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A YANG Model for MPLS MSD
draft-ietf-mpls-msd-yang-05

Document Type Active Internet-Draft (mpls WG)
Authors Yingzhen Qu , Acee Lindem , Stephane Litkowski , Jeff Tantsura
Last updated 2024-01-24
Replaces draft-qu-mpls-mpls-msd-yang
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draft-ietf-mpls-msd-yang-05
Internet                                                           Y. Qu
Internet-Draft                                    Futurewei Technologies
Intended status: Standards Track                               A. Lindem
Expires: 27 July 2024                            LabN Consulting, L.L.C.
                                                            S. Litkowski
                                                           Cisco Systems
                                                             J. Tantsura
                                                                  Nvidia
                                                         24 January 2024

                       A YANG Model for MPLS MSD
                      draft-ietf-mpls-msd-yang-05

Abstract

   This document defines a YANG data model augmenting the IETF MPLS YANG
   model to provide support for MPLS Maximum SID Depths (MSDs) as
   defined in RFC 8476 and RFC 8491.

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 27 July 2024.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   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 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.  Design of the Model . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  IANA MSD Types Module . . . . . . . . . . . . . . . . . .   3
     2.2.  IETF MPLS MSD Types Module  . . . . . . . . . . . . . . .   3
   3.  Tree for IETF MPLS MSD Types YANG Module  . . . . . . . . . .   3
   4.  YANG Modules  . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

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] or RESTCONF [RFC8040].

   There are two YANG modules defined in this document.  Module iana-
   msd-types defines the identities for Maximum SID Depth (MSD) Types as
   the IANA the IGP MSD-Types registry.  This document also defines
   module ietf-mpls-msd augmenting the IETF MPLS YANG model [RFC8960],
   which itself augments [RFC8349], to provide operational state for
   various MSDs[RFC8662].  The module augments the base MPLS model with
   a list of various types of node MSDs, as well as various types of
   MSDs on links.

   The augmentation defined in this document requires support for the
   MPLS base model[RFC8960] which defines basic MPLS configuration and
   state.  The YANG modules in this document conform to the Network
   Management Datastore Architecture (NMDA) [RFC8342].

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1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Design of the Model

2.1.  IANA MSD Types Module

   Module iana-msd-types is an IANA maintained module, which defines the
   identities in the IANA IGP MSD-Types registry.

   On top of the base identity "msd-base", identity "msd-base-mpls" is
   defined to serve as the base for MSD types for MPLS data plane, and
   identity "msd-base-srh" is defined to serve as the base for MSD types
   for Segment Routing Header (SRH) in IPv6 data plane.

   This module will be maintained by IANA if more MSD types are added to
   the registry.

2.2.  IETF MPLS MSD Types Module

   Module ietf-mpls-msd augments the base MPLS model [RFC8960], and it
   is to provide support of different types of MSDs in MPLS data plane.

   As defined in [RFC8491], MSD is the number of SIDs supported by a
   node or a link on a node.  The module defines lists of MSDs with
   different MSD Types for a node and links.  Please note that these are
   read-only data decided by the node's hardware capability.

3.  Tree for IETF MPLS MSD Types YANG Module

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

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   module: ietf-mpls-msd
     augment /rt:routing/mpls:mpls:
       +--ro node-msd
          +--ro node-msds* [msd-type]
             +--ro msd-type?    identityref
             +--ro msd-value?   uint8
     augment /rt:routing/mpls:mpls/mpls:interfaces/mpls:interface:
       +--ro link-msd
          +--ro link-msds* [msd-type]
             +--ro msd-type?    identityref
             +--ro msd-value?   uint8

4.  YANG Modules

   This document defines an IANA YANG module for MSD Types defined in
   the IANA IGP MSD-Types registry.

   <CODE BEGINS> file "iana-msd-types@2024-01-24.yang"
   module iana-msd-types {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-msd-types";
     prefix iana-msd-types;

     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 Maximum SID Depth
        (MSD) Types.

        Copyright (c) 2024 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).

