From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH] bridge: flush forwarding table when device carrier off Date: Thu, 12 Oct 2006 17:30:33 -0400 Message-ID: <1160688633.5047.5.camel@jzny2> References: <20061012112431.0550b252@dxpl.pdx.osdl.net> <20061012201043.GA29253@gospo.rdu.redhat.com> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , "David S. Miller" , netdev@vger.kernel.org, bridge@osdl.org Return-path: Received: from mx02.cybersurf.com ([209.197.145.105]:19681 "EHLO mx02.cybersurf.com") by vger.kernel.org with ESMTP id S1751056AbWJLVag (ORCPT ); Thu, 12 Oct 2006 17:30:36 -0400 Received: from mail.cyberus.ca ([209.197.145.21]) by mx02.cybersurf.com with esmtp (Exim 4.30) id 1GY88W-0006M5-2e for netdev@vger.kernel.org; Thu, 12 Oct 2006 17:30:40 -0400 To: Andy Gospodarek In-Reply-To: <20061012201043.GA29253@gospo.rdu.redhat.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2006-12-10 at 16:10 -0400, Andy Gospodarek wrote: > On Thu, Oct 12, 2006 at 11:24:31AM -0700, Stephen Hemminger wrote: > > Flush the forwarding table when carrier is lost. This helps for > > availability because we don't want to forward to a downed device and > > new packets may come in on other links. > > > > Signed-off-by: Stephen Hemminger > > > > Stephen, > > This is an excellent idea I am on the other extreme - this is problematic if you have a large table already learnt. Agrevate that with an unstable link and it gets a lot worse. Both of which dont sound unrealistic in say a wireless AP. A more sane policy i have seen is a timer that flushes the table after a programmed period; this way you counter a flipflop-ing link. IOW, the best place is to have this in some user space daemon. If it has to be in the kernel, can you add a systcl to disable it? cheers, jamal