Internet-Draft MPLS MSD YANG October 2022
Qu, et al. Expires 23 April 2023 [Page]
Workgroup:
Internet
Internet-Draft:
draft-ietf-mpls-msd-yang-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
Y. Qu
Futurewei
A. Lindem
Cisco Systems
S. Litkowski
Cisco Systems
J. Tantsura
Microsoft

A YANG Model for MPLS MSD

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 23 April 2023.

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].

This document defines a YANG data model augmenting the IETF MPLS YANG model [RFC8960], which itself augments [RFC8349], to provide operational state for various MSDs[RFC8662]. The model 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 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", "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. 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 node-msd
       +--ro node-msds* []
          +--ro msd-type?    identityref
          +--ro msd-value?   uint8
  augment /rt:routing/mpls:mpls/mpls:interfaces/mpls:interface:
    +--ro link-msd
       +--ro link-msds* []
          +--ro msd-type?    identityref
          +--ro msd-value?   uint8

<CODE BEGINS> file "ietf-mpls-msd@2022-10-12.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";
  }

  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.qu@futurewei.com>
     Author:    Acee Lindem
               <mailto:acee@cisco.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) 2022 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;
     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 MPLS MSD.";

  revision 2022-10-12 {
    description
      "Initial Version";
    reference "RFC XXXX: YANG Data Model for MPLS MSD.";
  }

  identity msd-base-type {
    description
      "Base identity for Maximum SID Depth (MSD) Type";
  }

  identity msd-mpls {
    base msd-base-type;
    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.";
  }

  identity msd-erld {
    base msd-base-type;
    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";
  }

  augment "/rt:routing/mpls:mpls" {
    description
      "This module augments MPLS data model (RFC 8960)
       with node MSD.";
    container node-msd {
      config false;
      description
        "Maximum SID Depth (MSD) of a node.";
      list node-msds {
        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
          "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 {
        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 different types of MSDs on the link.";
      }
    }
  }
}

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

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.

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.

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, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <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, , <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, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242]
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <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, , <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, , <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, , <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, , <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, , <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, , <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, , <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, , <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, , <https://www.rfc-editor.org/info/rfc8662>.

Authors' Addresses

Yingzhen Qu
Futurewei
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Acee Lindem
Cisco Systems
301 Midenhall Way
Cary, NC 27513
Stephane Litkowski
Cisco Systems
Jeff Tantsura
Microsoft