From owner-freebsd-stable@FreeBSD.ORG Thu Apr 3 18:45:07 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1FB85106566C for ; Thu, 3 Apr 2008 18:45:07 +0000 (UTC) (envelope-from bzeeb-lists@lists.zabbadoz.net) Received: from mail.cksoft.de (mail.cksoft.de [62.111.66.27]) by mx1.freebsd.org (Postfix) with ESMTP id B80748FC1E for ; Thu, 3 Apr 2008 18:45:06 +0000 (UTC) (envelope-from bzeeb-lists@lists.zabbadoz.net) Received: from localhost (amavis.str.cksoft.de [192.168.74.71]) by mail.cksoft.de (Postfix) with ESMTP id C884C41C703; Thu, 3 Apr 2008 20:45:05 +0200 (CEST) X-Virus-Scanned: amavisd-new at cksoft.de Received: from mail.cksoft.de ([62.111.66.27]) by localhost (amavis.str.cksoft.de [192.168.74.71]) (amavisd-new, port 10024) with ESMTP id YLbH4OR-S3gv; Thu, 3 Apr 2008 20:45:05 +0200 (CEST) Received: by mail.cksoft.de (Postfix, from userid 66) id 60F9E41C736; Thu, 3 Apr 2008 20:45:05 +0200 (CEST) Received: from maildrop.int.zabbadoz.net (maildrop.int.zabbadoz.net [10.111.66.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.int.zabbadoz.net (Postfix) with ESMTP id 4CDDB44487F; Thu, 3 Apr 2008 18:44:00 +0000 (UTC) Date: Thu, 3 Apr 2008 18:44:00 +0000 (UTC) From: "Bjoern A. Zeeb" X-X-Sender: bz@maildrop.int.zabbadoz.net To: Doug Hardie In-Reply-To: Message-ID: <20080403183952.G66744@maildrop.int.zabbadoz.net> References: X-OpenPGP-Key: 0x14003F198FEFA3E77207EE8D2B58B8F83CCF1842 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: FreeBSD Stable Subject: Re: Access Problems with 7.0 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Apr 2008 18:45:07 -0000 On Mon, 31 Mar 2008, Doug Hardie wrote: Hi, >> I recently upgraded 3 of my 5 servers to 7.0. Two of them are on new >> hardware and one is on hardware that used to run 6.2. Since then, 2 of my >> thousands of users are unable to access the servers running 7.0. They can >> access the server running 6.2 just fine. What happens is the server >> receives the SYN packet from the client properly and then responds with the >> SYN packet. Nothing more is heard from the client. The server sends a few >> duplicates of the SYN and then drops the connection. >> >> At this point I am not able to verify that the client receives the SYN. >> Neither of them has a clue about tcpdump. The packets look fine on this >> end (included later). Both are using Windows, including XP and Vista. I >> suspect they are receiving it and not accepting it for some reason. >> However, I don't really see anything that would cause that behavior in the >> packets. I can't reproduce the problem here. Every computer I can try >> works just fine. >> >> Here is one of the packet traces: >> >> 11:59:00.630414 00:00:0c:38:6f:e1 (oui Cisco) > 00:a0:cc:3e:87:9e (oui >> Unknown), ethertype IPv4 (0x0800), length 66: >> cpe-76-169-78-119.socal.res.rr.com.59025 > zool.lafn.org.8000: S >> 2779920420:2779920420(0) win 8192 >> >> 11:59:00.630634 00:a0:cc:3e:87:9e (oui Unknown) > 00:00:0c:38:6f:e1 (oui >> Cisco), ethertype IPv4 (0x0800), length 66: zool.lafn.org.8000 > >> cpe-76-169-78-119.socal.res.rr.com.59025: S >> 2480373222:2480373222(0) ack 2779920421 win 65535 > 3,sackOK,eol> >> >> 11:59:03.613011 00:00:0c:38:6f:e1 (oui Cisco) > 00:a0:cc:3e:87:9e (oui >> Unknown), ethertype IPv4 (0x0800), length 66: >> cpe-76-169-78-119.socal.res.rr.com.59025 > zool.lafn.org.8000: S >> 2779920420:2779920420(0) win 8192 >> >> 11:59:03.613194 00:a0:cc:3e:87:9e (oui Unknown) > 00:00:0c:38:6f:e1 (oui >> Cisco), ethertype IPv4 (0x0800), length 66: zool.lafn.org.8000 > >> cpe-76-169-78-119.socal.res.rr.com.59025: S 2480373222:2480373222(0) ack >> 2779920421 win 65535 >> > > Checking with the 6.2 server I see there are some differences in the TCP > options. 7.0 includes wscale 3 where 6.2 does not. Is there a way to > disable that feature using sysctl to see if thats the issue? You want to update to 7-STABLE which has the TCP fixes or you want to apply the following changes: 1.141.2.4 +10 -2 src/sys/netinet/tcp_output.c 1.157.2.2 +5 -2 src/sys/netinet/tcp_var.h In case you are not using MD5 that should be enough. Else see freebsd-net from the last 3 days for another patch. /bz -- Bjoern A. Zeeb bzeeb at Zabbadoz dot NeT Software is harder than hardware so better get it right the first time.