From mboxrd@z Thu Jan 1 00:00:00 1970 From: "=?iso-8859-1?q?R=E9mi?= Denis-Courmont" Subject: Re: [PATCH] ipv6: address preservation on link down Date: Fri, 9 Jan 2009 10:02:06 +0200 Message-ID: <200901091002.07224.remi.denis-courmont@nokia.com> References: <20090108135614.23aed603@extreme> <20090108.140339.00980764.davem@davemloft.net> <20090108171415.1d282743@extreme> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , yoshfuji@linux-ipv6.org, netdev@vger.kernel.org To: "ext Stephen Hemminger" Return-path: Received: from smtp.nokia.com ([192.100.122.230]:29724 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751492AbZAIICu convert rfc822-to-8bit (ORCPT ); Fri, 9 Jan 2009 03:02:50 -0500 In-Reply-To: <20090108171415.1d282743@extreme> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Friday 09 January 2009 03:14:15 ext Stephen Hemminger, you wrote: > When an interface goes down, IPV6 deletes all addresses unlike IPV4. = This > is a problem since it can break routing protocols and other applicati= ons. > It looks like this was done to handle DAD, but is a big stick solutio= n when > other code is possible. > > The following patch changes the behaviour to delete link local addres= ses > but keep all configured addresses and restart DAD when interface come= s back > up. Let alone the backward compatibility problem for a minute. I have two _= other_=20 problems with this: 1/ If DAD should fail when the interface is brought back up, wouldn't a= ll the=20 EAU-64 autoconfigured address become invalid, rather than just the link= -local=20 one? 2/ In some case the link-local address is assigned by userland, no diff= erent=20 from the other ones. At least miredo is behaving this way. --=20 R=E9mi Denis-Courmont Maemo Software, Nokia Devices R&D