ISIS Working Group S. Litkowski
Internet-Draft Orange
Intended status: Standards Track D. Yeung
Expires: April 27, 2015 A. Lindem
Cisco Systems
J. Zhang
Juniper Networks
L. Lhotka
October 24, 2014

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

Abstract

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

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, 2015.

Copyright Notice

Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

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


Table of Contents

1. Introduction

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:

2. Design of the Data Model

The ISIS YANG module is divided in two main containers "isis" 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
augment /rt:active-route/rt:output/rt:route:
   +--ro metric?       uint32
   +--ro tag*          uint64
   +--ro route-type?   enumeration
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
         |     ...
         +--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 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]
      |        ...
      +--ro interface-counters
      |  +--ro interface* [interface]
      |        ...
      +--ro packet-counters
      |  +--ro level* [level]
      |        ...
      +--ro interfaces
      |  +--ro interfaces* [interface]
      |        ...
      +--ro adjacencies
      |  +--ro adjacency*
      |        ...
      +--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                   
   |  +--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 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:

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-te
         |  +--rw ipv4-router-id?   inet:ipv4-address {ipv4-router-id}?
         |  +--rw ipv6-router-id?   inet:ipv6-address {ipv6-router-id}?
         +--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 enabled?   boolean
         +--rw authentication* [level]
         |  +--rw key?     string
         |  +--rw type?    authentication-type
         |  +--rw level    level
         +--rw metric-type* [level]
         |  +--rw value?   enumeration
         |  +--rw level    level
         +--rw preference* [level]
         |  +--rw (granularity)?
         |  |  +--:(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 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 list is used to enable support of MT extensions for specific address families.

Each topology should refer to an existing RIB.

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 to check if the interface exists or not. Using a string permits to support some specific implementations that use the "interface all" stanza to apply a configuration to all interfaces.

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
               +--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
               |  +--rw key?     string
               |  +--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
               |  +--rw bfd {bfd}?
               |        ...
               +--rw topologies* [name]
                  +--rw name      rt:rib-ref
                  +--rw metric* [level]
                        ...

2.5. Operational State

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

augment /rt:routing-state/rt:routing-instance/rt:routing-protocols/rt:routing-protocol:
   +--ro isis
      +--ro system-counters
      |  +--ro level* [level]
      |     +--ro level                            level-number
      |     +--ro corrupted-lsps?                  uint32
      |     +--ro authentication-type-fails?       uint32
      |     +--ro authentication-fails?            uint32
      |     +--ro database-overload?               uint32
      |     +--ro own-lsp-purge?                   uint32
      |     +--ro manual-address-drop-from-area?   uint32
      |     +--ro max-sequence?                    uint32
      |     +--ro sequence-number-skipped?         uint32
      |     +--ro id-len-mismatch?                 uint32
      |     +--ro partition-changes?               uint32
      |     +--ro lsp-errors?                      uint32
      |     +--ro spf-runs?                        uint32
      +--ro interface-counters
      |  +--ro interface* [interface]
      |     +--ro interface                      string
      |     +--ro adjacency-changes?             uint32
      |     +--ro adjacency-number?              uint32
      |     +--ro init-fails?                    uint32
      |     +--ro adjacency-rejects?             uint32
      |     +--ro 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 interfaces
      |  +--ro interfaces* [interface]
      |     +--ro interface              string
      |     +--ro circuit-id?            circuit-id
      |     +--ro admin-state?           admin-state
      |     +--ro oper-state?            oper-state
      |     +--ro interface-type?        interface-type
      |     +--ro level?                 level
      |     +--ro passive?               empty
      |     +--ro three-way-handshake?   empty
      +--ro adjacencies
      |  +--ro adjacency*
      |     +--ro interface?                      string
      |     +--ro level?                          level
      |     +--ro neighbor-sysid?                 system-id
      |     +--ro neighbor-extended-circuit-id?   extended-circuit-id
      |     +--ro neighbor-snpa?                  snpa
      |     +--ro neighbor-level?                 level
      |     +--ro hold-timer?                     uint16
      |     +--ro neighbor-priority?              uint8
      |     +--ro lastuptime?                     yang:timestamp
      |     +--ro state?                          enumeration
      +--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 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 authentication
      |        |  +--ro authentication-type?   authentication-type
      |        |  +--ro authentication-key?    string
      |        +--ro extended-is-neighbor
      |        |  +--ro neighbor* [neighbor-id]
      |        |        ...
      |        +--ro ipv4-internal-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro protocol-supported*              uint8
      |        +--ro ipv4-external-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro ipv4-addresses*                  inet:ipv4-address
      |        +--ro ipv4-te-routerid?                inet:ipv4-address
      |        +--ro extended-ipv4-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro dynamic-hostname?                string
      |        +--ro ipv6-te-routerid?                inet:ipv6-address
      |        +--ro mt-is-neighbor
      |        |  +--ro neighbor* [neighbor-id]
      |        |        ...
      |        +--ro mt-entries
      |        |  +--ro topology* [MT-ID]
      |        |        ...
      |        +--ro ipv6-addresses*                  inet:ipv6-address
      |        +--ro mt-extended-ipv4-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro mt-ipv6-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro ipv6-reachability
      |        |  +--ro prefixes* [ip-prefix]
      |        |        ...
      |        +--ro router-capabilities
      |           +--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:

