From owner-freebsd-net@FreeBSD.ORG Tue Jun 21 08:18:20 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 1E22F16A41C for ; Tue, 21 Jun 2005 08:18:20 +0000 (GMT) (envelope-from faasse@nlr.nl) Received: from mail-gateway.nlr.nl (mail-gateway.nlr.nl [137.17.162.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id A6EA243D1D for ; Tue, 21 Jun 2005 08:18:19 +0000 (GMT) (envelope-from faasse@nlr.nl) Received: from border.nlr.nl (border-qfe3 [137.17.162.1]) by mail-gateway.nlr.nl with SMTP id j5L8IHvZ5728086; (enveloppe sender address: faasse@nlr.nl); Tue, 21 Jun 2005 10:18:18 +0200 (CDT) Disclaimer: "The National Aerospace Laboratory NLR DOES NOT ACCEPT ANY FINANCIAL COMMITMENT derived from this message." Received: from pcea102a.nlr.nl (pcea102a.nlr.nl [137.17.4.108]) by spider.nlr.nl with ESMTP id j5L8IGPb22631234; Tue, 21 Jun 2005 10:18:16 +0200 (CDT) From: "p.r. faasse" Organization: nlr To: freebsd-net@freebsd.org Date: Tue, 21 Jun 2005 09:57:11 +0200 User-Agent: KMail/1.6.1 References: <344de287050617043219810b3@mail.gmail.com> <344de28705061706121fcf5040@mail.gmail.com> <344de2870506170641695a9385@mail.gmail.com> In-Reply-To: <344de2870506170641695a9385@mail.gmail.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200506210957.11858.faasse@nlr.nl> X-ESAFE-STATUS: Mail clean X-ESAFE-DETAILS: Clean Subject: Re: FreeBSD 5.4 802.1q and linux stalls 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: Tue, 21 Jun 2005 08:18:20 -0000 > > > On Fri, Jun 17, 2005 at 12:32:37PM +0100, Meno Abels wrote: > > > M> i have here a very strange problem which is in real a linux problem > > > M> but it is triggered by freebsd. I run a lan on which are linux 2.6.8(debian) and > > > M> freebsd 5.4 systems are connected to a unmanaged gigabit switch. All systems > > > M> uses this gigabit adapter: > > > M> Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet > > > M> Everything works fine until i do on one freebsd box the following: > > > M> ifconfig vlan0 172.20.21.1 netmask 255.255.255.0 vlan 2 vlandev re0 > > > M> i just do this, there is nowhere any configuration for 802.1q on any other > > > M> machine on this lan. > > > M> What is happen now the freebsd continues to run without any problem, but > > > M> all linuxs are stopping to understand any arp responses from a freebsd > > > M> nor an other linux. > > > M> So they stop to work over the time on this lan anymore. If I do > > > M> "ifconfig vlan0 unplumb" > > > M> it takes up to 10 minutes and the linux's are return to the working > > > M> status as before > > > M> the ifconfig vlan0... > > > M> I didn't not have any clue which network packet could cause these behavior in > > > M> a linux but there has to be one. Does anybody as any idea? I can only speak about a limilar problem i once saw on a completely different set-up (A load of WinXP machines..): We did UDP broadcast at a fixed rate (20 Hz), with > 1 MTU packet size data. One thing that can cause horrible disruption is a switch that 'cuts' these broadcast/multicast packets at a fragment boundary: each Lan card/the TCP stack will receive 'half' UDP packets, buffer them in the hope that the 'rest' of th UDP packet will arrive 'any moment now' and -in the long run- choke on them. We saw this with a 3Com Gigabit switch. After consulting 3Com we got the response that this was a 'feature' of their switch and 'dumped' the switch. The 'delayed' re-activation of the Lan's is something we also saw in this situation.