From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: /128 link-local subnet on 6in4 (sit) tunnels? Date: Wed, 27 Mar 2013 19:35:58 +0100 Message-ID: <20130327183558.GC23223@order.stressinduktion.org> References: <1364335457.8215.21.camel@localhost> <20130327151210.GA23223@order.stressinduktion.org> <1364398673.21709.4.camel@localhost> <20130327181146.GB23223@order.stressinduktion.org> <1364408454.15362.1.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: netdev@vger.kernel.org, YOSHIFUJI Hideaki To: Wilco Baan Hofman Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:34577 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753554Ab3C0Sf7 (ORCPT ); Wed, 27 Mar 2013 14:35:59 -0400 Content-Disposition: inline In-Reply-To: <1364408454.15362.1.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Mar 27, 2013 at 07:20:54PM +0100, Wilco Baan Hofman wrote: > > > On Wed, 2013-03-27 at 19:11 +0100, Hannes Frederic Sowa wrote: > > On Wed, Mar 27, 2013 at 04:37:53PM +0100, Wilco Baan Hofman wrote: > > > > > > Weird, but sure, here goes: > > > > > > ip tunnel add tunv6-uplink1 mode sit remote 192.168.1.1 local > > > 192.168.1.21 > > > ip link set tunv6-uplink1 up mtu 1472 > > > > In my test I didn't specify the local address so addr.s6_addr32[3] > > seems to be zero. I'll have to search the RFCs why this is the case. > > See section 3.7, rfc4213: > > The interface identifier [RFC3513] for such an interface may be based > on the 32-bit IPv4 address of an underlying interface, or formed > using some other means, as long as it is unique from the other tunnel > endpoint with a reasonably high probability. > > http://tools.ietf.org/html/rfc4213 Thanks, I have seen that already. The sit driver is used for more than 6in4 (6to4, isatap, 6rd). So such a change has to be ok with all the other protocols implemented by sit. I also looked in the historic git archive for a rationale of this but couldn't find one. Commit messages 2002 where not as descriptive as today("Import changeset"). :) I also added YOSHIFUJI Hideaki as Cc, perhaps he knows the reason.