A YANG Model for MPLS MSD

YANG is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF or RESTCONF . 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 , which itself augments , to provide operational state for various MSDs. 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 which defines basic MPLS configuration and state. The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) .

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 when, and only when, they appear in all capitals, as shown here.

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.

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

This document uses the graphical representation of data models per .

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

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

file "iana-msd-types@2024-05-28.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 "; 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). 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 2024-05-28 { 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; 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"; } }

]]>

 

    This document also defines a YANG module for MSD extensions 
       to MPLS base 
      model as defined in .
    
        
    
       file "ietf-mpls-msd@2024-05-28.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:   
     WG List:  

     Author:    Yingzhen Qu
               
     Author:    Acee Lindem
               
     Author:    Stephane Litkowski
               
     Author:    Jeff Tantsura
               
     
    ";
  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
     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 2024-05-28 {
    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-msds {
      config false;
      description
        "Maximum SID Depth (MSD) of a node.";
      list node-msd {
        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-msds {
      config false;
      description
        "Maximum SID Depth (MSD) of an interface.";
      list link-msd {
        key "msd-type";
        uses msd-type-value;
        description
          "List of different types of MSDs on the link.";
      }
    }
  }
}

      ]]>



  

    
    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  or
       RESTCONF . The lowest NETCONF layer is the secure transport
       layer, and the mandatory-to-implement secure transport is Secure Shell (SSH)
       . The lowest RESTCONF layer is HTTPS, and the
       mandatory-to-implement secure transport is TLS .

   The NETCONF Access Control Model (NACM)  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.
      

   

This document registers URIs in the IETF XML registry 
   .  Following the format in , 
   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 .
   
   
     
   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
    
   
   

    
      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.