Internet Engineering Task Force (IETF) J. Snijders
Request for Comments: 8093 NTT
Category: Standards Track February 2017
ISSN: 2070-1721
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
Copyright (c) 2017 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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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Snijders Standards Track [Page 1]RFC 8093 Deprecation of Squatted BGP Path Attributes February 2017
Table of Contents
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.
Snijders Standards Track [Page 2]
RFC 8093 Deprecation of Squatted BGP Path Attributes February 2017
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
Snijders Standards Track [Page 3]
