From owner-freebsd-stable@FreeBSD.ORG Tue May 12 18:35:03 2009 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 A7B5A106566B for ; Tue, 12 May 2009 18:35:03 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id 63A2C8FC17 for ; Tue, 12 May 2009 18:35:02 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from root by ciao.gmane.org with local (Exim 4.43) id 1M3wog-00059E-HC for freebsd-stable@freebsd.org; Tue, 12 May 2009 18:35:02 +0000 Received: from cpe-65-189-186-49.columbus.res.rr.com ([65.189.186.49]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 12 May 2009 18:35:02 +0000 Received: from dsamms by cpe-65-189-186-49.columbus.res.rr.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 12 May 2009 18:35:02 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-stable@freebsd.org From: David Samms Date: Tue, 12 May 2009 13:41:22 -0400 Lines: 30 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: cpe-65-189-186-49.columbus.res.rr.com User-Agent: Thunderbird 2.0.0.21 (X11/20090429) Sender: news Subject: TCP differences in 7.2 vs 7.1 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: Tue, 12 May 2009 18:35:03 -0000 After upgrading to 7.2 (amd64) some customers complained of very poor bandwidth. Upon investigation all the effected customers were ATT DSL clients located all over the USA, not in a single city, nor were other ISPs effected. The server is a Supermicro with dual (quad core) processors with a single Intel fxp network card on a 100mbit connection. Kernel is GENERIC for both 7.1_release and 7.2_release. Normally a client can max out their download connection, but for ATT DSL customers the transfer rate would be about 5-10KB/s even though the server and client where both idle. Repeated tests were done, from multiple clients in different geographical locations. The problem manifested itself regardless of whether ftp, http, smtp, pop, or scp was used, and regardless of the OS of the client. Believing it to be a routing issue we changed the route and even changed the local router the server is connected to so that a different NIC port would be used to talk to ATT DSL customers, but no change in performance. Turns out it is somehow related to differences in FreeBSD 7.1 and 7.2. If I boot the same server with 7.1, all clients work as you would expect. But, if 7.2 is used all clients with the exception of ATT DSL clients would work normally, ATT customers would be limited to 5-10KB/s. I have no reason to believe there is anything wrong with the ATT DSL network, it just happen to be effected by whatever causes the problem. Any theories? A special thanks to cybercon.com tech support for being so helpful. If you need a data center, they have good tech support.