Internet                                                           Y. Qu
Internet-Draft                                                 Futurewei
Intended status: Standards Track                               A. Lindem
Expires: February 2, 2022                                   S. Litkowski
                                                           Cisco Systems
                                                             J. Tantsura
                                                                 Juniper
                                                          August 1, 2021


                       A YANG Model for MPLS MSD
                     draft-qu-mpls-mpls-msd-yang-01

Abstract

   This document defines a YANG data module 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 February 2, 2022.

Copyright Notice

   Copyright (c) 2021 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



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  YANG Module for MPLS MSD  . . . . . . . . . . . . . . . . . .   3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

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.

   This document defines a YANG data module augmenting the IETF MPLS
   YANG model [RFC8960], which itself augments [RFC8349], to provide
   operational state for various MSDs[RFC8662].

   The augmentation defined in this document requires support for the
   MPLS base model[RFC8960] which defines basic MPLS configuration and
   state.

   The YANG module in this document conforms 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].








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2.  YANG Module for MPLS MSD

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

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


   <CODE BEGINS> file "ietf-mpls-msd@2021-08-01.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-interfaces {
       prefix if;
       reference
         "RFC 8343: A YANG Data Model for Interface
                    Management (NMDA Version)";
     }

     import ietf-mpls {
       prefix mpls;
       reference "RFC 8960: A YANG Data Model for MPLS Base";
     }

     organization
       "IETF MPLS - MPLS Working Group";
     contact
       "WG Web:   <https://tools.ietf.org/wg/mpls/>
        WG List:  <mailto:mpls@ietf.org>



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

       ";
     description
       "The YANG module augments the base MPLS model, and it is to
        manage different types of MSDs.

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

        Copyright (c) 2021 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 Simplified 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: YANG Data Model for Segment Routing.";

     revision 2021-08-01 {
       description
         "Initial Version";
       reference "RFC XXXX: YANG Data Model for Segment Routing.";
     }

     identity msd-base-type {
       description
         "Base identity for MSD Type";



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     }

     identity base-mpls-msd {
       base msd-base-type;
       description
         "Base MPLS Imposition MSD.";
       reference
         "RFC 8491: Singling MSD using IS-IS.";
     }

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

     grouping max-sid-depth {
       description
         "Maximum SID Depth (MSD) grouping.";
       list node-msds {
         key "msd-type";
         leaf msd-type {
           type identityref {
           base msd-base-type;
           }
           description
             "MSD types";
         }
         leaf msd-value {
           type uint8;
           description
             "MSD value, in the range of 0-255.";
         }
         description
           "Node MSD is the smallest link MSD supported by
            the node.";
       }
       list link-msds {
         key "interface";
         leaf interface {
           type if:interface-ref;
           description
             "Reference to device interface.";
         }
         list link-msd {



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           key "msd-type";
           leaf msd-type {
             type identityref {
               base msd-base-type;
             }
             description
               "MSD type";
           }
           leaf msd-value {
             type uint8;
             description
               "MSD value, in the range of 0-255.";
           }
           description
             "List of link MSDs";
         }
         description
           "MSD supported by an individual interface.";
       }
     }

     augment "/rt:routing/mpls:mpls" {
       description
         "This module augments MPLS data model (RFC 8960)
          with MSD.";
       container msd {
         config false;
         description
           "Maximum SID Depth (MSD) operational state.";
         uses max-sid-depth;
       }
     }
   }
     <CODE ENDS>

3.  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-




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   configured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   There are a number of data nodes defined in the modules that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.

   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) attach by sending packets to the node
      that the router can't process.

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

5.  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.



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6.  References

6.1.  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>.

   [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>.







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   [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>.

6.2.  Informative References

   [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

   Yingzhen Qu
   Futurewei
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   EMail: yingzhen.qu@futurewei.com










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   Acee Lindem
   Cisco Systems
   301 Midenhall Way
   Cary, NC 27513

   EMail: acee@cisco.com


   Stephane Litkowski
   Cisco Systems

   EMail: slitkows.ietf@gmail.com


   Jeff Tantsura
   Juniper

   EMail: jefftant.ietf@gmail.com

































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