From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evan Bigall Subject: Re: Problem with VLANs on tg3 NICs Date: Fri, 19 Jan 2007 08:09:18 -0500 Message-ID: <45B0C2FE.9050009@scalent.com> References: <45AFCB74.4030909@scalent.com> <8A87A9A84C201449A0C56B728ACF491E04F1AA@liverpoolst.ad.cl.cam.ac.uk> <45AFEAC8.7050904@scalent.com> <8A87A9A84C201449A0C56B728ACF491E04F1B6@liverpoolst.ad.cl.cam.ac.uk> <8A87A9A84C201449A0C56B728ACF491E04F1BF@liverpoolst.ad.cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <8A87A9A84C201449A0C56B728ACF491E04F1BF@liverpoolst.ad.cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Pratt Cc: xen-devel@lists.xensource.com, Nate Carlson List-Id: xen-devel@lists.xenproject.org >If its broadcasting all VLAN-tagged traffic to all ports that's >disastrous for performance. You'd be much better off setting up a >separate bridge for each VLAN. Alternatively, it might be worth looking >at The Linux Switching Appliance (LISA) project -- their bridge supports >VLAN trunks. > > I'd have to do a tcpdump to be sure but empirically I haven't noticed any performance problems (and these are nfs booted images). All I'm expecting of the bridge code is that it ignore the tag and deliver the packet by mac address as normal. Because all this works with other than the tg3 driver I'm confident the bridge code is doing what I expect. The problem is not with the bridge, the problem is with the tg3 driver. I believe that any network utility on top of the tg3 driver would have the same problem, as the tg3 driver is stripping the vlan tags before it passes them on. Evan