RE: [Int-area] Re: I-D ACTION:draft-fenner-iana-exp-2780-01.txt

"Dave Thaler" <dthaler@windows.microsoft.com> Fri, 13 January 2006 00:45 UTC

Received: from localhost.cnri.reston.va.us ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1ExD4f-0007ax-GG; Thu, 12 Jan 2006 19:45:49 -0500
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1ExD4a-0007aO-Nb for int-area@megatron.ietf.org; Thu, 12 Jan 2006 19:45:47 -0500
Received: from ietf-mx.ietf.org (ietf-mx [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id TAA13827 for <int-area@ietf.org>; Thu, 12 Jan 2006 19:44:23 -0500 (EST)
Received: from mail2.microsoft.com ([131.107.3.124]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1ExDBm-0003aq-Vc for int-area@ietf.org; Thu, 12 Jan 2006 19:53:12 -0500
Received: from mailout1.microsoft.com ([157.54.1.117]) by mail2.microsoft.com with Microsoft SMTPSVC(6.0.3790.2499); Thu, 12 Jan 2006 16:45:33 -0800
Received: from red-hub-04.redmond.corp.microsoft.com ([157.54.3.6]) by mailout1.microsoft.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 12 Jan 2006 16:45:33 -0800
Received: from win-imc-02.wingroup.windeploy.ntdev.microsoft.com ([157.54.69.169]) by red-hub-04.redmond.corp.microsoft.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 12 Jan 2006 16:45:33 -0800
Received: from win-msg-01.wingroup.windeploy.ntdev.microsoft.com ([157.54.5.41]) by win-imc-02.wingroup.windeploy.ntdev.microsoft.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 12 Jan 2006 16:45:32 -0800
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Subject: RE: [Int-area] Re: I-D ACTION:draft-fenner-iana-exp-2780-01.txt
Date: Thu, 12 Jan 2006 16:45:32 -0800
Message-ID: <2E33960095B58E40A4D3345AB9F65EC1152DB007@win-msg-01.wingroup.windeploy.ntdev.microsoft.com>
Thread-Topic: [Int-area] Re: I-D ACTION:draft-fenner-iana-exp-2780-01.txt
Thread-Index: AcYXd8c937TK+fqbQ4uLQC1CtXU6qQAXvgeA
From: Dave Thaler <dthaler@windows.microsoft.com>
To: Brian E Carpenter <brc@zurich.ibm.com>, Bill Fenner <fenner@research.att.com>
X-OriginalArrivalTime: 13 Jan 2006 00:45:32.0984 (UTC) FILETIME=[A8DA8380:01C617DA]
X-Spam-Score: 0.0 (/)
X-Scan-Signature: 7baded97d9887f7a0c7e8a33c2e3ea1b
Content-Transfer-Encoding: quoted-printable
Cc: int-area@ietf.org
X-BeenThere: int-area@lists.ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: IETF Internet Area Mailing List <int-area.lists.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/int-area>, <mailto:int-area-request@lists.ietf.org?subject=unsubscribe>
List-Archive: <http://www1.ietf.org/pipermail/int-area>
List-Post: <mailto:int-area@lists.ietf.org>
List-Help: <mailto:int-area-request@lists.ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/int-area>, <mailto:int-area-request@lists.ietf.org?subject=subscribe>
Sender: int-area-bounces@lists.ietf.org
Errors-To: int-area-bounces@lists.ietf.org

I believe this draft is useful.

Three issues:

1)
Brian Carpenter writes:
> > 2.4.2.  IPv4 Multicast
> >
> >    The globally routable group 224.0.1.20 is set aside for
> >    experimentation.  For certain experiments, the administratively
> >    scoped multicast groups defined in [RFC2365] may be
> >    useful.[[anchor10: Should there be a 'link-local' 224.0.0.x
> >    experiment group? --wcf]]
> 
> To me it doesn't really seem necessary. Any link-local resource is
> safe to use experimentally, subject to local administration.

Unfortunately, that's not really true.  Unlike in IPv6, there are no
link-local IPv4 multicast addresses which aren't in the range IANA uses
to assign to protocols to be hard-coded.  Per RFC 2365, IANA reserves 
a /24 in _every_ scope for it to use for this purpose.

http://www.iana.org/assignments/multicast-addresses
contains the list of the link-local assignments in the top section.

So I think there should indeed be a link-local 224.0.0.x experiment
group.  I think there is also justification for a scope-relative
experiment value.

2) Section 3.4.2 mentions an experimental IPv6 group address, but it 
would be good to add a statement (consistent with the 2nd sentence 
in 2.4.2) about the use of arbitrary scoped groups with the T=1 bit 
set.  In other words, whatever is said for IPv4 should be said for IPv6.

3) In the interest of saying what should not be done (like the statement
in section 1 about hard coding values), I believe section 3.4.1 (IPv6
Unicast Addresses) should contain a statement that it is inappropriate
to use RFC 3849 addresses in experiments.

-Dave

_______________________________________________
Int-area mailing list
Int-area@lists.ietf.org
https://www1.ietf.org/mailman/listinfo/int-area