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 :

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 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" 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@2014-10-24.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;
	}
	
	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 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 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 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 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.";
	}
	
	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 {
		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 {
		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 of an object.";
		
	}
	
	typedef level-number {
		type uint8 {
			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 {
			pattern '[0-9A-Fa-f]{2}\.([0-9A-Fa-f]{4}\.){0,3}';
		}
		description 
		 "This type defines the area address.";
	}
	
	typedef snpa {
		type string {
			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 {
			range "0 .. 16777215";
		}
		description
		 "This type defines wide style format
		  of ISIS metric.";
	}
	
	typedef std-metric {
		type uint8 {
			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 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 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 of the interface.";
		}
		leaf extended-circuit-id {
			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 {
				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.";
		}
	}
	
	augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" {
		when "rt:source-protocol = 'isis:isis'" {
			description "ISIS-specific route attributes.";
		}
		uses route-content;
		description
		 "This augments route object in RIB with ISIS-specific
		  attributes.";
	  }
	
	augment "/rt:active-route/rt:output/rt:route"
	   {
		uses route-content;
		description "ISIS-specific route attributes.";
	  }
	
	
	grouping prefix-ipv4-std {
		description
		 "This group defines attributes of an 
		  IPv4 standard prefix.";
		leaf up-down {
			type boolean;
			description 
			 "This leaf expresses the value of up/down bit.";
		}
		leaf i-e {
			type boolean;
			description 
			 "This leaf expresses the value of I/E bit.";
		}
		leaf ip-prefix {
			type inet:ipv4-address;
			description 
			 "This leaf describes the IPv4 prefix";
		}
		leaf prefix-len {
			type uint8;
			description
			 "This leaf describes the IPv4 prefix len in bits";
		}
		leaf default-metric {
			type std-metric;
			description
			 "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";
			}
			leaf supported {
				type boolean;
				default "false";
				description
				 "This leaf describes if the metric is supported.";
			}
			
			description
			 "This container defines the ISIS delay metric.";
		}
		container expense-metric {
			leaf metric {
				type std-metric;
				description
				 "This leaf describes the ISIS expense metric value";
			}
			leaf supported {
				type boolean;
				default "false";
				description
				 "This leaf describes if the metric is supported.";
			}
			description
			 "This container defines the ISIS expense metric.";
		}
		container error-metric {
			leaf metric {
				type std-metric;
				description
				 "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 error metric.";
		}
	}
	
