

             If the ISIS interface with name equal to the
             value of this parameter doesn't exist, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag
             'isis-interface-not-found'.";
         }
       }
     }

     rpc clear-database {
       description
        "This RPC request clears a particular
         ISIS database. If the operation
         fails for ISIS internal reason, then
         error-tag and error-app-tag should be set
         to a meaningful value.";
       input {
         leaf routing-instance-name {
           type rt:routing-instance-state-ref;
           mandatory "true";
           description
            "Name of the routing instance whose ISIS
             information is being queried.

             If the routing instance with name equal to the
             value of this parameter doesn't exist, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag 'routing-instance-not-found'.";

         }
         leaf routing-protocol-instance-name {
           type instance-state-ref;
           mandatory "true";
           description
            "Name of the ISIS protocol instance whose ISIS
             information is being queried.

             If the ISIS instance with name equal to the
             value of this parameter doesn't exist, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag
             'routing-protocol-instance-not-found'.";
         }
         leaf level {
           type level;
           description
            "ISIS level of the adjacency to be cleared.
            If ISIS level is level-1-2, both level 1 and level 2
            adjacencies would be cleared.

            If the value provided is different from the one
            authorized in the enum type, then this
             operation SHALL fail with error-tag 'data-missing'
             and error-app-tag
             'bad-isis-level'.
            ";
         }
       }

     }

     /* Notifications */

     notification database-overload {
       uses notification-instance-hdr;

       leaf overload {
         type enumeration {
           enum "off" {
             description
              "The system has left overload condition.";
           }
           enum "on" {
             description
              "The system is in overload condition.";
           }

         }
         description
            "Describes the new overload state of the instance.";
       }
       description
         "This notification is sent when an ISIS instance
          overload condition changes.";
     }

     notification lsp-too-large {
       uses notification-instance-hdr;
       uses notification-interface-hdr;

       leaf pdu-size {
         type uint32;
         description
          "Size of the PDU";
       }
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       description
         "This notification is sent when we attempt
          to propagate an LSP that is larger than the
          dataLinkBlockSize for the circuit.
          The notification generation must be throttled
          with at least a 5 second gap.
          ";
     }

     notification corrupted-lsp-detected {
       uses notification-instance-hdr;
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       description
         "This notification is sent when we find
          that an LSP that was stored in memory has
          become corrupted.
          ";
     }

     notification attempt-to-exceed-max-sequence {
       uses notification-instance-hdr;
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       description
         "This notification is sent when the system
         wraps the 32-bit sequence counter of an LSP.
          ";
     }

     notification id-len-mismatch {
       uses notification-instance-hdr;
       uses notification-interface-hdr;

       leaf pdu-field-len {
         type uint8;
         description
          "Size of the ID length in the received PDU";
       }
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when we receive a PDU
         with a different value for the System ID length.

         The notification generation must be throttled
         with at least a 5 second gap.
          ";
     }

     notification max-area-addresses-mismatch {
       uses notification-instance-hdr;
       uses notification-interface-hdr;

       leaf max-area-addresses {
         type uint8;
         description
          "Received number of supported areas";
       }
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when we receive a PDU
         with a different value for the Maximum Area Addresses.
         The notification generation must be throttled
         with at least a 5 second gap.
          ";
     }

     notification own-lsp-purge {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       description
         "This notification is sent when the system
         receives a PDU with its own system ID and zero age.
          ";
     }

     notification sequence-number-skipped {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";

       }
       description
         "This notification is sent when the system
         receives a PDU with its own system ID and
         different contents. The system has to reissue
         the LSP with a higher sequence number.
          ";
     }

     notification authentication-type-failure {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when the system
         receives a PDU with the wrong authentication type
         field.
         The notification generation must be throttled with
         at least a 5 second gap.
          ";
     }

     notification authentication-failure {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when the system
         receives a PDU with the wrong authentication
         information.
         The notification generation must be throttled with
         at least a 5 second gap.
          ";
     }

     notification version-skew {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf protocol-version {
         type uint8;
         description
          "Protocol version received in the PDU.";
       }
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when the system
         receives a PDU with a different protocol version
         number.
         The notification generation must be throttled with at least
          a 5 second gap.
          ";
     }

     notification area-mismatch {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       description
         "This notification is sent when the system
         receives a Hello PDU from an IS that does
         not share any area address.
         The notification generation must be throttled with at least
          a 5 second gap.
          ";
     }

     notification rejected-adjacency {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       leaf reason {
         type string;
         description
          "The system may provide a reason to reject the
           adjacency. If the reason is not available,
           the system use an empty string.";

