From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265764AbUGHBsM (ORCPT ); Wed, 7 Jul 2004 21:48:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265758AbUGHBrd (ORCPT ); Wed, 7 Jul 2004 21:47:33 -0400 Received: from mail.shareable.org ([81.29.64.88]:2481 "EHLO mail.shareable.org") by vger.kernel.org with ESMTP id S265722AbUGHBpc (ORCPT ); Wed, 7 Jul 2004 21:45:32 -0400 Date: Thu, 8 Jul 2004 02:44:43 +0100 From: Jamie Lokier To: bert hubert , "David S. Miller" , Stephen Hemminger , netdev@oss.sgi.com, linux-net@vger.kernel.org, linux-kernel@vger.kernel.org, ALESSANDRO.SUARDI@ORACLE.COM Subject: Re: preliminary conclusions regarding window size issues Message-ID: <20040708014443.GE17266@mail.shareable.org> References: <20040707232757.GA14471@outpost.ds9a.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040707232757.GA14471@outpost.ds9a.nl> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org bert hubert wrote: > Alessandro never sees these packets! ... > My current feeling is that some kind of QoS device is interfering, > and that the 'wscale gets stuffed' theory is wrong in this case. > > I recall that 'Packeteer' QoS devices try to mess with windows. It's a bit fiddly to arrange, but can you repeat the test and artificially lower the TTL for these packets which disappear? An iptable mangle rule would do the trick -- mangle the TTL only on packets which match this point in the trace. The idea is to reduce the TTL like traceroute does, so you can see which hop is causing these packets to disappear -- perhaps it'll stand out proudly as a QoS device which can be named, blamed and shamed. -- Jamie