From owner-freebsd-current@FreeBSD.ORG Fri Feb 23 07:17:34 2007 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id EFAFD16A400; Fri, 23 Feb 2007 07:17:34 +0000 (UTC) (envelope-from andy@siliconlandmark.com) Received: from lexi.siliconlandmark.com (lexi.siliconlandmark.com [209.69.98.4]) by mx1.freebsd.org (Postfix) with ESMTP id 9621613C46B; Fri, 23 Feb 2007 07:17:32 +0000 (UTC) (envelope-from andy@siliconlandmark.com) Received: from [10.0.1.5] (cpe-24-33-245-212.twmi.res.rr.com [24.33.245.212]) by lexi.siliconlandmark.com (8.13.8/8.13.3) with ESMTP id l1N7HFvr078954; Fri, 23 Feb 2007 02:17:15 -0500 (EST) (envelope-from andy@siliconlandmark.com) In-Reply-To: <45DC679A.9030304@freebsd.org> References: <17850.13146.266196.499166@grasshopper.cs.duke.edu> <2FE2BC67-A829-4BF9-B606-65DE1393E8DE@siliconlandmark.com> <17883.19584.99616.808623@grasshopper.cs.duke.edu> <45DC679A.9030304@freebsd.org> Mime-Version: 1.0 (Apple Message framework v752.3) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <566BDEAE-5E29-4B35-AF30-37DBADD19FBE@siliconlandmark.com> Content-Transfer-Encoding: 7bit From: Andre Guibert de Bruet Date: Fri, 23 Feb 2007 02:17:15 -0500 To: Andre Oppermann X-Mailer: Apple Mail (2.752.3) X-Virus-Scanned: ClamAV 0.88.7/2631/Thu Feb 22 16:33:11 2007 on lexi.siliconlandmark.com X-Virus-Status: Clean X-Information: Please contact the ISP for more information X-SL-MailScanner: Not scanned: please contact your Internet E-Mail Service Provider for details X-SL-SpamCheck: not spam, SpamAssassin (not cached, score=0.047, required 6, AWL 0.60, BAYES_00 -2.60, RCVD_IN_SORBS_DUL 2.05, SPF_PASS -0.00) X-MailScanner-From: andy@siliconlandmark.com Cc: Andrew Gallatin , current@freebsd.org Subject: Re: excessive TCP duplicate acks? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Feb 2007 07:17:35 -0000 On Feb 21, 2007, at 10:39 AM, Andre Oppermann wrote: > Andre Guibert de Bruet wrote: >> On Feb 20, 2007, at 2:31 PM, Andrew Gallatin wrote: >>> Thanks for reporting this. I'm glad I'm not the only one who is >>> seeing this! >> I discovered this while testing out a new multi-homed bonded-T1 >> installation. I was wondering why I was getting no more than >> ~170KB/ s. So far, here are the data points that I have gathered: >> - It affects more than one type of NIC (em0). >> - It happens regardless of hardware checksum enabled status. >> - It happens independent of IP aliasing. >> - I tested GENERIC as of Feb 19 and it is affected. >> - A kernel from December 15th, 2006 exhibits this problem. >> - The affected system is connected to a Linksys 24-port unmanaged >> gigabit switch (I have the exact same hardware working just fine >> with 5.5-STABLE on the same switch). > > Today I finally got some spare time and tried to track this down. > However > there is no obvious smoking gun to be seen. I'll dig further. Andre, Just as a followup to my off-list email: I have since come across kern/102653. Though my setup uses stateful inspection rules exclusively, the problem still persists with "allow ip from any to any" as the single rule in ipfw. I have a pcap of the traffic patterns that I am seeing, at http://siliconlandmark.com/staff/andre/ files/7-current_dupacks.pcap (2.3MB - This pcap was made with the single allow any to any rule). Andy /* Andre Guibert de Bruet * 6f43 6564 7020 656f 2e74 4220 7469 6a20 */ /* Code poet / Sysadmin * 636f 656b 2e79 5320 7379 6461 696d 2e6e */ /* GSM: +1 734 846 8758 * 5520 494e 2058 6c73 7565 6874 002e 0000 */ /* WWW: siliconlandmark.com * C/C++, Java, Perl, PHP, SQL, XHTML, XML */