	grouping prefix-ipv4-extended {
		description
		 "This group defines attributes of an 
		  IPv4 extended prefix.";
		leaf up-down {
			type boolean;
			description 
			 "This leaf expresses the value of up/down bit.";
		}
		leaf ip-prefix {
			type inet:ipv4-address;
			description 
			 "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 metric value";
		}
		leaf-list tag {
			type uint32;
			description
			 "This leaf describes a list of tags associated with
			 the prefix.";
		}
		leaf-list tag64 {
			type uint64;
			description
			 "This leaf describes a list of 64-bit tags associated with
			 the prefix.";
		}
	}
	
	grouping prefix-ipv6-extended {
		description
		 "This group defines attributes of an 
		  IPv6 prefix.";
		leaf up-down {
			type boolean;
			description 
			 "This leaf expresses the value of up/down bit.";
		}
		leaf ip-prefix {
			type inet:ipv6-address;
			description 
			 "This leaf describes the IPv6 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 metric value";
		}
		leaf-list tag {
			type uint32;
			description
			 "This leaf describes a list of tags associated with
			 the prefix.";
		}
		leaf-list tag64 {
			type uint64;
			description
			 "This leaf describes a list of 64-bit tags associated with
			 the prefix.";
		}
	}
	
	grouping neighbor-extended {
		description
		 "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.";
		}
		leaf metric {
			type wide-metric;
			description
			 "This leaf describes the ISIS metric value";
		}
	}
	
	grouping neighbor {
		description
		 "This group defines attributes of an 
		  ISIS standard neighbor.";
		leaf neighbor-id {
			type system-id;
			description
			 "This leaf describes the system-id of the neighbor.";
		}
		leaf i-e {
			type boolean;
			description 
			 "This leaf expresses the value of I/E bit.";
		}
		leaf default-metric {
			type std-metric;
			description
			 "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";
			}
			leaf supported {
				type boolean;
				default "false";
				description
				 "This leaf describes if the metric is supported.";
			}
			description
			 "This container defines the ISIS delay metric.";
		}
		container expense-metric {
			leaf metric {
				type std-metric;
				description
				 "This leaf describes the ISIS delay expense value";
			}
			leaf supported {
				type boolean;
				default "false";
				description
				 "This leaf describes if the metric is supported.";
			}
			description
			 "This container defines the ISIS expense metric.";
		}
		container error-metric {
			leaf metric {
				type std-metric;
				description
				 "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 error metric.";
		}
	}
	
	grouping database {
		description
		 "This group defines attributes of an 
		  ISIS database (Link State DB).";
		leaf lsp-id {
			type lsp-id;
			description
			 "This leaf describes the LSP ID of the LSP.";
		}
		leaf checksum {
			type uint16;
			description
			 "This leaf describes the checksum of the LSP.";
		}
		leaf remaining-lifetime {
			type uint16;
			units "seconds";
			description
			 "This leaf describes the remaining lifetime
			  in seconds before the LSP expiration.";
		}
		leaf sequence {
			type uint32;
			description
			 "This leaf describes the sequence number of the LSP.";
		}
		leaf attributes {
			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 {
					description
					 "If set, the originator is attached to
					  another area using the referred metric.";
				}
				bit ATTACHED-DEFAULT {
					description
					 "If set, the originator is attached to
					  another area using the referred metric.";
				}
				bit OVERLOAD {
					description
					 "If set, the originator is overloaded,
					  and must be avoided in path calculation.";
				}
			}
			description
			 "This leaf describes attributes of the LSP.";
		}
		
		container is-neighbor {
			list neighbor {
				key "neighbor-id";
				uses neighbor;	
				description
				 "List of neighbors.";
			}
			description 
			 "This leaf describes list of ISIS neighbors.
			 ISIS reference is TLV 2.";
		}
		
		container authentication {
			leaf authentication-type {
				type authentication-type;
				description
				 "This leaf describes the authentication type
				  to be used.";
			}
			leaf authentication-key {
				type 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 container describes authentication 
			information of the node. ISIS reference is TLV 10.";
		}
		
		container extended-is-neighbor {
			list neighbor {
				key "neighbor-id";
				uses neighbor-extended;
				description
				 "List of neighbors.";
			}
			description 
			 "This container describes list of ISIS extended 
			 neighbors.
			 ISIS reference is TLV 22.";
		}
		
