From owner-freebsd-questions@FreeBSD.ORG Thu Feb 16 04:13:45 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B646116A420 for ; Thu, 16 Feb 2006 04:13:45 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.88]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6F87743D49 for ; Thu, 16 Feb 2006 04:13:45 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from mac.com (smtpin08-en2 [10.13.10.153]) by smtpout.mac.com (Xserve/8.12.11/smtpout01/MantshX 4.0) with ESMTP id k1G4Dj40000291; Wed, 15 Feb 2006 20:13:45 -0800 (PST) Received: from [192.168.1.3] (pool-68-161-67-103.ny325.east.verizon.net [68.161.67.103]) (authenticated bits=0) by mac.com (Xserve/smtpin08/MantshX 4.0) with ESMTP id k1G4DgRC015186 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 15 Feb 2006 20:13:44 -0800 (PST) Message-ID: <43F3FBF6.1020501@mac.com> Date: Wed, 15 Feb 2006 23:13:42 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: Jerry Bell References: <43F3F70F.6040205@stelesys.com> In-Reply-To: <43F3F70F.6040205@stelesys.com> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=windows-1250 Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: Help with strange web server problem X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Feb 2006 04:13:45 -0000 Jerry Bell wrote: [ ... ] > I've done some more troubleshooting and some strange things have > appeared. First, the colo says there is NO proxy, and NO firewall in > front of this server. That's believable too, perhaps you simply have a NIC which is failing or is screwing up the packet checksums in some odd case. You would have to sniff the traffic from another machine (perhaps a sysadmin's laptop?) and grab the full packets ("-s 0" to tcpdump to be sure. Have you tried swapping NICs or adding a PCI NIC card? BTW: > 1671172334:1671172334(0) win 64512 This is not quite enough data to tell, but this looks like maybe you're seeing the IPv6 MSS of 1260 rather than what I get by default (1460?) under FreeBSD? Of course, it could just be a Windows client machine or something going through something like a VPN/PPTP tunnel which reduces the MTU...? What happens if you reduce your interface MTU to 1260? You ought to be looking for all traffic between your server and a test host, BTW, sometimes the ICMP traffic, if any, is important to understanding the issue. -- -Chuck