IS-IS Working Group S. Litkowski
Internet-Draft Orange
Intended status: Standards Track Y. Qu
Expires: July 19, 2018 Huawei
P. Sarkar
Individual
I. Chen
Jabil
J. Tantsura
Individual
January 15, 2018

YANG Data Model for IS-IS Segment Routing
draft-ietf-isis-sr-yang-03

Abstract

This document defines a YANG data model that can be used to configure and manage IS-IS Segment Routing ([I-D.ietf-isis-segment-routing-extensions].

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 https://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 July 19, 2018.

Copyright Notice

Copyright (c) 2018 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 (https://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. Overview

YANG [RFC6020] [RFC7950] is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF [RFC6241]. YANG is proving relevant beyond its initial confines, as bindings to other interfaces (e.g., ReST) and encodings other than XML (e.g., JSON) are being defined. Furthermore, YANG data models can be used as the basis for implementation of other interfaces, such as CLI and programmatic APIs.

This document defines a YANG data model that can be used to configure and manage IS-IS Segment Routing and it is an augmentation to the IS-IS YANG data model.

2. IS-IS Segment Routing

This document defines a model for IS-IS Segment Routing feature. It is an augmentation of the IS-IS base model.

The IS-IS SR YANG module requires support for the base segment routing module [I-D.ietf-spring-sr-yang], which defines the global segment routing configuration independent of any specific routing protocol configuration, and support of IS-IS base model [I-D.ietf-isis-yang-isis-cfg] which defines basic IS-IS configuration and state.

The figure below describes the overall structure of the isis-sr YANG module:

module: ietf-isis-sr
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis:
   +--rw segment-routing
   |  +--rw enabled?    boolean
   |  +--rw bindings
   |     +--rw advertise
   |     |     ...
   |     +--rw receive?     boolean
   +--rw protocol-srgb {sr:protocol-srgb}?
      +--rw srgb* [lower-bound upper-bound]
         +--rw lower-bound    uint32
         +--rw upper-bound    uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:interfaces/isis:interface:
   +--rw segment-routing
      +--rw adjacency-sid
         +--rw advertise-adj-group-sid* [group-id]
         |     ...
         +--rw advertise-protection?      enumeration
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:interfaces/isis:interface/isis:fast-reroute:
   +--rw ti-lfa {ti-lfa}?
      +--rw enable?   boolean
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:interfaces/isis:interface/isis:fast-reroute/isis:lfa/isis:remote-lfa:
   +--rw use-segment-routing-path?   boolean {remote-lfa-sr}?
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:interfaces/isis:interface/isis:adjacencies/isis:adjacency:
   +--ro adjacency-sid* [value]
      +--ro af?                     iana-rt-types:address-family
      +--ro value                   uint32
      +--ro weight?                 uint8
      +--ro protection-requested?   boolean
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:router-capabilities:
   +--ro sr-capability
   |  +--ro flags?           bits
   |  +--ro global-blocks
   |     +--ro global-block*
   |           ...
   +--ro sr-algorithms
   |  +--ro sr-algorithm*   uint8
   +--ro local-blocks
   |  +--ro local-block*
   |     +--ro range-size?    uint32
   |     +--ro sid-sub-tlv
   |           ...
   +--ro srms-preference
      +--ro preference?   uint8
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:extended-is-neighbor/isis:neighbor:
   +--ro sid-list* [value]
      +--ro flags?         bits
      +--ro weight?        uint8
      +--ro neighbor-id?   isis:system-id
      +--ro value          uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:mt-is-neighbor/isis:neighbor:
   +--ro sid-list* [value]
      +--ro flags?         bits
      +--ro weight?        uint8
      +--ro neighbor-id?   isis:system-id
      +--ro value          uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:extended-ipv4-reachability/isis:prefixes:
   +--ro sid-list* [value]
      +--ro flags?       bits
      +--ro algorithm?   uint8
      +--ro value        uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:mt-extended-ipv4-reachability/isis:prefixes:
   +--ro sid-list* [value]
      +--ro flags?       bits
      +--ro algorithm?   uint8
      +--ro value        uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:ipv6-reachability/isis:prefixes:
   +--ro sid-list* [value]
      +--ro flags?       bits
      +--ro algorithm?   uint8
      +--ro value        uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp/isis:mt-ipv6-reachability/isis:prefixes:
   +--ro sid-list* [value]
      +--ro flags?       bits
      +--ro algorithm?   uint8
      +--ro value        uint32
augment /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol/isis:isis/isis:database/isis:level-db/isis:lsp:
   +--ro segment-routing-bindings* [fec range]
      +--ro fec        string
      +--ro range      uint16
      +--ro flags?     bits
      +--ro binding
         +--ro prefix-sid
               ...