		container ipv4-internal-reachability {
			list prefixes {
				key "ip-prefix";
				uses prefix-ipv4-std;
				description
				 "List of prefixes.";
			}
			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 of 
			 supported protocols.
			 ISIS reference is TLV 129.";
		}
		
		container ipv4-external-reachability {
			list prefixes {
				key "ip-prefix";
				uses prefix-ipv4-std;
				description
				 "List of prefixes.";
			}
			description 
			 "This container describes list of IPv4 external
			 reachability information.
			 ISIS reference is TLV 130.";
		}
		
		leaf-list ipv4-addresses {
			type inet:ipv4-address;
			description 
				"This leaf describes the IPv4 addresses of the node.
				ISIS reference is TLV 132.";
		}
		
		leaf ipv4-te-routerid {
			
			type inet:ipv4-address;
			description 
				"This leaf describes the IPv4 Traffic Engineering 
				router ID of the node.
				ISIS reference is TLV 134.";
		}
		
		container extended-ipv4-reachability {
			
			list prefixes {
				key "ip-prefix";
				uses prefix-ipv4-extended;
				description
				 "List of prefixes.";
			}
			description 
			 "This container describes list of IPv4 extended
			 reachability information.
			 ISIS reference is TLV 135.";
		}
		
		leaf dynamic-hostname {
			type string;
			
			description 
			 "This leaf describes the name of the node.
			 ISIS reference is TLV 137.";
		}
		
		leaf ipv6-te-routerid {
			type inet:ipv6-address;
			description 
			 "This leaf describes the IPv6 Traffic Engineering 
			  router ID of the node.
			  ISIS reference is TLV 140.";
		}
		
		
		container mt-is-neighbor {
			list neighbor {
				key "neighbor-id";
				leaf MT-ID {
					type uint16 {
						range "0 .. 4095";
					}
					description
					 "This leaf defines the identifier
					  of a topology.";
				}
				uses neighbor-extended;
				description
				 "List of neighbors.";
			}
			description 
			 "This container describes list of ISIS multi-topology 
			  neighbors.
			  ISIS reference is TLV 223.";
		}
		
		container mt-entries {
			list topology {
				key "MT-ID";
				
				leaf MT-ID {
					type uint16 {
						range "0 .. 4095";
					}
					description
					 "This leaf defines the identifier
					  of a topology.";
				}
				
				leaf attributes {
					type bits {
						bit OVERLOAD {
							description
							 "If set, the originator is overloaded,
							  and must be avoided in path 
							  calculation.";
						}
						bit ATTACHED {
							description
							 "If set, the originator is attached to
							  another area using the referred metric.";
						}
					}
					description
					 "This leaf describes attributes of the LSP
					  for the associated topology.";
				}
				description
				 "List of topologies supported.";
			}
			description 
			 "This container describes the topology supported.
			 ISIS reference is TLV 229.";
		}
		
		leaf-list ipv6-addresses {
			type inet:ipv6-address;
			description 
			 "This leaf describes the IPv6 interface 
			 addresses of the node.
			 ISIS reference is TLV 232.";
		}
		
		


		container mt-extended-ipv4-reachability {
			list prefixes {
				key "ip-prefix";
				leaf MT-ID {
					type uint16 {
						range "0 .. 4095";
					}
					description
					 "This leaf defines the identifier
					  of a topology.";
				}
				uses prefix-ipv4-extended;
				description
				 "List of prefixes.";
			
