Internet Engineering Task Force (IETF) F. Gont
Request for Comments: 6633 UTN-FRH / SI6 Networks
Updates: 792, 1122, 1812 May 2012
Category: Standards Track
ISSN: 2070-1721
Deprecation of ICMP Source Quench Messages
Abstract
This document formally deprecates the use of ICMP Source Quench
messages by transport protocols, formally updating RFC 792, RFC 1122,
and RFC 1812.
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 5741.
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/rfc6633.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Gont Standards Track [Page 1]
RFC 6633 Deprecation of ICMP Source Quench May 2012
Table of Contents
1. Introduction ....................................................2
2. ICMP Source Quench Messages .....................................3
3. Updating RFC 1122 ...............................................3
4. Updating RFC 1812 ...............................................4
5. Clarification for UDP, SCTP, and DCCP ...........................4
6. General Advice to Transport Protocols ...........................4
7. Recommendation Regarding RFC 1016 ...............................5
8. Security Considerations .........................................5
9. IANA Considerations .............................................5
10. Acknowledgements ...............................................5
11. References .....................................................6
11.1. Normative References ......................................6
11.2. Informative References ....................................7
Appendix A. Survey of Support of ICMP Source Quench in Some
Popular TCP/IP Implementations ........................8
1. Introduction
The ICMP specification [RFC0792] defined the ICMP Source Quench
message (type 4, code 0), which was meant as a mechanism for
congestion control. ICMP Source Quench has been known to be an
ineffective (and unfair) antidote for congestion, and generation of
ICMP Source Quench messages by routers has been formally deprecated
by [RFC1812] since 1995. However, reaction to ICMP Source Quench
messages in transport protocols has never been formally deprecated.
This document formally deprecates reaction to ICMP Source Quench
messages by transport protocols such as TCP [RFC0793], formally
updating [RFC0792], [RFC1122], and [RFC1812]. Additionally, it
provides a recommendation against the implementation of [RFC1016].
The rationale for these specification updates is as follows:
o Processing of ICMP Source Quench messages by routers has been
deprecated for nearly 17 years [RFC1812].
o Virtually all popular host implementations have removed support
for ICMP Source Quench messages since (at least) 2005 [RFC5927].
o Widespread deployment of ICMP filtering makes it impossible to
rely on ICMP Source Quench messages for congestion control.
o The IETF has moved away from ICMP Source Quench messages for
congestion control (e.g., note the development of Explicit
Congestion Notification (ECN) [RFC3168] and the fact that ICMPv6
[RFC4443] does not even specify a Source Quench message).
Gont Standards Track [Page 2]
RFC 6633 Deprecation of ICMP Source Quench May 2012
ICMP Source Quench messages are not normally seen in the
deployed Internet and were considered rare at least as far back
datatracker.ietf.org