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        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 2024-01-24 {
       description
         "Initial Version";
       reference
         "RFC XXXX: A YANG Data Model for MPLS MSD..";
     }

     identity msd-base {
       description
         "Base identity for Maximum SID Depth (MSD) Type. The MSD type
          definition is defined in IANA IGP MSD-Types registry.";
     }

     identity msd-base-mpls {
       base msd-base;
       description
         "Identity for MSD types applicable to MPLS data plane.";
     }

     identity msd-mpls {
       base msd-base-mpls;
       description
         "Base MPLS Imposition MSD.";
       reference
         "RFC 8491: Signaling Maximum SID Depth (MSD) using IS-IS
          RFC 8476: Signaling Maximum SID Depth (MSD) using OSPF
          RFC 8664: Path Computation Element Communication Protocol
                    (PCEP) Extensions for Segment Routing
          RFC 8814: Signaling Maximum SID Depth (MSD) Using the Border
                    Gateway Protocol - Link State";
     }

     identity msd-erld {
       base msd-base-mpls;
       description
         "msd-erld is defined to advertise the Entropy Readable
          Label Depth (ERLD).";
       reference
         "RFC 8662: Entropy Label for Source Packet Routing in
                    Networking (SPRING) Tunnels";
     }

     identity msd-base-srh {
       base msd-base;

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       description
         "Identity for MSD types for Segment Routing Header (SRH).";
     }

     identity msd-srh-max-sl {
       base msd-base-srh;
       description
         "The Maximum Segment Left MSD type.";
       reference
         "RFC 9352: IS-IS Extensions to Support Segment Routing
                    over the IPv6 Data Plane";
     }

     identity msd-srh-max-end-pop {
       base msd-base-srh;
       description
         "The Maximum End Pop MSD Type.";
       reference
         "RFC 9352: IS-IS Extensions to Support Segment Routing
                    over the IPv6 Data Plane";
     }

     identity msd-srh-max-hen-cap {
       base msd-base-srh;
       description
         "The Maximum H.Encaps MSD Type.";
       reference
         "RFC 9352: IS-IS Extensions to Support Segment Routing
                    over the IPv6 Data Plane";
     }

     identity msd-srh-max-end-d {
       base msd-base-srh;
       description
         "The Maximum End D MSD Type.";
       reference
         "RFC 9352: IS-IS Extensions to Support Segment Routing
                    over the IPv6 Data Plane";
     }
   }
   <CODE ENDS>

   This document also defines a YANG module for MSD extensions
   [RFC8476][RFC8491] to MPLS base model as defined in [RFC8960].

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   <CODE BEGINS> file "ietf-mpls-msd@2024-01-24.yang"
   module ietf-mpls-msd {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-msd";
     prefix mpls-msd;

     import ietf-routing {
       prefix rt;
       reference
         "RFC 8349: A YANG Data Model for Routing
                    Management (NMDA Version)";
     }
     import ietf-mpls {
       prefix mpls;
       reference
         "RFC 8960: A YANG Data Model for MPLS Base";
     }
     import iana-msd-types {
       prefix iana-msd-types;
     }

     organization
       "IETF Multiprotocol Label Switching (MPLS) Working Group";
     contact
       "WG Web:   <https://datatracker.ietf.org/wg/mpls/>
        WG List:  <mailto:mpls@ietf.org>

        Author:    Yingzhen Qu
                  <mailto:yingzhen.ietf@gmail.com>
        Author:    Acee Lindem
                  <mailto:acee.ietf@gmail.com>
        Author:    Stephane Litkowski
                  <mailto:slitkows.ietf@gmail.com>
        Author:    Jeff Tantsura
                  <mailto:jefftant.ietf@gmail.com>

       ";
     description
       "The YANG module augments the base MPLS model, and it is to
        provide support for different types of Maximum SID Depth (MSD).

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

        Copyright (c) 2024 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or

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        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;
        see the RFC itself for full legal notices.