			}
			description 
			 "This container describes list of IPv4 
			 reachability information in multi-topology
			 environment.
			 ISIS reference is TLV 235.";
		}
		
		container mt-ipv6-reachability {
			list prefixes {
				key "ip-prefix";
				leaf MT-ID {
					type uint16 {
						range "0 .. 4095";
					}
					description
					 "This leaf defines the identifier
					  of a topology.";
				}
				uses prefix-ipv6-extended;
				description
				 "List of prefixes.";
			}
			description 
			 "This container describes list of IPv6 
			 reachability information in multi-topology
			 environment.
			 ISIS reference is TLV 237.";
		}
		
		container ipv6-reachability {
			list prefixes {
				key "ip-prefix";
				uses prefix-ipv6-extended;
				description
				 "List of prefixes.";
			}
			description 
			 "This container describes list of IPv6 
			 reachability information.
			 ISIS reference is TLV 236.";
		}
		
		container router-capabilities {
			leaf binary {
				type binary;
				description
				 "This leaf describes the capability of the node.
				 Format is binary according to the protocol encoding.";
			}
			description 
			 "This container describes the capabilities of the node. 
			 This container may be extended with detailed 
			 information.
			 ISIS reference is TLV 242.";
		}
	}
	
	
	
	
	
	augment "/rt:routing/rt:routing-instance/rt:routing-protocols/"
	    +"rt:routing-protocol" {
		when "rt:type = 'isis:isis'" {
			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.";
					description
					 "Enforce configuration of at least one area.";
				}	

				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 the 
						enclosing routing-instance.";
				}
				
				leaf level-type {
					type level;
					default "level-all";
					description
					 "This leaf describes the type of ISIS node.
					 A node can be level-1-only, level-2-only 
					 or level-1-2.
					 ";
				}
				
				leaf system-id {
					type system-id;
					description
					 "This leaf defines the system-id of the node.";
				}
				
				
				leaf maximum-area-addresses {
					if-feature maximum-area-addresses;
					type uint8;
					default 3;
					description
					 "Defines the maximum areas supported.";
				}
				
				leaf-list area-address {
					type area-address;
					description 
					 "List of areas supported by the 
					 protocol instance.";
				}
				
				container mpls-te {
					leaf ipv4-router-id {
						if-feature ipv4-router-id;
						type inet:ipv4-address;
						description 
						 "Router ID value that would be used in 
						 TLV 134.";
					}
					leaf ipv6-router-id {
						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.";
				}
				leaf reference-bandwidth {
					if-feature reference-bandwidth;
					type uint32;
					units "bps";
					description 
					 "This leaf defines the bandwidth for calculating 
					  metric.";
				}
				
				leaf lsp-mtu {
					type uint16;
					units "bytes";
					default 1492;
					description 
					 "This leaf describes the maximum size of a 
					  LSP PDU in bytes.";
				}
				leaf lsp-lifetime {
					type uint16;
					units "seconds";
					description 
					 "This leaf describes the lifetime of the router 
					  LSP in seconds.";
				}
				leaf lsp-refresh {
					if-feature lsp-refresh;
					type uint16;
					units "seconds";
					description 
					 "This leaf describes the refresh interval of the 
					  router LSP in seconds.";
				}
				
				container graceful-restart {
					if-feature graceful-restart;
					leaf enabled {
						type boolean;
						description
						 "Control enabling the feature.";
					}
					description
					 "This container activates graceful restart.";
				}
				
				list authentication {
					key level;
					
					leaf key {
						type string;
						description
						 "This leaf describes the
						 authentication key.";	
					}
					leaf type {
						type authentication-type;
						description
						 "This leaf describes the authentication 
						  type to be used.";
					}
					leaf level {
						type level;
						description
							"Level applicability.";
					}
					description
					 "Container for ISIS authentication. 
					  It covers both LSPs and SNPs.";
				}
				

				
				list metric-type {
					key level;
					
					leaf value {
						type enumeration {
							enum wide-only {
								description 
								 "Advertise new metric style only 
								 (RFC5305)";
							}
							enum old-only {
								description 
								 "Advertise old metric style only 
								 (RFC1195)";
							}
							enum both {
								description "Advertise both metric 
								styles";
							}
						}
						description 
						 "This leaf describes the type of metric 
						 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.
						 This leaf is only affecting IPv4 metrics.";
					}
					leaf level {
						type level;
						description
							"Level applicability.";
					}
					description
					 "Metric style container.";
				}
				list preference {
					key level;
					
