From mboxrd@z Thu Jan 1 00:00:00 1970 From: Toyo Abe Subject: Re: [IPV6] ADDRCONF: Defer dad for global address until dad for linklocal is completed. Date: Tue, 20 May 2008 21:35:05 +0900 Message-ID: <4832C579.2040800@miraclelinux.com> References: <48324792.5070309@miraclelinux.com> <20080520.173353.128167700.yoshfuji@linux-ipv6.org> <4832C3CC.5070609@miraclelinux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: davem@davemloft.net, netdev@vger.kernel.org To: =?UTF-8?B?WU9TSElGVUpJIEhpZGVha2kgLyDlkInol6Toi7HmmI4=?= Return-path: Received: from ns.miraclelinux.com ([219.118.163.66]:12440 "EHLO mail.miraclelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765900AbYETMfH (ORCPT ); Tue, 20 May 2008 08:35:07 -0400 In-Reply-To: <4832C3CC.5070609@miraclelinux.com> Sender: netdev-owner@vger.kernel.org List-ID: Sorry for lack of explanation. > But then, many other test scenarios in TAHI test suite went to FAIL.= =20 It was because > the tester node send RA with prefix option to the host right after i= t=20 receives DAD NS > from the host, which is obviously in autoconfiguration process for=20 linklocal address. And the tester node never accepts RS(es) from the host after sending th= e=20 RA. The tester node determine FAIL unless it doesn't receive DAD NS for corresponding=20 global address from the host. -toyo Toyo Abe wrote: > Yoshifuji-san, > > Thanks for your response. > > > Why don't we just ignore RA until DAD for link-local > > address has been successfully completed? > I was also thinking so. And I tried it at first. > But then, many other test scenarios in TAHI test suite went to FAIL.=20 > It was because > the tester node send RA with prefix option to the host right after it= =20 > receives DAD NS > from the host, which is obviously in autoconfiguration process for=20 > linklocal address. > > Besides, RFC4862 section 4(protocol overview) says; > --- > To speed the autoconfiguration process, a host may generate its link- > local address (and verify its uniqueness) in parallel with waiting > for a Router Advertisement. Because a router may delay responding to > a Router Solicitation for a few seconds, the total time needed to > complete autoconfiguration can be significantly longer if the two > steps are done serially. > --- > > The text indicates that a host *may* accept RA including prefix=20 > option even before > completion of DAD for linklocal address. > Since current addrconf code actually accepts RA including prefix=20 > option while DAD for > linklocal address is processing, changes of the behaviour looks like = a=20 > degradation for me. > Hence, I chose to accept RA at that moment and defer sending DAD NS=20 > for global addresses. > > Thanks, > -toyo > > YOSHIFUJI Hideaki / =E5=90=89=E8=97=A4=E8=8B=B1=E6=98=8E wrote: >> In article <48324792.5070309@miraclelinux.com> (at Tue, 20 May 2008=20 >> 12:37:54 +0900), Toyo Abe says: >> >>> This patch fixes the problem by deferring DAD initiation for global= =20 >>> address until >>> DAD for linklocal address is completed. Now the failed test=20 >>> scenarios noted above >>> are all passed. >> >> Why don't we just ignore RA until DAD for link-local >> address has been successfully completed? >> >> --yoshfuji >> >> > >