From owner-freebsd-net@FreeBSD.ORG Wed Dec 14 21:17:53 2011 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ED33E106567F for ; Wed, 14 Dec 2011 21:17:53 +0000 (UTC) (envelope-from ml@netfence.it) Received: from cp-out8.libero.it (cp-out8.libero.it [212.52.84.108]) by mx1.freebsd.org (Postfix) with ESMTP id 667F18FC15 for ; Wed, 14 Dec 2011 21:17:53 +0000 (UTC) X-CTCH-Spam: Unknown X-CTCH-RefID: str=0001.0A0B0205.4EE9127F.00E4,ss=1,re=0.000,fgs=0 X-libjamoibt: 1555 Received: from soth.ventu (151.41.159.94) by cp-out8.libero.it (8.5.133) id 4EBC059F04C319E7; Wed, 14 Dec 2011 22:17:51 +0100 Received: from alamar.ventu (alamar.ventu [10.1.2.18]) by soth.ventu (8.14.4/8.14.4) with ESMTP id pBELHfRe052906; Wed, 14 Dec 2011 22:17:41 +0100 (CET) (envelope-from ml@netfence.it) Message-ID: <4EE91275.3060808@netfence.it> Date: Wed, 14 Dec 2011 22:17:41 +0100 From: Andrea Venturoli User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; it-IT; rv:1.9.2.24) Gecko/20111207 Thunderbird/3.1.16 MIME-Version: 1.0 To: pyunyh@gmail.com References: <4EE8FA10.8090502@netfence.it> <20111214195918.GC11426@michelle.cdnetworks.com> In-Reply-To: <20111214195918.GC11426@michelle.cdnetworks.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.72 on 10.1.2.13 Cc: freebsd-net@freebsd.org Subject: Re: Intel 82550 Pro/100 Ethernet and TSO troubles 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: Wed, 14 Dec 2011 21:17:54 -0000 On 12/14/11 20:59, YongHyeon PYUN wrote: > AFAIK the firmware of controller has no known TSO issue so it > indicates a bug in driver. > What makes me wonder is ICMP ECHO packet should not be affected by > TSO and I have no clue at this moment. I wasn't talking about ICMP ECHO. What happened was: a) the client connected to my server, advertising a TCP MSS of X; b) my server started sending with packets larger than X (possibly it misinterpreted MSS size???); c) an ICMP packet arrived, asking my server to send packets no larger than Y (I guess it was ignored); d) my server kept resending the same (too big) packets; e) it eventually reduced packet size, but it was still larger than Y; ... Wireshark showed some wrong checksums (I believe on the ICMP packet, but I might remember wrong). Of course this made a bell ring and removing TSO solved everything. > (Here, I assume you've > captured packets on receiver side since bpf sees packets before > hardware computes checksum.) Yes, although I don't have them anymore. > If you have a reliable way that reproduces the issue, let me know. I can turn TSO on again, save the packets and send them to you. I just hope nothing changes on the Internet in between the server and the client. Let me know if you need/want this and I'll arrange in the next few days. bye & Thanks av.