3. IS-IS Segment Routing configuration

3.1. Segment Routing activation

Activation of segment-routing IS-IS is done by setting the "enable" leaf to true. This triggers advertisement of segment-routing extensions based on the configuration parameters that have been setup using the base segment routing module.

3.2. Advertising mapping server policy

The base segment routing module defines mapping server policies. By default, IS-IS will not advertise nor receive any mapping server entry. The IS-IS segment-routing module allows to advertise one or multiple mapping server policies through the "bindings/advertise/policies" leaf-list. The "bindings/receive" leaf allows to enable the reception of mapping server entries.

3.3. IP Fast reroute

IS-IS SR model augments the fast-reroute container under interface. It brings the ability to activate TI-LFA (topology independent LFA) and also enhances remote LFA to use segment-routing tunneling instead of LDP.

4. IS-IS Segment Routing YANG Module

<CODE BEGINS> file "ietf-isis-sr@2018-01-15.yang"

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

  
  import ietf-routing {
    prefix "rt";
  }
  
  import ietf-segment-routing-common {
	prefix "sr-cmn";
  }
  
   
  import ietf-segment-routing {
	prefix "sr";
  }
  
  import ietf-isis {
	prefix "isis";
  }
  
  import iana-routing-types {
    prefix "iana-rt-types";
  }
  
  organization
   "IETF ISIS Working Group";
   
  contact
    "WG List:  &lt;mailto:spring@ietf.org&gt;
    
    Editor:    Stephane Litkowski
          &lt;mailto:stephane.litkowski@orange.com&gt;

        Acee Lindem
          &lt;mailto:acee@cisco.com&gt;
		Yingzhen Qu
		  &lt;mailto:yiqu@cisco.com&gt;
        Pushpasis Sarkar
          &lt;mailto:pushpasis.ietf@gmail.com&gt;
        Ing-Wher Chen
          &lt;mailto:ichen@kuatrotech.com&gt;
		Jeff Tantsura
		  &lt;mailto:jefftant.ietf@gmail.com&gt;
		  
    ";
  
  description 
    "The YANG module defines a generic configuration model for 
    Segment routing ISIS extensions common across all of the vendor 
    implementations.";

  revision 2018-01-15 {
	description
		"Initial revision.";
	reference "RFC XXXX";
  }

  
  /* Identities */
  
  
  /* Features */
  
feature remote-lfa-sr {
	description
	 "Enhance rLFA to use SR path.";
}

feature ti-lfa {
	description
	 "Enhance IPFRR with ti-lfa 
	 support";
}
  
  /* Groupings */
 

grouping sid-sub-tlv {
	description "SID/Label sub-TLV grouping.";
	container sid-sub-tlv {
	  description
		"Used to advertise the SID/Label associated with a
		 prefix or adjacency.";
	  leaf sid {
		type uint32;
		description
		  "Segment Identifier (SID) - A 20 bit label or
		   32 bit SID.";
	  }
	}
}

grouping sr-capability {
	description
	"SR capability grouping.";
	container sr-capability {
	  description
	   "Segment Routing capability.";
	  leaf flags {
        type bits {
          bit mpls-ipv4 {
            position 0;
            description
             "If set, then the router is capable of
         processing SR MPLS encapsulated IPv4 packets 
		 on all interfaces.";
          }
		  bit mpls-ipv6 {
            position 1;
            description
             "If set, then the router is capable of
         processing SR MPLS encapsulated IPv6 packets 
		 on all interfaces.";
          }
	    }
		description
		 "Flags.";
      }
	  container global-blocks {
		description 
		"Segment Routing Global Blocks.";
		list global-block {
			description "Segment Routing Global Block.";
			leaf range-size {
			  type uint32;
			  description "The SID range.";
			}
			uses sid-sub-tlv;
		}
	  }
	}
}

