From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [Bugme-new] [Bug 28512] New: IPv6 SLAAC address preferred over static one as source address Date: Tue, 29 Mar 2011 17:20:00 -0700 (PDT) Message-ID: <20110329.172000.102543782.davem@davemloft.net> References: <20110207152048.22c51184.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, ghen@telenet.be To: akpm@linux-foundation.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:45940 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751605Ab1C3AUi (ORCPT ); Tue, 29 Mar 2011 20:20:38 -0400 In-Reply-To: <20110207152048.22c51184.akpm@linux-foundation.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Andrew Morton Date: Mon, 7 Feb 2011 15:20:48 -0800 >> SLAAC addresses will have a limited preferred lifetime (as defined by the >> router), static addresses will usually have an unlimited preferred lifetime >> (0). So it makes a lot of sense to take this preferred lifetime into account >> for source address selection (how is it otherwise "preferred"?). This is debatable. One could just as easily say that an address with a shorter preferred lifetime has been revalidated more recently, and therefore is more likely to be uptodate, valid, and lead to a usable path. I think the lack of specification for the final tie-breaker in the RFC was intentional :-) The specification has to address this, and until the situation is more clear cut than it is now I don't see any benefit for changing Linux's behavior. Especially since there is a configuration based workaround which works for people in the short-term. But I'm willing to be convinced, and those wanting to convince me can post a patch for review to netdev@vger.kernel.org :-)