From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: Re: why are IPv6 addresses removed on link down Date: Tue, 13 Jan 2015 10:13:52 -0500 Message-ID: <20150113151352.GB28371@oracle.com> References: <54B4A7E4.7030301@gmail.com> <20150112231021.316648e3@urahara> <1421145346.13626.12.camel@redhat.com> <54B50873.4090907@miraclelinux.com> <54B50C71.7090007@miraclelinux.com> <1421152613.13626.24.camel@redhat.com> <54B53187.7080306@gmail.com> <20150113150048.GA28371@oracle.com> <1421161791.13626.33.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Ahern , YOSHIFUJI Hideaki , Stephen Hemminger , "netdev@vger.kernel.org" To: Hannes Frederic Sowa Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:34269 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751190AbbAMPOA (ORCPT ); Tue, 13 Jan 2015 10:14:00 -0500 Content-Disposition: inline In-Reply-To: <1421161791.13626.33.camel@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On (01/13/15 16:09), Hannes Frederic Sowa wrote: > > Yes, it does have something to do with it. But I didn't understand what > you meant by doing DAD on the interface-id. I have to dig up the RFCs for this, but I recall that, at one point, the specs assert that it is sufficient to verify that the interface-id (I think via DAD for the link-local address) is unique, and use that to infer uniqueness of all the other non-link-local addresses as well. I think later specs may have changed that, asserting that the correct, safe, proper thing to do is to separately DAD each address by itself. > If you look at the patches I just posted, only addresses which are in > link-local and not in permanent state will be flushed. > > I also need to do research on how to safely approach this, I don't know, > yet. > > Bye, > Hannes > >