[Mobopts] Re: mmcastv6-ps Draft

Thomas C Schmidt <schmidt@informatik.haw-hamburg.de> Mon, 17 September 2007 12:21 UTC

Return-path: <mobopts-bounces@irtf.org>
Received: from [] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1IXFb5-0002hx-Gq; Mon, 17 Sep 2007 08:21:03 -0400
Received: from [] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1IXFb3-0002cC-ST for mobopts@irtf.org; Mon, 17 Sep 2007 08:21:01 -0400
Received: from mail2.is.haw-hamburg.de ([]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1IXFb2-0002Rn-8U for mobopts@irtf.org; Mon, 17 Sep 2007 08:21:01 -0400
Received: from mailgate.informatik.haw-hamburg.de (isis2.informatik.haw-hamburg.de []) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail2.is.haw-hamburg.de (Postfix) with ESMTP id 36EA1574D1; Mon, 17 Sep 2007 14:20:59 +0200 (CEST)
Received: from mailgate.informatik.haw-hamburg.de ([]) by localhost (mailgate.informatik.haw-hamburg.de []) (amavisd-new, port 10024) with LMTP id 25230-01-5; Mon, 17 Sep 2007 14:20:58 +0200 (CEST)
Received: from [] (e178184071.adsl.alicedsl.de []) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mailgate.informatik.haw-hamburg.de (Postfix) with ESMTP id 7E9FE3C00120; Mon, 17 Sep 2007 14:20:58 +0200 (CEST)
Message-ID: <46EE722D.7000409@informatik.haw-hamburg.de>
Date: Mon, 17 Sep 2007 14:25:17 +0200
From: Thomas C Schmidt <schmidt@informatik.haw-hamburg.de>
User-Agent: Thunderbird (Windows/20070728)
MIME-Version: 1.0
To: Stig Venaas <stig.venaas@uninett.no>
References: <46C738F7.8000008@informatik.haw-hamburg.de> <46D2A7D6.9080703@uninett.no> <46EE5F36.9010304@informatik.haw-hamburg.de> <46EE60F2.8060005@uninett.no>
In-Reply-To: <46EE60F2.8060005@uninett.no>
Content-Type: text/plain; charset="ISO-8859-15"; format="flowed"
X-Virus-Scanned: by amavisd-new at informatik.haw-hamburg.de
X-Virus-Scanned: ClamAV at mailgate.haw-hamburg.de
Content-Transfer-Encoding: quoted-printable
X-Spam-Score: 0.0 (/)
X-Scan-Signature: 9ed51c9d1356100bce94f1ae4ec616a9
Cc: mobopts <mobopts@irtf.org>
Subject: [Mobopts] Re: mmcastv6-ps Draft
X-BeenThere: mobopts@irtf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Mobility Optimizations <mobopts.irtf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/mobopts>, <mailto:mobopts-request@irtf.org?subject=unsubscribe>
List-Post: <mailto:mobopts@irtf.org>
List-Help: <mailto:mobopts-request@irtf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/mobopts>, <mailto:mobopts-request@irtf.org?subject=subscribe>
Errors-To: mobopts-bounces@irtf.org

Stig Venaas wrote:
> Thomas C Schmidt wrote:

>> [...]
>>> Worth mentioning scoped multicast? Using tunnel from HA you can when
>>> leaving your site continue receiving multicast from your site of
>>> site-local scope. If you join natively you will instead receive
>>> whatever that multicast group might be used for in the other site...
>> Yes, but there are issues to that: People tend to consider this a
>> security fraud, if you participate in link-local group while being away
>> (3775 says "should not be tunneled").
> Right, but how about site-local. Are you part of the site? I think in
> general when people today use VPNs from laptops to access things at
> home, they consider the laptop a part of the site. I would assume there
> would be some administrative setting whether the HA should tunnel site-
> scoped multicast.

Sorry, my mistake: The quote "should not ..." was about site-local mcast 
- for the link-local case RFC 3775 says "Multicast packets addressed to 
a multicast address with link-local scope [3], to which the mobile node 
is subscribed, MUST NOT be tunneled to the mobile node."

The picture of a VPN-scenario you are drawing appears natural to me, 
too. The difference of course is that today's VPN-configs express the 
explicit will of domain administrators, while 3775 describes a general 
mobility standard.

I guess it's reasonable to suggest that site-local mcast forwarding 
should be configurable at the HA. We can add that.



° Prof. Dr. Thomas C. Schmidt
° HAW Hamburg, Dept. Informatik
° University of Applied Sciences
° Berliner Tor 7, D 20099 Hamburg
° Germany, Fon: +49-40-42875-8157
° http://www.informatik.haw-hamburg.de/~schmidt

Mobopts mailing list