



Internet                                                           Y. Qu
Internet-Draft                                    Futurewei Technologies
Intended status: Standards Track                             L. Ginsberg
Expires: 25 October 2026                                   Cisco Systems
                                                           A. Przygienda
                                                        Juniper Networks
                                                             B. Decraene
                                                                  Orange
                                                                  Y. Zhu
                                                           China Telecom
                                                           23 April 2026


   YANG Model for IS-IS Protocol Implementation Conformance Statement
                                 (PICS)
                    draft-ietf-lsr-isis-pics-yang-03

Abstract

   The YANG model in this document is to be used to query an IS-IS
   Protocol Implementation Conformance Statement (PICS).

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 25 October 2026.

Copyright Notice

   Copyright (c) 2026 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



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   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Design of the Model . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  IANA IS-IS PICS YANG Module . . . . . . . . . . . . . . .   3
     3.2.  IS-IS PICS YANG Module  . . . . . . . . . . . . . . . . .   3
   4.  IS-IS PICS YANG Trees . . . . . . . . . . . . . . . . . . . .   4
     4.1.  IETF IS-IS PICS YANG Tree . . . . . . . . . . . . . . . .   4
   5.  IS-IS PICS YANG Modules . . . . . . . . . . . . . . . . . . .   4
     5.1.  IANA ISIS PICS YANG Module  . . . . . . . . . . . . . . .   4
     5.2.  IS-IS PICS Module . . . . . . . . . . . . . . . . . . . .   5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Registering YANG Modules  . . . . . . . . . . . . . . . .   7
     7.2.  IANA ISIS-PICS Module . . . . . . . . . . . . . . . . . .   8
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   8
   10. Informative References  . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Overview

   YANG [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.














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   Operators may find it useful to know what aspects of a protocol are
   implemented by a given node in their network.  Historically this
   information has been provided in a Protocol Implementation
   Conformance Statement (PICS) which is available as an offline
   document.  (An example of PICS for IS-IS can be found in [ISO10589]
   Section 12.)  However, there is no reason why this information could
   not be provided via YANG - which is what this document defines.  This
   allows an operator to query nodes in real time as to what protocol
   features are supported.  This in turn can assist with avoiding (or at
   least diagnosing) interoperability problems and/or determining when a
   feature can be safely deployed.

   The YANG modules in this document conform to the Network Management
   Datastore Architecture (NMDA) [RFC8342].

1.1.  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] [RFC8174].

2.  Tree Diagrams

   This document uses the graphical representation of data models
   defined in [RFC8340].

3.  Design of the Model

3.1.  IANA IS-IS PICS YANG Module

   A new IANA registry will be created for IS-IS PICS, which maintains
   the list of RFCs that support IS-IS PICS.

   Module iana-isis-pics.yang is the initial version for IS-IS PICS
   identity type definitions.

   When a new identity is added to the "IS-IS PICS" registry, the iana-
   isis-pics YANG module is updated by IANA.

3.2.  IS-IS PICS YANG Module

   Module ietf-isis-pics.yang is a device model and designed to query a
   node with IS-IS PICS status.

   The leaf-list of "isis-pics" lists all the supported PICS that
   defined in the iana-isis-pics module.





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   The container "isis-pics-mptlv" is a place holder and meant to be
   augmented by individual RFC PICS module with multi-part tlv support.

4.  IS-IS PICS YANG Trees

4.1.  IETF IS-IS PICS YANG Tree

   The following figure shows the tree diagram of the ietf-isis-pics
   module.

   module: ietf-isis-pics
     +--ro isis-pics
        +--ro supported-isis-pics*   identityref
        +--ro isis-pics-mptlv

5.  IS-IS PICS YANG Modules

5.1.  IANA ISIS PICS YANG Module

   <CODE BEGINS> file "iana-isis-pics@2024-03-03.yang"
   module iana-isis-pics {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-isis-pics";
     prefix iana-isis-pics;

     organization
       "IANA";
     contact
       "Internet Assigned Numbers Authority

        Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA 90094-2536
                United States of America
        Tel:    +1 310 301 5800
        <mailto:iana@iana.org>";

     description
       "The YANG module defines the identities for IS-IS Protocol
        Implementation Conformance Statement (PICS).

