Internet Engineering Task Force (IETF)
Request for Comments: 8093
Category: Standards Track
ISSN: 2070-1721

J. Snijders
NTT
February 2017

Deprecation of BGP Path Attribute

Values 30, 31, 129, 241, 242, and 243

Abstract

This document requests IANA to mark BGP path attribute values 30, 31, 129, 241, 242, and 243 as "Deprecated".

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 http://www.rfc-editor.org/info/rfc8093.

Copyright Notice

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   2
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   2
   4.  Informative References  . . . . . . . . . . . . . . . . . . .   3
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   3
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   3

1. Introduction

It has been discovered that certain BGP Path Attribute values have been used in BGP implementations that have been deployed in the wild while not being assigned by IANA for such usage. Unregistered usage of BGP Path Attribute values can lead to deployment problems for new technologies.

The use of these unregistered values was noticed when the BGP Large Communities attribute [RFC8092] was initially assigned value 30 by IANA. It was subsequently discovered that a widely deployed BGP-4 [RFC4271] implementation had released code that used path attribute 30 and that applied a "Treat-as-withdraw" [RFC7606] strategy to routes containing a valid Large Community attribute, since it was expecting a different data structure. Because these routes were dropped, early adopters of Large Communities were unreachable from parts of the Internet. As a workaround, a new Early IANA Allocation was requested.

The squatting of values 30, 31, 129, 241, 242, and 243 has been confirmed by the involved vendors or through source code review.

2. IANA Considerations

IANA has marked values 30, 31, 129, 241, 242, and 243 as "Deprecated" in the "BGP Path Attributes" subregistry under the "Border Gateway Protocol (BGP) Parameters" registry. The marking "Deprecated" means "use is not recommended" ([IANA-GUIDELINES]).

3. Security Considerations

There are no meaningful security consequences arising from this registry update.

4. Informative References

[IANA-GUIDELINES]

              Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", Work in
              Progress, draft-leiba-cotton-iana-5226bis-18, September
              2016.
   
   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <http://www.rfc-editor.org/info/rfc4271>.
   
   [RFC7606]  Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
              Patel, "Revised Error Handling for BGP UPDATE Messages",
              RFC 7606, DOI 10.17487/RFC7606, August 2015,
              <http://www.rfc-editor.org/info/rfc7606>.
   
   [RFC8092]  Heitz, J., Ed., Snijders, J., Ed., Patel, K., Bagdonas,
              I., and N. Hilliard, "BGP Large Communities Attribute",
              RFC 8092, DOI 10.17487/RFC8092, February 2017,
              <http://www.rfc-editor.org/info/rfc8092>.

Acknowledgements

The author would like to gratefully acknowledge Marlien Vijfhuizen who helped discover the squatting of value 30, and Nick Hilliard for editorial feedback.

Author's Address

   Job Snijders
   NTT Communications
   Theodorus Majofskistraat 100
   Amsterdam  1065 SZ
   The Netherlands

Email:

          job@ntt.net