From owner-freebsd-stable@FreeBSD.ORG Fri Jan 15 19:33:22 2010 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 D34C7106566C for ; Fri, 15 Jan 2010 19:33:22 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: from mail-yx0-f171.google.com (mail-yx0-f171.google.com [209.85.210.171]) by mx1.freebsd.org (Postfix) with ESMTP id 890528FC13 for ; Fri, 15 Jan 2010 19:33:22 +0000 (UTC) Received: by yxe1 with SMTP id 1so734721yxe.3 for ; Fri, 15 Jan 2010 11:33:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:from:date:to:cc :subject:message-id:reply-to:references:mime-version:content-type :content-disposition:in-reply-to:user-agent; bh=SxhlmESmC67CZ/GDQ/YW0TYwjhUXU6ctYbVCdG/zi88=; b=Z/0WiqQF+7pXWMR+cq69MKOA5ShRgp33TaqkMZ6wLfh6qhTAepKhfO7dfe0iRlCnTU nKLk/nUoOPUQIBicN5yaKxpiFBmhN4xtfDD0XIlD9fJYgNRS4J6Oj2/QxcPHt/kNc+eK rS+LwO0Eq7tYZYVu6CAfWI1/JnnlDDNk54p5E= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:date:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=jN0fG4xoOJAXFlV50uAHNKlF16uzqL43P8u2jH5uywycdESdT9X2VFQdZceO4GJ+7B +Px+PT+TJlKSNEoM4lz5P5cz8FQbejBcZbgbCg1lwVL/xHNEpThdO6z3qu5KbSdeQD8/ 6lFspHCreAi7jkbozy51YSRhFcnWZlgx2AdlI= Received: by 10.150.31.9 with SMTP id e9mr1411422ybe.23.1263583996479; Fri, 15 Jan 2010 11:33:16 -0800 (PST) Received: from pyunyh@gmail.com ([174.35.1.224]) by mx.google.com with ESMTPS id 6sm879725ywd.52.2010.01.15.11.33.14 (version=TLSv1/SSLv3 cipher=RC4-MD5); Fri, 15 Jan 2010 11:33:15 -0800 (PST) Received: by pyunyh@gmail.com (sSMTP sendmail emulation); Fri, 15 Jan 2010 11:32:35 -0800 From: Pyun YongHyeon Date: Fri, 15 Jan 2010 11:32:35 -0800 To: alan bryan Message-ID: <20100115193235.GH1228@michelle.cdnetworks.com> References: <491716.58173.qm@web50503.mail.re2.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <491716.58173.qm@web50503.mail.re2.yahoo.com> User-Agent: Mutt/1.4.2.3i Cc: freebsd-stable@freebsd.org Subject: Re: General problems with checksums (txcsum/rxcsum) on FreeBSD 8.0? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jan 2010 19:33:22 -0000 On Fri, Jan 15, 2010 at 11:12:43AM -0800, alan bryan wrote: > I just read a different thread about problems with checksums on vge (and nfe in the replies). > > I'll just chime in here with some more information - I have a couple other message threads going about some weird high packet volumes on my new FreeBSD 8.0-Release NFS server. I thought it might be an issue with the igb driver so I put in a new card using em instead and got the exact same behavior. I'm currently sifting through a tcpdump in wireshark and there are all sorts of messages in there about checksums being incorrect - both TCP and UDP. This is for communications between this client machine (FreeBSD 7.0-Release) and any of the 8.0 machines I have. The packets going to non-8.0 machines (at least so far) appear to be fine. > > I'll defer to those who know more than I about the networking code, but is there perhaps an issue in general with the checksuming and not specific to one card or driver - is that even possible? That's now 4 different drivers all with various checksum problem reports. > > I'm going to be working on this all day today (and likely over the weekend) so if I can help by supplying information please let me know what you need. > If you are seeing bad checksum reported by tcpdump/wireshark for TX frames on checksum capable controller, it's normal. bpf(4) just sees TX frames before inserting checksum computed by hardware so tcpdump/wireshark reports invalid checksum. You can safely ignore that. If you want to verify whether sending host generated correct checksum, you should capture the frame on receive side. If tcpdump/ wireshark reports bad checksummed frame on received frames it's real bad checksummed frame.