Internet DRAFT - draft-ietf-mpls-static-yang

draft-ietf-mpls-static-yang







MPLS Working Group                                               T. Saad
Internet-Draft                                         Cisco Systems Inc
Intended status: Standards Track                               R. Gandhi
Expires: 2 September 2024                            Cisco Systems, Inc.
                                                                  X. Liu
                                                          Volta Networks
                                                            V. P. Beeram
                                                        Juniper Networks
                                                              I. Bryskin
                                                              Individual
                                                            1 March 2024


                 A YANG Data Model for MPLS Static LSPs
                     draft-ietf-mpls-static-yang-14

Abstract

   This document contains the specification for the MPLS Static Label
   Switched Paths (LSPs) YANG model.  The model allows for the
   provisioning of static LSP(s) on Label Edge Router(s) LER(s) and
   Label Switched Router(s) LSR(s) devices along a LSP path without the
   dependency on any signaling protocol.  The MPLS Static LSP model
   augments the MPLS base YANG model with specific data to configure and
   manage MPLS Static LSP(s).

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 2 September 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.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Acronyms and Abbreviations  . . . . . . . . . . . . . . .   3
   2.  MPLS Static LSP Model . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Model Organization  . . . . . . . . . . . . . . . . . . .   3
     2.2.  Model Tree Diagram  . . . . . . . . . . . . . . . . . . .   4
     2.3.  Model Overview  . . . . . . . . . . . . . . . . . . . . .   6
     2.4.  Model YANG Module(s)  . . . . . . . . . . . . . . . . . .   6
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   5.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  12
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   This document describes a YANG [RFC7950] data model for configuring
   and managing the Multiprotocol Label Switching (MPLS) [RFC3031]
   Static LSPs.  The model allows the configuration of LER and LSR
   devices with the necessary MPLS cross-connects or bindings to realize
   an end-to-end LSP service.

   A static LSP is established by manually specifying incoming and
   outgoing MPLS label(s) and necessary forwarding information on each
   of the traversed LER and LSR devices (ingress, transit, or egress
   nodes) of the forwarding path.

   For example, on an ingress LER device, the model is used to associate
   a specific Forwarding Equivalence Class (FEC) of packets-- e.g.
   matching a specific IP prefix in a Virtual Routing or Forwarding
   (VRF) instance-- to an MPLS outgoing label imposition, next-hop(s)
   and respective outgoing interface(s) to forward the packet.  On an
   LSR device, the model is used to create a binding that swaps the
   incoming label with an outgoing label and forwards the packet on one
   or multiple egress path(s).  On an egress LER, it is used to create a



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   binding that decapsulates the incoming MPLS label and performs
   forwarding based on the inner MPLS label (if present) or IP
   forwarding in the packet.

   The MPLS Static LSP YANG model is contained in the module "ietf-mpls-
   static" and covers the basic features for the configuration and
   management of unidirectional MPLS Static LSP(s),

   The module "ietf-mpls-static" augments the MPLS Base YANG model
   defined in module "ietf-mpls" in [RFC8960].

1.1.  Terminology

   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.

   The terminology for describing YANG data models is found in
   [RFC7950].

1.2.  Acronyms and Abbreviations

      MPLS: Multiprotocol Label Switching

      LSP: Label Switched Path

      LSR: Label Switching Router

      LER: Label Edge Router

      FEC: Forwarding Equivalence Class

      NHLFE: Next Hop Label Forwarding Entry

      ILM: Incoming Label Map

2.  MPLS Static LSP Model

2.1.  Model Organization

   The base MPLS Static LSP model covers the core features with the
   minimal set of configuration parameters needed to manage and operate
   MPLS Static LSPs.






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     Routing module   +---------------+    v: import
                      | ietf-routing  |    o: augment
                      +---------------+
                          o
                          |
                          v
     MPLS base        +-----------+    v: import
     module           | ietf-mpls |    o: augment
                      +-----------+
                         o
                         |
                         v
                 +------------------+
     MPLS Static | ietf-mpls-static |
     LSP module  +------------------+

                Figure 1: Relationship between MPLS modules

2.2.  Model Tree Diagram

   The MPLS Static tree diagram as per [RFC8340] is shown in Figure 2.






