grouping sr-algorithm {
	description
	 "SR algorithm grouping.";
	container sr-algorithms {
      description "All SR algorithms.";
      leaf-list sr-algorithm {
        type uint8;
        description
          "The Segment Routing (SR) algorithms that the router is
           currently using.";
      }
    }
}

grouping srlb {
	description
	 "SR Local Block grouping.";
    container local-blocks {
      description "List of SRLBs.";
      list local-block {
        description "Segment Routing Local Block.";
        leaf range-size {
          type uint32;
          description "The SID range.";
        }
        uses sid-sub-tlv;
      }
    }
}

grouping srms-preference {
    description "The SRMS preference TLV is used to advertise
                 a preference associated with the node that acts
                 as an SR Mapping Server.";
    container srms-preference {
      description "SRMS Preference TLV.";
      leaf preference {
        type uint8 {
          range "0 .. 255";
        } 
		description "SRMS preference TLV, vlaue from 0 to 255.";
      }
    }
  }  

grouping adjacency-state {
	description
	 "This group will extend adjacency state.";
	list adjacency-sid {
	  key value;
	  config false;
	  leaf af {
		type iana-rt-types:address-family;
		description
		 "Address-family associated with the 
		 segment ID";
	  }
	  leaf value {
		type uint32;
		description
		 "Value of the Adj-SID.";
	  }
	  leaf weight {
		type uint8;
		description
		 "Weight associated with
		 the adjacency SID.";
	  }
	  leaf protection-requested {
		type boolean;
		description
		 "Describe if the adjacency SID
		 must be protected.";
	  }
	  description
	   "List of adjacency Segment IDs.";
	}
}

grouping prefix-segment-id {
    description
     "This group defines segment routing extensions
     for prefixes.";
    
	list sid-list {
	  key value;
	  
      leaf flags {
        type bits {
          bit readvertisment {
            position 7;
            description
             "If set, then the prefix to
            which this Prefix-SID is attached, 
            has been propagated by the
            router either from another level
            or from redistribution.";
          }

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


          }
          bit  local {
            position 2;
            description
            "If set, then the value/index carried by
            the Prefix-SID has local significance.  
            By default the flag is UNSET.";
          }
        }
        description
         "Describes flags associated with the
         segment ID.";
      }
      
      leaf algorithm {
        type uint8;
        description
         "Algorithm to be used for path computation.";
      }
      leaf value {
        type uint32;
        description
         "Value of the prefix-SID.";
      }
	  description
	   "List of segments.";
    }
  }
  
  grouping adjacency-segment-id {
    description
     "This group defines segment routing extensions
     for adjacencies.";
    
	list sid-list {
	  key value;
	  
      leaf flags {
        type bits {
          bit address-family {
            position 7;
            description
             "If unset, then the Adj-SID refers
            to an adjacency with outgoing IPv4 encapsulation.  
            If set then the Adj-SID refers to an adjacency 
            with outgoing IPv6 encapsulation.";
          }
          bit backup {
            position 6;
            description
             "If set, the Adj-SID refers to an
            adjacency being protected 
            (e.g.: using IPFRR or MPLS-FRR)";
          }
          bit value {
            position 5;
            description
            "If set, then the SID carries a
            value (instead of an index).  
            By default the flag is SET.";


          }
          bit local {
            position 4;
            description
            "If set, then the value/index carried by
            the SID has local significance.  
            By default the flag is SET.";
          }
          bit set {
            position 3;
            description
            "When set, the S-Flag indicates that the
            Adj-SID refers to a set of adjacencies.";
          }
		  bit persistent {
            position 2;
            description
            "When set, the P-Flag indicates that the
                  Adj-SID is persistently allocated.";
          }
        }
        
        description
         "Describes flags associated with the
         segment ID.";
      }
      leaf weight {
        type uint8;
        description
         "The value represents the weight of the Adj-SID
          for the purpose of load balancing.";
      }
      leaf neighbor-id {
        type isis:system-id;
        description
         "Describes the system ID of the neighbor
         associated with the SID value. This is only
         used on LAN adjacencies.";
      }
      leaf value {
        type uint32;
        description
         "Value of the Adj-SID.";
      }
	  description
	   "List of segments.";
    }