        Copyright (c) 2025 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Revised BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions



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        Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
        for full legal notices.";

     revision 2025-05-05 {
       description
         "Initial Version";
       reference
         "RFC XXXX: YANG Data Model for IS-IS PICS.";
     }


     identity isis-pics {
       description
         "This identity is used as a base for all ISIS pics defined
          in the 'IS-IS PICS' registry.";
     }

   }
   <CODE ENDS>

5.2.  IS-IS PICS Module

   <CODE BEGINS> file "ietf-isis-pics@2025-05-05.yang"
   module ietf-isis-pics {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-isis-pics";
     prefix isis-pics;

     import iana-isis-pics {
       prefix "iana-isis-pics";
     }

     organization
       "IETF LSR - Link State Routing Working Group";
     contact
       "WG Web:   <http://datatracker.ietf.org/wg/lsr>
        WG List:  <mailto:lsr@ietf.org>

        Author:   Yingzhen Qu
                  <mailto:yingzhen.ietf@gmail.com>
        Author:   Les Ginsberg
                  <mailto:ginsberg@cisco.com>
        Author:   Tony Przygienda
                  <mailto:prz@juniper.net>



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        Author:   Bruno Decraene
                  <mailto:bruno.decraene@orange.com>
        Author:   Yongqing Zhu
                  <mailto:zhuyq8@chinatelecom.cn>";

     description
       "The YANG module is used to query an IS-IS implementation
        for Protocol Implementation Conformance Statement (PICS).

        This YANG model conforms to the Network Management
        Datastore Architecture (NMDA) as described in RFC 8342.

        Copyright (c) 2025 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Revised BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
        for full legal notices.";

     reference
       "RFC XXXX: YANG Data Model for IS-IS PICS";

     revision 2025-05-05 {
       description
         "Initial Version";
       reference
         "RFC XXXX: YANG Data Model for IS-IS PICS.";
     }

     typedef support {
       type boolean;
       default "false";
       description
         "When set to True, it means a feature or definition is
          supported/implemented.";
     }

     container isis-pics {
       config false;
       description
         "IS-IS Protocol Implementation Conformance Statement (PICS).";



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       leaf-list supported-isis-pics {
         type identityref {
           base iana-isis-pics:isis-pics;
         }
         description
           "List of supported isis pics.";
       }

       container isis-pics-mptlv {

         description
           "IS-IS Protocol Implementation Conformance Statement (PICS)
            for RFC xxxx: Multi-part TLVs in IS-IS. This container is
            meant to be augmented by RFC PICS module where a TLV is
            defined.";
       }
     }
   }
   <CODE ENDS>

6.  Security Considerations

   The YANG modules defined in this document are designed to be accessed
   via YANG-based management protocols, such as NETCONF [RFC6241] and
   RESTCONF [RFC8040].  These protocols have to use a secure transport
   layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) and
   have to use mutual authentication.

   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   Some of the readable data nodes in the ietf-isis-pics.yang module may
   be considered sensitive or vulnerable in some network environments.
   It is thus important to control read access (e.g., via get, get-
   config, or notification) to these data nodes.

7.  IANA Considerations

7.1.  Registering YANG Modules

   This document registers URIs in the IETF XML registry as defined in
   [RFC3688].  The following registrations are requested to be made:

      URI: urn:ietf:params:xml:ns:yang:iana-isis-pics
      Registrant Contact: IANA.
      XML: N/A, the requested URI is an XML namespace.



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      URI: urn:ietf:params:xml:ns:yang:ietf-isis-pics
      Registrant Contact: The IESG.
      XML: N/A, the requested URI is an XML namespace.

   This document registers the following two YANG module in the "YANG
   Module Names" registry [RFC6020].

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

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

7.2.  IANA ISIS-PICS Module

   This document defines the initial version of the IANA-maintained
   iana-isis-pics YANG module.

   The document requests IANA to create a "IS-IS PICS" registry, and
   iana-isis-pics YANG module is intended to reflect the the registry.

   When a IS-IS PICS moduel is published, it MUST define how a new
   "identity" statement should be added to the iana-isis-pics module.
   The following guidlines should be followed.

   The name of the "identity" is "isis-pics-" plus the lowercase of the
   RFC name abbreviation.  The "identity" statement should have the
   following substatements defined:

     "base":        contains the value of "isis-pics".
     "description": contains "The identity for IS-IS PICS support of
                    xxxx.", replace the "xxxx" with the RFC information.
     "reference":   the corresponding RFC information.

   When the iana-isis-pis YANG module is updated, a new "revision"
   statement must be added in from of the existing revision statements.

8.  Acknowledgements

   The YANG model was developed using the suite of YANG tools written
   and maintained by numerous authors.

9.  Normative References




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

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4252]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
              January 2006, <https://www.rfc-editor.org/info/rfc4252>.

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

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

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.



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   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/info/rfc9000>.

   [ISO10589] ISO, "Intermediate system to Intermediate system routing
              information exchange protocol for use in conjunction with
              the Protocol for providing the Connectionless-mode Network
              Service (ISO 8473)", August 1987, <ISO/IEC 10589:2002>.

10.  Informative References

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Authors' Addresses

   Yingzhen Qu
   Futurewei Technologies
   Email: yingzhen.ietf@gmail.com


   Les Ginsberg
   Cisco Systems
   Email: ginsberg@cisco.com.com


   Antoni Przygienda
   Juniper Networks
   Email: prz@juniper.net


   Bruno Decraene
   Orange
   Email: bruno.decraene@orange.com


   Yongqing Zhu
   China Telecom
   Email: zhuyq8@chinatelecom.cn










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