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   module: ietf-mpls-static

     augment /rt:routing/mpls:mpls:
       +--rw static-lsps
          +--rw static-lsp* [name]
             +--rw name           string
             +--rw operation?     mpls:mpls-operations-type
             +--rw in-segment
             |  +--rw fec
             |     +--rw (type)?
             |     |  +--:(ip-prefix)
             |     |  |  +--rw ip-prefix?        inet:ip-prefix
             |     |  +--:(mpls-label)
             |     |     +--rw incoming-label?   rt-types:mpls-label
             |     +--rw incoming-interface?     if:interface-ref
             +--rw out-segment
                +--rw (out-segment)?
                   +--:(nhlfe-single)
                   |  +--rw nhlfe-single
                   |     +--rw mpls-label-stack
                   |     |  +--rw entry* [id]
                   |     |     +--rw id               uint8
                   |     |     +--rw label?
                   |     |     |       rt-types:mpls-label
                   |     |     +--rw ttl?             uint8
                   |     |     +--rw traffic-class?   uint8
                   |     +--rw outgoing-interface?   if:interface-ref
                   +--:(nhlfe-multiple)
                      +--rw nhlfe-multiple
                         +--rw nhlfe* [index]
                            +--rw index                 string
                            +--rw backup-index?         string
                            +--rw loadshare?            uint16
                            +--rw role?                 nhlfe-role
                            +--rw mpls-label-stack
                            |  +--rw entry* [id]
                            |     +--rw id               uint8
                            |     +--rw label?
                            |     |       rt-types:mpls-label
                            |     +--rw ttl?             uint8
                            |     +--rw traffic-class?   uint8
                            +--rw outgoing-interface?   if:interface-ref

                   Figure 2: MPLS Static LSP tree diagram







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2.3.  Model Overview

   This document describes a YANG data model for the configuration and
   management of MPLS Static LSP(s) contained in a the YANG module
   'ietf-mpls-static'.

   The 'ietf-mpls-static' module contains the following high-level types
   and groupings:

   static-lsp-ref:

      A YANG reference type for a static LSP that can be used by data
      models to reference a configured static LSP.

   in-segment:

      A YANG grouping that describes parameters of an incoming class of
      FEC associated with a specific LSP as described in the MPLS
      architecture document [RFC3031].  The model allows the following
      types of traffic to be mapped onto the static LSP on an ingress
      LER:

       o Unlabeled traffic destined to a specific prefix
       o Labeled traffic arriving with a specific label

   out-segment:

      A YANG grouping that describes parameters for the forwarding
      path(s) and their associated attributes for an LSP.  The model
      allows for the following cases:

       o single forwarding path or NHLFE
       o multiple forwarding path(s) or NHLFE(s), each of which can
         serve a primary, backup or both role(s).

2.4.  Model YANG Module(s)

   Configuring LSPs through an LSR/LER involves the following steps:

   *  Enabling MPLS on MPLS capable interfaces.

   *  Configuring in-segments and out-segments on LER(s) and LSR(s)
      traversed by the LSP.

   *  Setting up the cross-connect per LSP to associate segments and/or
      to indicate connection origination and termination.

   *  Optionally specifying label stack actions.



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   *  Optionally specifying segment traffic parameters.

   The objects covered by this model are derived from the Incoming Label
   Map (ILM) and Next Hop Label Forwarding Entry (NHLFE) as specified in
   the MPLS architecture document [RFC3031].

   The ietf-mpls-static module imports the followinig modules:

   *  ietf-inet-types defined in [RFC6991]

   *  ietf-routing defined in [RFC8349]

   *  ietf-routing-types defined in [RFC8294]

   *  ietf-interfaces defined in [RFC8343]

   *  ietf-mpls defined in [RFC8960]

   The ietf-mpls-static module is shown below:

   <CODE BEGINS> file "ietf-mpls-static@2024-03-01.yang"
   module ietf-mpls-static {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-static";
     prefix "mpls-static";

     import ietf-mpls {
       prefix "mpls";
       reference "RFC8960: MPLS Base YANG Data Model";
     }

     import ietf-routing {
       prefix "rt";
       reference "RFC8349: A YANG Data Model for Routing Management";
     }

     import ietf-routing-types {
       prefix "rt-types";
       reference "RFC8294: Common YANG Data Types for the Routing Area";
     }

     import ietf-inet-types {
       prefix inet;
       reference "RFC6991: Common YANG Data Types";
     }

     import ietf-interfaces {
       prefix "if";



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       reference "RFC7223: A YANG Data Model for Interface Management";
     }

     organization "IETF MPLS Working Group";

     contact
       "WG Web:   <http://tools.ietf.org/wg/mpls/>

        WG List:  <mailto:mpls@ietf.org>

        Editor:   Tarek Saad
                  <mailto:tsaad.net@gmail.com>

        Editor:   Rakesh Gandhi
                  <mailto:rgandhi@cisco.com>

        Editor:   Xufeng Liu
                  <mailto: xufeng.liu.ietf@gmail.com>

        Editor:   Vishnu Pavan Beeram
                  <mailto:vbeeram@juniper.net>

        Editor:   Igor Bryskin
                  <mailto: Igor.Bryskin@huawei.com>";

     description
        "This YANG module augments the 'ietf-routing' module with basic
         configuration and operational state data for MPLS static
         The model fully conforms to the Network Management Datastore
         Architecture (NMDA).

         Copyright (c) 2018 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.";

     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.



