RFC 9304

Internet Engineering Task Force (IETF)                      M. Boucadair
Request for Comments: 9304                                  C. Jacquenet
Obsoletes: 8113                                                   Orange
Category: Standards Track                                   October 2022
ISSN: 2070-1721

Locator/ID Separation Protocol (LISP): Shared Extension Message and IANA
                  Registry for Packet Type Allocations


   This document specifies a Locator/ID Separation Protocol (LISP)
   shared message type for defining future extensions and conducting
   experiments without consuming a LISP Packet Type codepoint for each

   This document obsoletes RFC 8113.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at

Copyright Notice

   Copyright (c) 2022 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
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   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.  Requirements Language
   3.  LISP Shared Extension Message Type
   4.  Security Considerations
   5.  IANA Considerations
     5.1.  LISP Packet Types
     5.2.  Sub-Types
   6.  Changes from RFC 8113
   7.  Normative References

   Authors' Addresses

1.  Introduction

   The Locator/ID Separation Protocol (LISP) base specification,
   [RFC9301], defines a set of primitives that are identified with a
   packet type code.  Several extensions have been proposed to add more
   LISP functionalities.  It is expected that additional LISP extensions
   will be proposed in the future.

   The "LISP Packet Types" IANA registry (see Section 5) is used to ease
   the tracking of LISP message types.

   Because of the limited type space [RFC9301] and the need to conduct
   experiments to assess new LISP extensions, this document specifies a
   shared LISP extension message type and describes a procedure for
   registering LISP shared extension sub-types (see Section 3).
   Concretely, one single LISP message type code is dedicated to future
   LISP extensions; sub-types are used to uniquely identify a given LISP
   extension making use of the shared LISP extension message type.
   These identifiers are selected by the author(s) of the corresponding
   LISP specification that introduces a new LISP extension message type.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "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.

3.  LISP Shared Extension Message Type

   Figure 1 depicts the common format of the LISP shared extension
   message.  The type field MUST be set to 15 (see Section 5).

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     |Type=15|        Sub-type       |   extension-specific          |
     //                    extension-specific                       //
     //                                                             //

                Figure 1: LISP Shared Extension Message Type

   The 'Sub-type' field conveys a unique identifier that MUST be
   registered with IANA (see Section 5.2).

   The exact structure of the 'extension-specific' portion of the
   message is specified in the corresponding specification document.

4.  Security Considerations

   This document does not introduce any additional security issues other
   than those discussed in [RFC9301].

5.  IANA Considerations

5.1.  LISP Packet Types

   IANA has created a registry titled "LISP Packet Types", numbered

   Values can be assigned via Standards Action [RFC8126].  Documents
   that request for a new LISP Packet Type may indicate a preferred
   value in the corresponding IANA sections.

   IANA has replaced the reference to RFC 8113 with the RFC number of
   this document.

   Also, IANA has updated the table as follows:


   | Message                       | Code | Reference |
   | LISP Shared Extension Message | 15   | [RFC8113] |

                         Table 1


   | Message                       | Code | Reference |
   | LISP Shared Extension Message | 15   | RFC 9304  |

                         Table 2

5.2.  Sub-Types

   IANA has created the "LISP Shared Extension Message Type Sub-types"
   registry.  IANA has updated that registry by replacing the reference
   to RFC 8113 with the RFC number of this document.

   The values in the range 0-1023 are assigned via Standards Action.
   This range is provisioned to anticipate, in particular, the
   exhaustion of the LISP Packet Types.

   The values in the range 1024-4095 are assigned on a First Come, First
   Served (FCFS) basis.  The registration procedure is to provide IANA
   with the desired codepoint and a point of contact; providing a short
   description (together with an acronym, if relevant) of the foreseen
   usage of the extension message is also encouraged.

6.  Changes from RFC 8113

   The following changes were made from RFC 8113:

   *  Changed the status from Experimental to Standards Track.

   *  Indicated explicitly that the shared extension is used for two
      purposes: extend the type space and conduct experiments to assess
      new LISP extensions.

   *  Deleted pointers to some examples illustrating how the shared
      extension message is used to extend the LISP protocol.

   *  IANA has updated the "IANA LISP Packet Types" and "LISP Shared
      Extension Message Type Sub-types" registries to point to this
      document instead of RFC 8113.

7.  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,

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,

   [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>.

   [RFC9301]  Farinacci, D., Maino, F., Fuller, V., and A. Cabellos,
              Ed., "Locator/ID Separation Protocol (LISP) Control
              Plane", RFC 9301, DOI 10.17487/RFC9301, October 2022,


   This work is partly funded by ANR LISP-Lab project #ANR-13-INFR-

   Many thanks to Luigi Iannone, Dino Farinacci, and Alvaro Retana for
   the review.

   Thanks to Geoff Huston, Brian Carpenter, Barry Leiba, and Suresh
   Krishnan for the review.

Authors' Addresses

   Mohamed Boucadair
   35000 Rennes
   Email: mohamed.boucadair@orange.com

   Christian Jacquenet
   35000 Rennes
   Email: christian.jacquenet@orange.com