  }
  grouping segment-routing-binding-tlv {
  list segment-routing-bindings {
      
      key "fec range";
      
      leaf fec {
        type string;
        description
        "IP (v4 or v6) range to be bound to SIDs.";
      }
      
      leaf range {
        type uint16;
        description
         "Describes number of elements to assign 
         a binding to.";
      }
      
      leaf flags {
        type bits {
          bit address-family {
            position 7;
            description
            "If unset, then the Prefix FEC
            carries an IPv4 Prefix.  
            If set then the Prefix FEC carries an
            IPv6 Prefix.";
          }
          bit mirror {
            position 6;
            description
            "Set if the advertised SID/path
            corresponds to a mirrored context.
            ";
          }
          bit flooding {
            position 5;
            description
             "If the S bit is set(1), 
             the IS-IS Router CAPABILITY TLV
            MUST be flooded across the entire routing domain.  
            If the S bit is
            not set(0), the TLV MUST NOT be leaked between levels.  
            This bit MUST NOT be altered during the TLV leaking.";
          }
          bit down {
            position 4;
            description
            "When the IS-IS Router CAPABILITY TLV is 
            leaked from level-2 to level-1, the D bit 
            MUST be set.  Otherwise, this bit MUST
            be clear.  IS-IS Router capability TLVs 
            with the D bit set MUST NOT
            be leaked from level-1 to level-2.  
            This is to prevent TLV looping.
            ";
          }
          bit attached {
            position 3;
            description
            "The originator of the SID/Label Binding
            TLV MAY set the A bit in order to signal
            that the prefixes and
            SIDs advertised in the SID/Label Binding
            TLV are directly
            connected to their originators.
            ";
          }
          
        }
        description
           "Flags of the binding.";
      }
          
      container binding {
        container prefix-sid {
          uses prefix-segment-id;
          description
           "Binding prefix SID to the range.";
        }
        description
         "Bindings associated with the range.";
      }
      
      description 
       "This container describes list of SID/Label
       bindings.
       ISIS reference is TLV 149.";     
    }
	description
	 "Defines binding TLV for database.";
	 
  }
  /* Cfg */
    
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis" {
    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" {
      description
      "This augment ISIS routing protocol when used";
    }
    description
     "This augments ISIS protocol configuration
      with segment routing.";
      
    uses sr:controlplane-cfg;
	container protocol-srgb {
         if-feature sr:protocol-srgb;
         uses sr-cmn:srgb-cfg;
         description
           "Per-protocol SRGB.";
       }
  }
   
   
   augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:interfaces/isis:interface" {
    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" {
      description
      "This augment ISIS routing protocol when used";
    }
    description
     "This augments ISIS protocol configuration
      with segment routing.";
      
    uses sr:igp-interface-cfg;
  }
  
   augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:interfaces/isis:interface"+
		"/isis:fast-reroute" {
    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" {
      description
      "This augment ISIS routing protocol when used";
    }
    description
     "This augments ISIS IP FRR with TILFA.";
      
	container ti-lfa {
		if-feature ti-lfa;
		leaf enable {
			type boolean;
			description
			 "Enables TI-LFA computation.";
		}
		description
		 "TILFA configuration.";
	}

  }
  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:interfaces/isis:interface"+
		"/isis:fast-reroute/isis:lfa/isis:remote-lfa" {
    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" {
      description
      "This augment ISIS routing protocol when used";
    }
    description
     "This augments ISIS remoteLFA config with
	 use of segment-routing path.";
      
	leaf use-segment-routing-path {
		if-feature remote-lfa-sr;
		type boolean;
		description
		 "force remote LFA to use segment routing
		 path instead of LDP path.";
	}

  }
  
  
  
  /* Operational states */
  

  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:interfaces/isis:interface" +
		"/isis:adjacencies/isis:adjacency" {
    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
    description
     "This augments ISIS protocol configuration
      with segment routing.";
      
	
    uses adjacency-state;
  }
  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:router-capabilities" {
	 when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
	description
	 "This augments ISIS protocol LSDB router capability.";
	 
	uses sr-capability;
	uses sr-algorithm;
	uses srlb;
	uses srms-preference;
  