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     revision "2024-03-01" {
       description
         "Latest revision of MPLS Static LSP YANG module";
       reference "RFC XXXX: A YANG Data Model for MPLS Static LSPs";
     }

     typedef static-lsp-ref {
       type leafref {
         path "/rt:routing/mpls:mpls/mpls-static:static-lsps/" +
              "mpls-static:static-lsp/mpls-static:name";
       }
       description
         "This type is used by data models that need to reference
          configured static LSP.";
     }

     grouping in-segment {
       description "In-segment grouping";
       container in-segment {
         description "MPLS incoming segment";
         container fec {
           description "Forwarding Equivalence Class grouping";
           choice type {
             description "FEC type choices";
             case ip-prefix {
               leaf ip-prefix {
                 type inet:ip-prefix;
                 description "An IP prefix";
               }
             }
             case mpls-label {
               leaf incoming-label {
                 type rt-types:mpls-label;
                 description "label value on the incoming packet";
               }
             }
           }
           leaf incoming-interface {
             type if:interface-ref;
             description
               "Optional incoming interface if FEC is restricted
                to traffic incoming on a specific interface";
           }
         }
       }
     }

     grouping out-segment {



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       description "Out-segment grouping";
       container out-segment {
         description "MPLS outgoing segment";
         choice out-segment {
           description "The MPLS out-segment type choice";
           case nhlfe-single {
             container nhlfe-single {
               description "Container for single NHLFE entry";
               uses mpls:nhlfe-single-contents;
               leaf outgoing-interface {
                 type if:interface-ref;
                 description
                   "The outgoing interface";
               }
             }
           }
           case nhlfe-multiple {
             container nhlfe-multiple {
               description "Container for multiple NHLFE entries";
               list nhlfe {
                 key index;
                 description "MPLS NHLFE entry";
                 uses mpls:nhlfe-multiple-contents;
                 leaf outgoing-interface {
                   type if:interface-ref;
                   description
                     "The outgoing interface";
                 }
               }
             }
           }
         }
       }
     }

     augment "/rt:routing/mpls:mpls" {
       description "Augmentations for MPLS Static LSPs";
       container static-lsps {
         description
           "Statically configured LSPs, without dynamic signaling";
         list static-lsp {
           key name;
           description "list of defined static LSPs";
           leaf name {
             type string;
             description "name to identify the LSP";
           }
           leaf operation {



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             type mpls:mpls-operations-type;
             description
               "The MPLS operation to be executed on the incoming
                packet";
           }
           uses in-segment;
           uses out-segment;
         }
       }
     }
   }
   <CODE ENDS>

3.  IANA Considerations

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

      URI: urn:ietf:params:xml:ns:yang:ietf-mpls-static
      Registrant Contact: The MPLS WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

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

      name:       ietf-mpls-static
      namespace:  urn:ietf:params:xml:ns:yang:ietf-mpls-static
      prefix:     ietf-mpls-static
      // RFC Ed.: replace XXXX with RFC number and remove this note
      reference:  RFCXXXX

4.  Security Considerations

   The YANG modules specified in this document define schemas 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 [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.





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   All nodes defined in this YANG module that are writable/creatable/
   deletable (i.e., config true, which is the default) 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.  These
   are the subtrees and data nodes and their sensitivity/vulnerability:

   o /ietf-routing:routing/ietf-mpls:mpls:/ietf-mpls:static-lsps: This
   entire subtree is related to security.

   An administrator needs to restrict write access to all configurable
   objects within this data model.

5.  Contributors

      Himanshu Shah
      Ciena
      email: hshah@ciena.com

      Kamran Raza
      Cisco Systems, Inc.
      email: skraza@cisco.com

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>.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031,
              DOI 10.17487/RFC3031, January 2001,
              <https://www.rfc-editor.org/info/rfc3031>.

   [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>.






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   [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>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [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>.

   [RFC8294]  Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger,
              "Common YANG Data Types for the Routing Area", RFC 8294,
              DOI 10.17487/RFC8294, December 2017,
              <https://www.rfc-editor.org/info/rfc8294>.

   [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>.

   [RFC8343]  Bjorklund, M., "A YANG Data Model for Interface
              Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
              <https://www.rfc-editor.org/info/rfc8343>.

   [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>.

   [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>.



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6.2.  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>.

Authors' Addresses

   Tarek Saad
   Cisco Systems Inc
   Email: tsaad.net@gmail.com


   Rakesh Gandhi
   Cisco Systems, Inc.
   Email: rgandhi@cisco.com


   Xufeng Liu
   Volta Networks
   Email: xufeng.liu.ietf@gmail.com


   Vishnu Pavan Beeram
   Juniper Networks
   Email: vbeeram@juniper.net


   Igor Bryskin
   Individual
   Email: i_bryskin@yahoo.com




















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