From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [Bridge] Bridge & it's MAC address question Date: Fri, 15 Dec 2006 07:52:36 -0800 Message-ID: <20061215075236.321e6a07@localhost.localdomain> References: <200610301527.15018.dim@openvz.org> <20061030072837.51177183@localhost.localdomain> <20061215131908.GC11579@xi.wantstofly.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Dmitry Mishin , netdev@vger.kernel.org, bridge@osdl.org, devel@openvz.org Return-path: Received: from smtp.osdl.org ([65.172.181.25]:47775 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752762AbWLOPwm (ORCPT ); Fri, 15 Dec 2006 10:52:42 -0500 To: Lennert Buytenhek In-Reply-To: <20061215131908.GC11579@xi.wantstofly.org> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 15 Dec 2006 14:19:08 +0100 Lennert Buytenhek wrote: > On Mon, Oct 30, 2006 at 07:28:37AM -0800, Stephen Hemminger wrote: > > > > Could somebody explain, why bridge uses minimal MAC of the attached devices? > > > It makes this address instable, variable during bridge life-cycle, which is > > > not good for DHCP. For example, I want to attach multiple virtual devices to > > > one physical. Then, I need to make sure that after each virtual device > > > addition, bridge addr is not changed and still addr of the physical device. > > > Why not to use MAC of the first attached device? > > > > The bridge physical address is the minimum of all the attached devices. > > This is done because the STP standard requires it. You can reset it > > to be the same as any of the attached devices. This will not cause a > > problem unless using STP. > > You can in fact use any MAC address. The STP standard recommends using > the minimum address, as that is deterministic, and so it doesn't depend > on the order in which you enslave subdevices. So should restriction be lifted? Please update wiki page FAQ, or I'll do it