Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262043AbUDPDPV (ORCPT ); Thu, 15 Apr 2004 23:15:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262109AbUDPDPV (ORCPT ); Thu, 15 Apr 2004 23:15:21 -0400 Received: from tantale.fifi.org ([216.27.190.146]:2448 "EHLO tantale.fifi.org") by vger.kernel.org with ESMTP id S262043AbUDPDPP (ORCPT ); Thu, 15 Apr 2004 23:15:15 -0400 To: Russell Miller Cc: linux-kernel@vger.kernel.org Subject: Re: udp traceroute dropping packets References: <200404152155.18724.rmiller@duskglow.com> Mail-Copies-To: nobody From: Philippe Troin Date: 15 Apr 2004 20:15:10 -0700 In-Reply-To: <200404152155.18724.rmiller@duskglow.com> Message-ID: <87brlstxz5.fsf@ceramic.fifi.org> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1551 Lines: 40 Russell Miller writes: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > I came across this archived linux-kernel message: > > http://www.uwsg.iu.edu/hypermail/linux/net/0007.2/0111.html > > I am having the exact same problem as is outlined there, from a post three > years ago. Here's a summary: > > "I think I've found a bug in UDP/ICMP code in the kernel using > traceroute. > > To reproduce: Launch traceroute -n to some Linux system nearby > really quickly 3 times in the row; localhost won't work, it has to go > through network. Quick response is crucial. I used systems w/ in > the same physical network and a few routers between (still < 5 ms > response). > > The effect: On third traceroute (or perhaps second/first, if you're quick > enough), ICMP port unreachable will not be sent to the UDP datagram. " > > I reproduced this on a redhat 8.0 machine running kernel 2.4.23. > Changing to the -I option of traceroute (to use ICMP) works > flawlessly. I'll be glad to provide more information if you need > it. Please CC, as I'm not subscribed. You're probably hitting the ICMP rate limit. Play with /proc/sys/net/ipv4/icmp_rate*. - increase /proc/sys/net/ipv4/icmp_ratelimit or - clear bit 3 in /proc/sys/net/ipv4/icmp_ratemask Phil. - 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/