From owner-freebsd-hackers Thu Oct 2 06:56:04 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id GAA26709 for hackers-outgoing; Thu, 2 Oct 1997 06:56:04 -0700 (PDT) Received: from inetfw.sonycsl.co.jp (inetfw.sonycsl.co.jp [203.137.129.4]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id GAA26674 for ; Thu, 2 Oct 1997 06:55:58 -0700 (PDT) Received: from hotaka.csl.sony.co.jp (hotaka.csl.sony.co.jp [43.27.98.57]) by inetfw.sonycsl.co.jp (8.8.5/3.5W) with ESMTP id WAA08474 for ; Thu, 2 Oct 1997 22:55:55 +0900 (JST) Received: from localhost (localhost [127.0.0.1]) by hotaka.csl.sony.co.jp (8.8.4/3.3W3) with ESMTP id WAA16171 for ; Thu, 2 Oct 1997 22:55:40 +0900 (JST) Message-Id: <199710021355.WAA16171@hotaka.csl.sony.co.jp> To: hackers@FreeBSD.ORG Subject: icmp sourcequench Date: Thu, 02 Oct 1997 22:55:39 +0900 From: Kenjiro Cho Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk I noticed that FreeBSD routers (and most other BSD based routers) send an ICMP_SOURCEQUENCH packet everytime a forwarding packet gets dropped, in other words, ip_forward receives ENOBUFS from ip_output. Isn't it better to comment out this part of the code? RFC1812 (Requirements for IP Version 4 Routers) says: 4.3.3.3 Source Quench A router SHOULD NOT originate ICMP Source Quench messages. As specified in Section [4.3.2], a router that does originate Source Quench messages MUST be able to limit the rate at which they are generated. DISCUSSION Research seems to suggest that Source Quench consumes network bandwidth but is an ineffective (and unfair) antidote to congestion. See, for example, [INTERNET:9] and [INTERNET:10]. Section [5.3.6] discusses the current thinking on how routers ought to deal with overload and network congestion. --kj --- Kenjiro Cho Sony Computer Science Laboratory Inc.