From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 8 Jan 2003 21:07:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 8 Jan 2003 21:07:50 -0500 Received: from mail5.intermedia.net ([206.40.48.155]:55057 "EHLO mail5.intermedia.net") by vger.kernel.org with ESMTP id ; Wed, 8 Jan 2003 21:07:47 -0500 Subject: Re: 2.4.19 ICMP redirects erroneously ignored From: Ranjeet Shetye To: timg@tpi.com Cc: Linux Kernel Mailing List In-Reply-To: <200301081852.05547.rtg@tim.rtg.net> References: <200301081852.05547.rtg@tim.rtg.net> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.5 Date: 08 Jan 2003 18:16:54 +0100 Message-Id: <1042046214.17783.7.camel@ranjeet-linux-1> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2003-01-09 at 02:52, Tim Gardner wrote: > I'm getting pounded by ICMP redirects from my Nortel router. The > setup is a SuSE 8.1 (2.4.19) standard client with fixed IP and netmask. > The client is configured with a default route. However, there are > several routers on the subnet that the default router knows about. > Hence, the reason that the Nortel router emits ICMP redirects > which my client steadfastly ignores. > > I've RTFM, read the kernel source, and checked the relevant settings > (/proc/sys/net/ipv4/conf/all/*). I find in /proc/net/rt_cache that there are > 2 entries, one of which is marked RTCF_REDIRECTED. > > Why isn't this redirected route being used? AFAIK, because that would mean that you are allowing another machine to manipulate your routing tables by simply using ICMP. How do you know that you can trust the other machine, in this case, the nortel router ? The problem is not of (missing) functionality, its about trusting the integrity of the source of the ICMP redirect. > > This seems like a problem that ought to be common to anyone that > has multiple routers on the same subnet. What am I missing? > > rtg > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Ranjeet Shetye Senior Software Engineer Zultys Technologies Ranjeet dot Shetye2 at Zultys dot com http://www.zultys.com/