From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: Problem with igb and vlans in 2.6.38-rc4 Date: Thu, 10 Feb 2011 12:51:57 -0800 Message-ID: <4D544FED.1000508@candelatech.com> References: <4D5426ED.7000801@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: netdev Return-path: Received: from mail.candelatech.com ([208.74.158.172]:56108 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710Ab1BJUv6 (ORCPT ); Thu, 10 Feb 2011 15:51:58 -0500 Received: from [192.168.100.195] (firewall.candelatech.com [70.89.124.249]) (authenticated bits=0) by ns3.lanforge.com (8.14.2/8.14.2) with ESMTP id p1AKpvG1022088 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 10 Feb 2011 12:51:57 -0800 In-Reply-To: <4D5426ED.7000801@candelatech.com> Sender: netdev-owner@vger.kernel.org List-ID: On 02/10/2011 09:57 AM, Ben Greear wrote: > > We have a user-space app that uses packet-sockets to grab and send > Ethernet frames (basically a user-space bridge). FYI: I'll post some patches for comment soon..seems I have it working now, just need to clean them up and eat lunch :) Thanks, Ben > > This has stopped working for VLANs unless we set the physical > port MTU to be vlan-MTU + 4 (ie, 1504 for standard MTU size vlan frames). > I think this started post 2.6.34 kernel..but not exactly sure at this > time. > > The test setup is essentially: > > client -- vlan 5 -- [ eth4 {software-bridge} eth3 ] -- vlan 5 -- server > > The software bridge machine has no VLANs enabled..it is supposed to just > read Ethernet frames from one port and xmit out the other. > > The bridge machine sees rx-length errors, and if only one port is > set to 1504, the other shows xmit errors (since it doesn't like sending > a frame 4 bytes larger than MTU probably). > > This used to work, and I'm hoping this change wasn't done on purpose. > > Thanks, > Ben > > -- Ben Greear Candela Technologies Inc http://www.candelatech.com