From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH 1/2] IPV4: remove addresses and routes when carrier is lost Date: Tue, 03 Jun 2008 18:44:44 +0200 Message-ID: <484574FC.5050004@trash.net> References: <20080602165249.52a467dc@extreme> <20080603150524.GA16165@csclub.uwaterloo.ca> <20080603085707.51fdabbb@speedy> <48456B62.8050909@trash.net> <20080603093159.36070e73@extreme> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , Lennart Sorensen , David Miller , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from stinky.trash.net ([213.144.137.162]:45615 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbYFCQoq (ORCPT ); Tue, 3 Jun 2008 12:44:46 -0400 In-Reply-To: <20080603093159.36070e73@extreme> Sender: netdev-owner@vger.kernel.org List-ID: Stephen Hemminger wrote: > On Tue, 03 Jun 2008 18:03:46 +0200 > Patrick McHardy wrote: > >> Stephen Hemminger wrote: >>> On Tue, 3 Jun 2008 11:05:24 -0400 >>> lsorense@csclub.uwaterloo.ca (Lennart Sorensen) wrote: >>> >>>> On Mon, Jun 02, 2008 at 04:52:49PM -0700, Stephen Hemminger wrote: >>>>> This patch adds a new configuration sysctl that causes link loss to clear >>>>> FIB state in the same way as admin down. This allows for routing daemons >>>>> like Quagga which have option to remove routes when carrier is lost. >>>>> >>>>> This has been a long standing problem with Quagga on Linux with complaints >>>>> on the developers list going back to 2004. Fixing it properly, so the routing >>>>> daemon manages the RIB, and the kernel manages the FIB, requires changes to >>>>> both parts. >>>> Does this cover only the local route for the interface, or all routes >>>> assigned staticly to the interface too? >>> The patch makes carrier down == interface down. So the same >>> behaviour as doing 'ip link set dev eth3 down' >> >> Can't the routing daemon simply ignore routes with a >> device that has no carrier? >> > > It does that, but the problem is that packets get routed in kernel > to interfaces without carrier, rather than being correctly rerouted > over alternate paths. I see, thanks for the explanation.