RFC 9306 | Vendor-Specific LCAF | October 2022
Rodriguez-Natal, et al. | Experimental | [Page]

Stream:
  Internet Engineering Task Force (IETF)
RFC:
  9306
Updates:
  8060
Category:
  Experimental
Published:
  October 2022
ISSN:
  2070-1721
Authors:
  A. Rodriguez-Natal
  Cisco
  V. Ermagan
  Google, Inc.
  A. Smirnov
  Cisco
  V. Ashtaputre
  Cisco
  D. Farinacci
  lispers.net

# RFC 9306

# Vendor-Specific LISP Canonical Address Format (LCAF)

## Abstract

This document describes a new Locator/ID Separation Protocol (LISP) Canonical Address Format (LCAF), the Vendor-Specific LCAF. This LCAF enables organizations to have implementation-specific encodings for LCAF addresses. This document updates RFC 8060.¶

## Status of This Memo

This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation.¶

This document defines an Experimental Protocol for the Internet community. 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). Not all documents approved by the IESG are candidates for any level of Internet Standard; see 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 https://www.rfc-editor.org/info/rfc9306.¶

## 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 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.¶

## 1. Introduction

The LISP Canonical Address Format (LCAF) [RFC8060] defines the format and encoding for different address types that can be used on deployments of the Locator/ID Separation Protocol (LISP) [RFC9300] [RFC9301]. However, certain deployments require specific format encodings that may not be applicable outside of the use case for which they are defined. This document extends [RFC8060] to introduce a Vendor-Specific LCAF that defines how organizations can create LCAF addresses to be used only on particular LISP implementations. This document also updates [RFC8060] to specify the behavior when receiving unrecognized LCAF types.¶

## 2. Requirements Notation

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.¶

## 3. Unrecognized LCAF Types

[RFC8060] does not explain how an implementation should handle an unrecognized LCAF type. This document updates [RFC8060] to specify that any unrecognized LCAF type received in a LISP control plane message MUST be ignored. If all Locators are ignored, this is equivalent to a LISP control message with Locator Count = 0, as described in [RFC9301]. If an EID-Prefix only contains unrecognized LCAF types, the LISP control message MUST be dropped and the event MUST be logged. (Here, "EID" refers to Endpoint Identifier.)¶

## 4. Vendor-Specific LCAF

The Vendor-Specific LCAF relies on using the IEEE Organizationally Unique Identifier (OUI) [IEEE.802] to prevent collisions across vendors or organizations using the LCAF. The format of the Vendor-Specific LCAF is provided below.¶

     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           AFI = 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type = 255  |     Rsvd2     |            Length             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |      Rsvd3    |    Organizationally Unique Identifier (OUI)   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        Internal format...                     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 1: Vendor-Specific LCAF

The fields in the first 8 octets of the above Vendor-Specific LCAF are actually the fields defined in the general LCAF format specified in [RFC8060]. The Type field MUST be set 255, the value assigned by IANA to indicate that this is a Vendor-Specific LCAF; see Section 6. The Length field has to be set accordingly to the length of the internal format, plus the OUI, plus the Rsvd3 fields, as for [RFC8060]. The fields defined by the Vendor-Specific LCAF are as follows:¶

Rsvd3:
  This 8-bit field is reserved for future use. It MUST be set to 0 on transmit and MUST be ignored on receipt.¶
Organizationally Unique Identifier (OUI):
  This is a 24-bit field that carries an OUI or Company ID (CID) assigned by the IEEE Registration Authority (RA) as defined by the IEEE Std 802 [IEEE.802]¶
Internal format:
  This is a variable-length field that is left undefined on purpose. Each vendor or organization can define its own internal format(s) to use with the Vendor-Specific LCAF.¶

The Vendor-Specific LCAF type SHOULD NOT be used in deployments where different organizations interoperate. However, there may be cases where two (or more) organizations share a common deployment on which they explicitly and mutually agree to use a particular Vendor-Specific LCAF. In that case, the organizations involved need to carefully assess the interoperability concerns for that particular deployment. It is NOT RECOMMENDED to use an OUI not assigned to an organization.¶

If a LISP device receives a LISP message containing a Vendor-Specific LCAF with an OUI that it does not understand, it MUST drop the message and it SHOULD create a log message.¶

## 5. Security Considerations

This document enables organizations to define new LCAFs for their internal use. It is the responsibility of these organizations to properly assess the security implications of the formats they define. Security considerations from [RFC8060] apply to this document.¶

## 6. IANA Considerations

Following the guidelines of [RFC8126], IANA has assigned the following value for the Vendor-Specific LCAF from the "LISP Canonical Address Format (LCAF) Types" registry (defined in [RFC8060]):¶

Table 1: Vendor-Specific LCAF Assignment
Value | LISP LCAF Type Name | Reference
--- | --- | ---
255 | Vendor Specific | RFC 9306, Section 4

## 7. Normative References

[IEEE.802]
  IEEE, "IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture", DOI 10.1109/IEEESTD.2014.6847097, IEEE Std 802, July 2014, <https://ieeexplore.ieee.org/document/6847097>.
[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>.
[RFC8060]
  Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060, February 2017, <https://www.rfc-editor.org/info/rfc8060>.
[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, <https://www.rfc-editor.org/info/rfc8126>.
[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>.
[RFC9300]
  Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A. Cabellos, Ed., "The Locator/ID Separation Protocol (LISP)", RFC 9300, DOI 10.17487/RFC9300, October 2022, <https://www.rfc-editor.org/info/rfc9300>.
[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, <https://www.rfc-editor.org/info/rfc9301>.

## Acknowledgments

The authors would like to thank Joel Halpern, Luigi Iannone, and Alvaro Retana for their suggestions and guidance regarding this document.¶

## Authors' Addresses