  }
  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:extended-is-neighbor/isis:neighbor" {
	 when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
	description
	 "This augments ISIS protocol LSDB neighbor.";
	uses adjacency-segment-id;
  
  }
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:mt-is-neighbor/isis:neighbor" {
		    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB neighbor.";
	uses adjacency-segment-id;
  }
  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:extended-ipv4-reachability/isis:prefixes" {
		    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB prefix.";
	uses prefix-segment-id;
  }
  
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:mt-extended-ipv4-reachability/isis:prefixes" {
		    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB prefix.";
	uses prefix-segment-id;
  
  }
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:ipv6-reachability/isis:prefixes" {
		    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB prefix.";
	uses prefix-segment-id;
  
  }
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp"+
		"/isis:mt-ipv6-reachability/isis:prefixes" {
		    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB prefix.";
	uses prefix-segment-id;
  
  }
  augment "/rt:routing/" +
        "rt:control-plane-protocols/rt:control-plane-protocol"+
        "/isis:isis/isis:database/isis:level-db/isis:lsp" {
	    when "/rt:routing/rt:control-plane-protocols/"+
		"rt:control-plane-protocol/rt:type = 'isis:isis'" { 
      description
      "This augment ISIS routing protocol when used";
    }
		description
	 "This augments ISIS protocol LSDB.";
	uses segment-routing-binding-tlv;
  
  }
  
  
  /* Notifications */
  
 
}

<CODE ENDS>

5. Security Considerations

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

As IS-IS 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.

6. Contributors

Authors would like to thank Derek Yeung, Acee Lindem, Yi Yang for their major contributions to the draft.

7. Acknowledgements

TBD.

8. IANA Considerations

The IANA is requested to assign two new URIs from the IETF XML registry ([RFC3688]). Authors are suggesting the following URI:

	URI: urn:ietf:params:xml:ns:yang:ietf-isis-sr
	Registrant Contact: IS-IS WG
	XML: N/A, the requested URI is an XML namespace
   

This document also requests one new YANG module name in the YANG Module Names registry ([RFC6020]) with the following suggestion :

	name: ietf-isis-sr
	namespace: urn:ietf:params:xml:ns:yang:ietf-isis-sr
	prefix: isis-sr
	reference: RFC XXXX
   

9. Change log for ietf-isis-sr YANG module

9.1. From version -02 to version -03

9.2. From isis-sr document version -01 to version -02

9.3. From isis-sr document version -00 to version -01

9.4. From isis document version -12 to isis-sr document version -00

9.5. From isis document version -12 to version -13

9.6. From isis document version -09 to version -11

9.7. From isis document version -08 to version -09

9.8. From isis document version -07 to version -08

10. Normative References

[I-D.ietf-isis-segment-routing-extensions] Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A., Gredler, H., Litkowski, S., Decraene, B. and J. Tantsura, "IS-IS Extensions for Segment Routing", Internet-Draft draft-ietf-isis-segment-routing-extensions-15, December 2017.
[I-D.ietf-isis-yang-isis-cfg] Litkowski, S., Yeung, D., Lindem, A., Zhang, Z. and L. Lhotka, "YANG Data Model for IS-IS protocol", Internet-Draft draft-ietf-isis-yang-isis-cfg-19, November 2017.
[I-D.ietf-spring-sr-yang] Litkowski, S., Qu, Y., Sarkar, P. and J. Tantsura, "YANG Data Model for Segment Routing", Internet-Draft draft-ietf-spring-sr-yang-08, December 2017.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012.
[RFC7950] Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016.

Authors' Addresses

Stephane Litkowski Orange EMail: stephane.litkowski@orange.com
Yinghzen Qu Huawei EMail: yingzhen.qu@huawei.com
Pushpasis Sarkar Individual EMail: pushpasis.ietf@gmail.com
Ing-Wher Chen Jabil EMail: ing-wher_chen@jabil.com
Jeff Tantsura Individual EMail: jefftant.ietf@gmail.com