From owner-freebsd-net@FreeBSD.ORG Fri Dec 30 05:01:55 2005 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 10BE816A41F; Fri, 30 Dec 2005 05:01:55 +0000 (GMT) (envelope-from julian@elischer.org) Received: from delight.idiom.com (outbound.idiom.com [216.240.47.197]) by mx1.FreeBSD.org (Postfix) with ESMTP id 854E243D55; Fri, 30 Dec 2005 05:01:52 +0000 (GMT) (envelope-from julian@elischer.org) Received: from idiom.com (idiom.com [216.240.32.1]) by delight.idiom.com (Postfix) with ESMTP id 06FE22297D8; Thu, 29 Dec 2005 21:01:52 -0800 (PST) Received: from [192.168.2.4] (home.elischer.org [216.240.48.38]) by idiom.com (8.12.11/8.12.11) with ESMTP id jBU51oa7016192; Thu, 29 Dec 2005 21:01:51 -0800 (PST) (envelope-from julian@elischer.org) Message-ID: <43B4BF3E.9070907@elischer.org> Date: Thu, 29 Dec 2005 21:01:50 -0800 From: Julian Elischer User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.12) Gecko/20051120 X-Accept-Language: en, hu MIME-Version: 1.0 To: Andre Oppermann References: <43B45D8A.7040609@elischer.org> <43B47A31.2CABFD7D@freebsd.org> In-Reply-To: <43B47A31.2CABFD7D@freebsd.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: forwarding icmp redirects. X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Dec 2005 05:01:55 -0000 Andre Oppermann wrote: > Julian Elischer wrote: > >>I know WE don't generate non local icmp redirects but I notice that we >>would forward them should someone else (malicious or not) generate them.. >>I think that we possibly should check for them in our forwarding code.. >>(of course you can stop them with the firewall but..) >> >>thoughts? > > > The job of the forwarding code is to forward packets with little to > no exceptions. Dropping certain types of ICMP packets is out of scope > for the forwarding code. The proper place is a firewall. > > IMHO we should disable emitting and acting upon ICMP redirects by default. I know many places that rely on them heavily.. please don't do that.. Cisco PIX doesn't generate them.. it makes that machine a pain in the **** to use in some situations. >