       }
       description
         "This notification is sent when the system
         receives a Hello PDU from an IS but does not
         establish an adjacency for some reason.
         The notification generation must be throttled with at least
          a 5 second gap.
          ";
     }

     notification protocols-supported-mismatch {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       leaf-list protocols {
         type uint8;
         description
          "The list of protocols supported by the
           remote system.";
       }
       description
         "This notification is sent when the system
         receives a non pseudonode LSP that has no matching
         protocol supported.
         The notification generation must be throttled with at least
          a 5 second gap.
          ";
     }

     notification lsp-error-detected {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       leaf raw-pdu {
         type binary;
         description
          "Received raw PDU.";
       }
       leaf error-offset {
         type uint32;
         description
          "If the problem is a malformed TLV,
          the error-offset points to the start of the TLV.
          If the problem is with the LSP header,
          the error-offset points to the suspicious byte";
       }
       leaf tlv-type {
         type uint8;
         description
          "if the problem is a malformed TLV, the tlv-type is set
          to the type value of the suspicious TLV.
          Otherwise this leaf is not present.";
       }
       description
         "This notification is sent when the system
         receives a  LSP with a parse error.
         The notification generation must be throttled with at least
          a 5 second gap.
          ";
     }

     notification adjacency-change {
       uses notification-instance-hdr;
       uses notification-interface-hdr;
       leaf neighbor {
         type string;
         description
          "Describes the name of the neighbor. If the
          name of the neighbor is not available, the
          field would be empty.";
       }
       leaf neighbor-system-id {
         type system-id;
         description
          "Describes the system-id of the neighbor.";
       }
       leaf level {
         type level;
         description
          "Describes the ISIS level of the adjacency.";
       }
       leaf state {
         type enumeration {
           enum "Up" {
             description
              "This state describes that
               adjacency is established.";

           }
           enum "Down" {
             description
              "This state describes that
               adjacency is no more established.";
           }
         }
         description
          "This leaf describes the new state of the
           ISIS adjacency.";
       }
       leaf reason {
         type string;
         description
          "If the adjacency is going to DOWN,
          this leaf provides a reason for the adjacency
          going down. The reason is provided as a text.
          If the adjacency is going to UP, no reason is
          provided.";
       }
       description
         "This notification is sent when an ISIS adjacency
          moves to Up state or to Down state.";
     }

     notification lsp-received {
       uses notification-instance-hdr;
       uses notification-interface-hdr;

       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       leaf sequence {
         type uint32;
         description
          "Sequence number of the received LSP.";
       }
       leaf received-timestamp {
         type yang:timestamp;

         description
          "This leaf describes the timestamp
          when the LSP was received. ";
       }
       leaf neighbor-system-id {
         type system-id;
         description
          "Describes the system-id of the neighbor
          that sent the LSP.";
       }
       description
         "This notification is sent when a LSP
         is received.
         The notification generation must be throttled with at least
          a 5 second gap. ";
     }

     notification lsp-generation {
       uses notification-instance-hdr;

       leaf lsp-id {
         type lsp-id;
         description
          "LSP ID.";
       }
       leaf sequence {
         type uint32;
         description
          "Sequence number of the received LSP.";
       }
       leaf send-timestamp {
         type yang:timestamp;

         description
          "This leaf describes the timestamp
          when our LSP was regenerated. ";
       }
       description
         "This notification is sent when a LSP
         is regenerated.
         The notification generation must be throttled with at least
          a 5 second gap. ";
     }

   }

   <CODE ENDS>

7.  Security Considerations

   Configuration and state data defined in this document are designed to
   be accessed via the NETCONF protocol [RFC6241].

   As ISIS is an IGP protocol (critical piece of the network), ensuring
   stability and security of the protocol is mandatory for the network
   service.

   Authors recommends to implement NETCONF access control model
   ([RFC6536]) to restrict access to all or part of the configuration to
   specific users.  Access control to RPCs is also critical as RPC
   permits to clear protocol datastructures that would definitively
   impact the network service.  This kind of RPC needs only to be used
   in specific cases by well-known experienced users.

   Authors consider that all the configuration is considered as
   sensitive/vulnerable as well as RPCs.  But security teams can decide
   to open some part of the configuration to less experienced users
   depending on the internal organization, for example:

   o  User FullWrite: would access to the whole data model.  This kind
      of profile may be restricted to few experienced people.

   o  User PartialWrite: would only access to configuration part within
      /isis/interfaces/interface.  So this kind of profile is restricted
      to creation/modification/deletion of interfaces.  This profile
      does not have access to RPC.

   o  User Read: would only access to state part /isis-state.

   Unauthorized access to configuration or RPC may cause high damages to
   the network service.

   The /isis-state/database may contain authentication information.  As
   presented in the description of the /isis-state/database/level-
   1/lsp/authentication/authentication-key, the authentication MUST
   never be presented in plaintext format for security reason.  Authors
   recommends the usage of MD5 to present the authentication-key.

