From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John W. Linville" Subject: Re: IPv6 nexthop for IPv4 Date: Thu, 26 Mar 2015 11:43:36 -0400 Message-ID: <20150326154336.GA2528@tuxdriver.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Sowmini Varadhan , netdev , Andy Gospodarek To: =?iso-8859-1?Q?Bj=F8rnar?= Ness Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:57710 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415AbbCZPpP (ORCPT ); Thu, 26 Mar 2015 11:45:15 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Mar 26, 2015 at 04:10:21PM +0100, Bj=F8rnar Ness wrote: > 2015-03-26 15:53 GMT+01:00 Sowmini Varadhan : > > On Thu, Mar 26, 2015 at 10:39 AM, Bj=F8rnar Ness wrote: > > > >>>> ip route add 10.0.0.0/16 via fe80::225:90ff:fed3:bfb4/64 dev sfp= 0 > >>> > >>> Trying to understand what the desired behavior is, for the route > >>> above: if I send a packet from 10.0.0.1 to 10.0.0.2, you want the= dst-mac > >>> to be the mac address of e80::225:90ff:fed3:bfb4??? > >> > >> Absolutely, correct. > > > > What if the current node does not want to support ipv6? This sounds > > pretty "creative", if this can work, you might as well make the nex= thop to > > be the L2 address of the gw. >=20 > If it does not support IPv6 I guess the route command will fail! This > is a bad argument > against this. Dont see the point of limiting nexthop to L2 This topic was discussed at the recent Netconf event in Ottawa. This is a viable means of interconnecting two IPv4 "island" subnets across an IPv6 "ocean" backplane. Andy Gospodarek gave a short discussion on the topic, and IIRC it was warmly received. I'll Cc him on this message -- I think he had a (fairly simple) patch more or less ready. Hth! John --=20 John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.