From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gabriel Beddingfield Subject: Re: Miscalculated TCP ACK ? Date: Mon, 22 Aug 2011 19:41:45 -0500 Message-ID: <4E52F749.4000204@gmail.com> References: <1314031128.2307.110.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <1314038973.3777.0.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE To: netdev@vger.kernel.org Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:53815 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752183Ab1HWAls (ORCPT ); Mon, 22 Aug 2011 20:41:48 -0400 Received: by yxj19 with SMTP id 19so3920332yxj.19 for ; Mon, 22 Aug 2011 17:41:47 -0700 (PDT) In-Reply-To: <1314038973.3777.0.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On 08/22/2011 01:49 PM, Eric Dumazet wrote: > Le lundi 22 ao=C3=BBt 2011 =C3=A0 13:05 -0500, Gabriel Beddingfield a= =C3=A9crit : >> On Mon, Aug 22, 2011 at 12:19 PM, Daniel Baluta wrote: >>>>> It appears to me that the ACK is off-by-one (should have been 276= 76). >>>>> The server replies again with retransmissions. This is with seve= ral >>>>> kernel versions on local machines, ranging from 2.6.31 to 2.6.38. >>> >>>> Not a bug if frame carried a FIN >> >> The server packet had the FIN bit set. >> > > then its fine. Thank you! >> I clipped the conversation to the vicinity of the problem. > > This sounds as a TSO bug, maybe driver/NIC related > > What is the NIC/driver used on your server ? New news: If I remove my router (Linksys WRTU54G-TM), the problem goes= =20 away. Thank you guys for your helpful insights. :-) -gabriel