From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Oledzki Subject: Re: incorrect cksum with tcp/udp on lo with 2.6.20/2.6.21/2.6.22 Date: Tue, 2 Oct 2007 16:15:15 +0200 (CEST) Message-ID: References: <20070924013005.GB22054@gondor.apana.org.au> <20071002104033.GA30281@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="-187430788-95351712-1191334214=:3175" Cc: netdev@vger.kernel.org To: Herbert Xu Return-path: Received: from bizon.gios.gov.pl ([212.244.124.8]:47823 "EHLO bizon.gios.gov.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbXJBOPm (ORCPT ); Tue, 2 Oct 2007 10:15:42 -0400 In-Reply-To: <20071002104033.GA30281@gondor.apana.org.au> Content-ID: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---187430788-95351712-1191334214=:3175 Content-Type: TEXT/PLAIN; CHARSET=ISO-8859-2; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Content-ID: On Tue, 2 Oct 2007, Herbert Xu wrote: > On Mon, Sep 24, 2007 at 11:44:19AM +0200, Krzysztof Oledzki wrote: >> >> So, with DR mode, packet goes by the lo device (with bad checksum) and >> then get redirected outside. Unfortunately, when it leaves host it has b= ad >> checksum, too. :( > > Did you check this by taking a tcpdump on an external host? Yes. > Doing a local tcpdump doesn't work as tcpdump won't show the > correct checksum if checksum offload is enabled. Indeed, I'm aware about this. > If it's really sending a bogus checksum then it's a bug in > LVS. I'm not sure if we should call it a bug. LVS does not support such=20 configuration by default - it requires kernel patching. However, it worked= =20 with older kernels so that's why I asked if it is possible to force full=20 TCP/UDP checksum calculation? Thank you. Best regards, =09=09=09=09Krzysztof Ol=EAdzki ---187430788-95351712-1191334214=:3175--