Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932476AbWCMVuN (ORCPT ); Mon, 13 Mar 2006 16:50:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932472AbWCMVuN (ORCPT ); Mon, 13 Mar 2006 16:50:13 -0500 Received: from palrel13.hp.com ([156.153.255.238]:14746 "EHLO palrel13.hp.com") by vger.kernel.org with ESMTP id S932471AbWCMVuL (ORCPT ); Mon, 13 Mar 2006 16:50:11 -0500 Message-ID: <4415E911.8090504@hp.com> Date: Mon, 13 Mar 2006 13:50:09 -0800 From: Rick Jones User-Agent: Mozilla/5.0 (X11; U; HP-UX 9000/785; en-US; rv:1.6) Gecko/20040304 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "linux-os (Dick Johnson)" Cc: Greg Scott , Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel , netdev@vger.kernel.org, Bart Samwel , Alan Cox , Simon Mackinlay Subject: Re: Router stops routing after changing MAC Address References: <925A849792280C4E80C5461017A4B8A20321F5@mail733.InfraSupportEtc.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1069 Lines: 24 > Anyway, if the device fails, you have > routers and hosts ARPing the interface, trying to establish a > route anyway. But only after what may be a much longer time than the customer is willing to accept or able to configure. I know of a number of HA situations where the "new" device is given the "old" MAC just to avoid that speicific situation of ARP caches not being updated except after quite some time. Not necessarily on the end-systems, the issue can be with intermediate devices (routers). And if one has to work with static ARP entries to deal (however imperfectly) with ARP poisioning or whatnot... Indeed, there is a large onus on the software doing the MAC override to make sure it does not break the required uniqueness. Just as if one were using locally administered MAC addresses. rick jones - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/