					choice granularity {
						case detail {
							leaf internal {
								type uint8;
								description 
									"This leaf defines the protocol 
									 preference for internal routes.";
							}
							leaf external {
								type uint8;
								description 
									"This leaf defines the protocol 
									 preference for external routes.";
							}
						}
						case coarse {
							leaf default {
								type uint8;
								description 
									"This leaf defines the protocol 
									 preference for all ISIS routes.";
							}
						}
						description
						 "Choice for implementation of route preference.";
					}
					
					leaf level {
						type level;
						description
							"Level applicability.";
					}
					description 
						 "This leaf defines the protocol preference.";
				}
				
				list default-metric {
					key level;
					
					leaf value {
						type wide-metric;
						description
							"Value of the metric";
					}
					leaf level {
						type level;
						description
							"Level applicability of the metric.";
					}
					description
					 "Defines the metric to be used by default.";
				}
				list af {
					if-feature nlpid-control;
					key af;
					leaf af {
						type string;
						description
						 "Address-family";
					}
					
					leaf enabled {
						type boolean;
						description
							"Describes the activation state of the 
							 AF.";
					}
					description
					 "This list permits activation
					 of new address families.";
					
				}
				
				
				list topologies {
					if-feature multi-topology;
					
					key "name";
					leaf enabled {
						type boolean;
						description
							"Describes the activation state of the 
							 AF.";
					}
					leaf name {
						type rt:rib-ref;
						description "RIB";					
					}
					list default-metric {
						key level;
						
						leaf value {
							type wide-metric;
							description
								"Value of the metric";
						}
						leaf level {
							type level;
							description
								"Level applicability of the metric.";
						}
						description
						 "Defines the metric to be used by default.";
					}
					description
						"List of topologies";
				}
				
				
				list overload {
					key level;
					
					leaf status {
						type boolean;
						description
						 "This leaf defines the overload status.";
					}
					
					leaf timeout {
						type uint16;
						units "seconds";
						description
						 "This leaf defines the timeout in seconds
						  of the overload condition.";
					}
					leaf level {
						type level;
						description
							"Level applicability of the metric.";
					}
					description 
					 "This leaf describes if the router is 
					  set to overload state.";
				}
				
				list overload-max-metric {
					if-feature overload-max-metric;
					key level;
					
					leaf status {
						type boolean;
						description
						 "This leaf defines the overload status.";
					}
					
					leaf timeout {
						type uint16;
						units "seconds";
						description
						 "This leaf defines the timeout in seconds
						  of the overload condition.";
					}
					leaf level {
						type level;
						description
							"Level applicability of the metric.";
					}
					description 
					 "This leaf describes if the router is 
					  set to overload state.";
				}

				container interfaces {		
					list interface {
						key "name";
						leaf name {
							type string;
							
							description 
							 "Reference to the interface within
							  the routing-instance.";
						}
						leaf level-type {
							type level;
							default "level-all";
							description 
							 "This leaf defines the associated ISIS 
							 level of the interface.";
						}
						leaf lsp-pacing-interval {
							type uint16;
							units "milliseconds";
							description 
							 "This leaf defines the interval between 
							  LSP transmissions in milli-seconds";
						}
						leaf lsp-retransmit-interval {
							type uint16;
							units "seconds";
							description 
							 "This leaf defines the interval between 
							 retransmission of LSP";
						}
						leaf passive {
							type boolean;
							default "false";
							description 
							 "This leaf defines if interface is in 
							  passive mode (ISIS not running, 
							  but network is advertised).";
						}
						leaf csnp-interval {
							type uint16;
							units "seconds";
							description 
							 "This leaf defines the interval of CSNP 
							  messages.";
						}
	
						container hello-padding {
							leaf enabled {
								type boolean;
								default "true";
								description
								 "Status of Hello-padding activation.
								  By default, the implementation shall
								  pad HELLOs.";
							}
							
							description 
							 "This container handles ISIS hello padding
							  configuration.";
						}
						
						leaf mesh-group-enabled {
							type mesh-group-state;
							description
							 "Describes the mesh group state of
							  the interface.";
						}
						
						
						leaf mesh-group {
							when "../mesh-group-enabled = meshSet" {
								description
								 "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 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 {
							type boolean;
							default "true";
							description
							 "This leaf describes the administrative 
							 status of the ISIS interface.";
							  