        The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
        NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
        'MAY', and 'OPTIONAL' in this document are to be interpreted as
        described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
        they appear in all capitals, as shown here.";
     reference
       "RFC XXXX: A YANG Data Model for MPLS MSD.";

     revision 2024-01-24 {
       description
         "Initial Version";
       reference
         "RFC XXXX: A YANG Data Model for MPLS MSD.";
     }

     grouping msd-type-value {
       description
         "Grouping for MSD type and value.";
       leaf msd-type {
         type identityref {
           base iana-msd-types:msd-base-mpls;
         }
         mandatory true;
         description
           "MSD types. The MSD type is defined in IANA IGP
            MSD-Types registry.";
       }
       leaf msd-value {
         type uint8;
         mandatory true;
         description
           "MSD value, in the range of 0-255.";
       }
     }
     augment "/rt:routing/mpls:mpls" {
       description
         "This module augments MPLS data model (RFC 8960)
          with node MSD.";
       container node-msd {

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         config false;
         description
           "Maximum SID Depth (MSD) of a node.";
         list node-msds {
           key "msd-type";
           uses msd-type-value;
           description
             "List of different types of MSDs of the node. A type of
              Node MSD is the smallest same type link MSD supported by
              the node.";
         }
       }
     }

     augment "/rt:routing/mpls:mpls/mpls:interfaces/mpls:interface" {
       description
         "This module augments MPLS data model (RFC 8960)
          with link MSD.";
       container link-msd {
         config false;
         description
           "Maximum SID Depth (MSD) of an interface.";
         list link-msds {
           key "msd-type";
           uses msd-type-value;
           description
             "List of different types of MSDs on the link.";
         }
       }
     }
   }
   <CODE ENDS>

5.  Security Considerations

   The YANG modules specified in this document define a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

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

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   Some of the readable data nodes in the modules 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.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:

      /rt:routing/mpls:mpls/msd/node-msds

      /rt:routing/mpls:mpls/msd/link-msds

      Exposure of the node's maximum SID depth may be useful in mounting
      a Denial-of-Service (DoS) attack by sending packets to the node
      that the router can't process.

6.  IANA Considerations

   This document registers URIs in the IETF XML registry [RFC3688].
   Following the format in [RFC3688], the following registrations is
   requested to be made:

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

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

   This document registers the YANG modules in the YANG Module Names
   registry [RFC6020].

      name: iana-msd-types
      namespace: urn:ietf:params:xml:ns:yang:iana-msd-types
      prefix: iana-msd-types
      reference: RFC XXXX

      name: ietf-mpls-msd
      namespace: urn:ietf:params:xml:ns:yang:ietf-mpls-msd
      prefix: mpls-msd
      reference: RFC XXXX

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7.  Acknowledgements

   This document was produced using Marshall Rose's xml2rfc tool.

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

   We would like to thank Jan Lindblad, Tom Petch, and Susan Hares for
   their reviews and comments.

8.  References

8.1.  Normative References

   [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>.

   [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>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [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>.

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   [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>.

   [RFC8349]  Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for
              Routing Management (NMDA Version)", RFC 8349,
              DOI 10.17487/RFC8349, March 2018,
              <https://www.rfc-editor.org/info/rfc8349>.

   [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>.

   [RFC8476]  Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,
              "Signaling Maximum SID Depth (MSD) Using OSPF", RFC 8476,
              DOI 10.17487/RFC8476, December 2018,
              <https://www.rfc-editor.org/info/rfc8476>.

   [RFC8491]  Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg,
              "Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491,
              DOI 10.17487/RFC8491, November 2018,
              <https://www.rfc-editor.org/info/rfc8491>.

   [RFC8960]  Saad, T., Raza, K., Gandhi, R., Liu, X., and V. Beeram, "A
              YANG Data Model for MPLS Base", RFC 8960,
              DOI 10.17487/RFC8960, December 2020,
              <https://www.rfc-editor.org/info/rfc8960>.

8.2.  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>.

   [RFC8662]  Kini, S., Kompella, K., Sivabalan, S., Litkowski, S.,
              Shakir, R., and J. Tantsura, "Entropy Label for Source
              Packet Routing in Networking (SPRING) Tunnels", RFC 8662,
              DOI 10.17487/RFC8662, December 2019,
              <https://www.rfc-editor.org/info/rfc8662>.

Authors' Addresses

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

   Acee Lindem
   LabN Consulting, L.L.C.
   Email: acee.ietf@gmail.com

   Stephane Litkowski
   Cisco Systems
   Email: slitkows.ietf@gmail.com

   Jeff Tantsura
   Nvidia
   Email: jefftant.ietf@gmail.com

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