   Some authentication-key may also be present in the /isis
   configuration.  When configuring ISIS using the NETCONF protocol,
   authors recommends the usage of secure transport of NETCONF using SSH
   ([RFC6242]).

8.  Contributors

   Authors would like to thank Kiran Agrahara Sreenivasa, Dean
   Bogdanovic, Yingzhen Qu, Yi Yang for their major contributions to the
   draft.

9.  Acknowledgements

   TBD.

10.  IANA Considerations

   TBD.

11.  Normative References

   [I-D.ietf-netmod-routing-cfg]
              Lhotka, L., "A YANG Data Model for Routing Management",
              draft-ietf-netmod-routing-cfg-15
              draft-ietf-netmod-routing-cfg-16 (work in progress), May
              October 2014.

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

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

   [RFC6241]  Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
              Bierman, "Network Configuration Protocol (NETCONF)", RFC
              6241, June 2011.

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

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

Appendix A.  Example: NETCONF <get> Reply

   This section gives an example of a reply to the NETCONF <get> request
   for a device that implements the data model defined in this document.
   The example is written in XML.

<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
    <routing-instance>
      <name>SLI</name>
      <router-id>1.1.1.1</router-id>
      <description/>
      <default-ribs>
        <default-rib>
          <address-family>ipv4-unicast</address-family>
          <rib-name>default</rib-name>
        </default-rib>
      </default-ribs>
      <interfaces>
        <interface>
          <name>Loopback0</name>
        </interface>
                <interface>
          <name>Eth1</name>
        </interface>
      </interfaces>
      <routing-protocols>
        <routing-protocol>
          <name>ISIS</name>
          <description/>
          <type>isis:isis</type>
          <connected-ribs>
            <connected-rib>
              <rib-name>default</rib-name>
              <import-filter/>
              <export-filter/>
            </connected-rib>
          </connected-ribs>
          <isis xmlns="urn:ietf:params:xml:ns:yang:ietf-isis">
            <instance>
              <routing-instance>SLI</routing-instance>
                          <level-type>level-2</level-type>
              <system-id>87FC.FCDF.4432</system-id>
              <area-address>49.0001</area-address>
              <mpls-te>
                <ipv4-router-id>1.1.1.1</ipv4-router-id>
              </mpls-te>
              <lsp-lifetime>65535</lsp-lifetime>
              <lsp-refresh>65000</lsp-refresh>
              <authentication>
                            <key>ThisIsThePassword</key>
                <type>plain-text</type>
                                <level>level-2</level>
              </authentication>
              <metric-type>
                <value>wide</value>
              </metric-type>
              <default-metric>
                <value>111111</value>
              </default-metric>
              <af>
                <af>ipv4-unicast</af>
                <enabled>true</enabled>
              </af>
              <interfaces>
                <interface>
                  <name>Loopback0</name>
                  <tag>200</tag>
                  <metric>
                    <value>0</value>
                  </metric>
                                  <passive>true</passive>
                </interface>
                                <interface>
                  <name>Eth1</name>
                                  <level-type>level-2</level-type>
                                  <interface-type>point-to-point</interface-type>
                  <metric>
                    <value>167890</value>
                  </metric>

                </interface>
              </interfaces>
            </instance>
          </isis>
        </routing-protocol>
      </routing-protocols>
    </routing-instance>
    <ribs>
      <rib>
        <name>default</name>
        <address-family>ipv4-unicast</address-family>
        <description/>
        <recipient-ribs>
          <recipient-rib>
            <rib-name/>
            <filter/>
          </recipient-rib>
        </recipient-ribs>
      </rib>
    </ribs>
    <route-filters>
      <route-filter>
        <name/>
        <description/>
        <type/>
      </route-filter>
    </route-filters>
  </routing>
  <interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
    <interface>
      <name>Loopback0</name>
      <description/>
      <type/>
      <link-up-down-trap-enable/>
      <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
        <mtu/>
        <address>
          <ip>1.1.1.1</ip>
          <prefix-length>32</prefix-length>
        </address>
      </ipv4>

    </interface>
        <interface>
      <name>Eth1</name>
      <description/>
      <type/>
      <link-up-down-trap-enable/>
      <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
        <mtu/>
        <address>
          <ip>10.0.0.1</ip>
          <prefix-length>30</prefix-length>
        </address>
      </ipv4>

    </interface>
  </interfaces>
</data>

Authors' Addresses

   Stephane Litkowski
   Orange

   Email: stephane.litkowski@orange.com

   Derek Yeung
   Cisco Systems

   Email: myeung@cisco.com
   Acee Lindem
   Cisco Systems

   Email: acee@cisco.com

   Jeffrey Zhang
   Juniper Networks

   Email: zzhang@juniper.net

   Ladislav Lhotka

   Email: lhotka@nic.cz