						}
						
						leaf-list tag {
							if-feature prefix-tag;
							
							type uint32;
							description 
							 "This leaf defines list of tags associated 
							  with the interface.";
						}
						
						leaf-list tag64 {
							if-feature prefix-tag64;
							
							type uint64;
							description 
							 "This leaf defines list of 64bits tags 
							 associated with the interface.";
						}
						
						list hello-authentication {
							key level;
							
							leaf type {
								type authentication-type;
								
								description
								 "This leaf describes the authentication 
								 type to be used in hello messages.";
							}
							leaf key {
								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 the 
								 authentication-key";
							}
							leaf level {
								type level;
								description
									"Level applicability.";
							}
							description
							 "This leaf describes the authentication type
							 to be used in hello messages.";
						}
						
						list hello-interval {
							key level;
							
							leaf value {
								type uint16;
								units "seconds";
								description 
								 "This leaf defines the interval of 
								 hello messages.";
							}
							leaf level {
								type level;
								description
									"Level applicability.";
							}
							description 
								 "This leaf defines the interval of 
								 hello messages.";
						}
						list hello-multiplier {
							key level;
							
							leaf value {
								type uint16;
								description 
								 "This leaf defines the number of 
								 hello failed to be received before 
								 declaring the adjacency down.";
							}
							leaf level {
								type level;
								description
									"Level applicability.";
							}
							description 
								 "This leaf defines the number of 
								  hello failed to be received before 
								  declaring the adjacency down.";
						}
						
						
						list priority {
							must 'interface-type = "broadcast"';
							key level;
							leaf value {
								type uint8 {
									range "0 .. 127";
								}
								
								description
								 "This leaf describes the priority of 
								 the interface
								 for DIS election.";
							}
							leaf level {
								type level;
								description
									"Level applicability.";
							}
							description
								 "This leaf describes the priority of 
								 the interface
								 for DIS election.";
						}
						list metric {
							key level;
							
							leaf value {
								type wide-metric;
								description
								 "Metric value.";
							}
							leaf level {
								type level;
								description
									"Level applicability.";
							}
							description
							 "Container for interface metric";
						}
						list af {
							key af;
							
							leaf af {
								type string;
								description 
									"Address-family"; 
							}
							container bfd {
								if-feature bfd;
								leaf enabled {
									type boolean;
									default false;
									description
									 "This leaf 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 value {
									type wide-metric;
									description
									 "Metric value.";
								}
								leaf level {
									type level;
									description
										"Level applicability.";
								}
								description
								 "Container for interface metric";
							}
							description
							 "List of topologies.";
						}
				
						description
						 "List of ISIS interfaces.";
					}
					description
					 "This container defines ISIS interface specific 
					 configuration objects.";
				}
				description 
					"List of ISIS instances.";
			}
			description 
			 "This container defines ISIS specific configuration
			  objects.";
		}
	}
	
	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 type is isis.";
		}
		description
		 "This augments routing protocol instance states with ISIS
		  specific parameters.";
		container isis {
			config false;
			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 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 interface-counters {
				list interface {
					key interface;
					
					leaf interface {
						type string;
						description
						 "This leaf describes the name
						 of the interface.";
					}
					
					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.";
			}
			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.";
					}
					leaf three-way-handshake {
						type empty;
						description
						 "The interface uses 3-way handshake.";
					}
					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 {
						type level;
						description 
							"This leaf describes the associated 
							ISIS level of the interface.
							";
					}
					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 {
						type level;
						description
						"The type of the neighboring system.";
					}
					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.";
							}
						}
						description
						 "This leaf describes the state of the
						 interface.";
					}
					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.";
					}
					
					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 
			 "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:

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", Internet-Draft draft-ietf-netmod-routing-cfg-15, May 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