Re: 6MAN WG Last Call:draft-ietf-6man-ipv6-subnet-model-00.txt

JINMEI Tatuya / 神明達哉 <> Mon, 09 November 2009 05:39 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 205CD3A6820 for <>; Sun, 8 Nov 2009 21:39:51 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: 0.8
X-Spam-Status: No, score=0.8 tagged_above=-999 required=5 tests=[AWL=0.200, BAYES_00=-2.599, CHARSET_FARAWAY_HEADER=3.2, NO_RELAYS=-0.001]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 6Il79OLIXtaO for <>; Sun, 8 Nov 2009 21:39:50 -0800 (PST)
Received: from ( [IPv6:2001:4f8:3:36::162]) by (Postfix) with ESMTP id 2CE0D3A6AE0 for <>; Sun, 8 Nov 2009 21:39:50 -0800 (PST)
Received: from (unknown [IPv6:2001:dfb:0:16:21b:63ff:fe08:3e64]) by (Postfix) with ESMTPA id E3B7433C3B; Sun, 8 Nov 2009 21:40:14 -0800 (PST)
Date: Mon, 09 Nov 2009 14:40:13 +0900
Message-ID: <>
To: Brian Haberman <>
Subject: Re: 6MAN WG Last Call:draft-ietf-6man-ipv6-subnet-model-00.txt
From: JINMEI Tatuya / =?ISO-2022-JP?B?GyRCP0BMQEMjOkgbKEI=?= <>
User-Agent: Wanderlust/2.14.0 (Africa) Emacs/22.1 Mule/5.0 (SAKAKI)
MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka")
Content-Type: text/plain; charset=US-ASCII
Cc: Bob Hinden <>,
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 09 Nov 2009 05:39:51 -0000

(resending as I seem to have submitted the original one from the wrong

At Tue, 27 Oct 2009 06:24:47 -0400,
Brian Haberman <>; wrote:

>       Title     : IPv6 Subnet Model: the Relationship between
>                   Links and Subnet Prefixes
>       Author(s) : H. Singh, et al.
>       Filename  : draft-ietf-6man-ipv6-subnet-model-05.txt
>       Pages     : 11
>       Date      : 2009-05-15
> as a Proposed Standard.  Substantive comments and statements of support
> for advancing this document should be directed to the mailing list.
> Editorial suggestions can be sent to the document editor.  This last
> call will end on October 14, 2009.

I've read the latest version of the draft and support for advancing
it.  I'm glad this document now focuses on its original issue (and
sorry for the process delay if it was due to my objection to previous
versions and my slow responses).

I have one minor technical comment.  In Introduction the draft states:

   In addition to the Prefix List, individual addresses are on-link if
   they are the target of a Redirect Message indicating on-link, or the
   source of a valid Neighbor Solicitation or Neighbor Advertisement
   message.  Note that Redirect Messages can also indicate an address is
   off-link.  Individual address entries can be expired by the Neighbor
   Unreachability Detection mechanism.

Technically, (in my understanding) Redirect Messages do not directly
indicate an address is off-link.  What they can indicate are:
1. an address is on-link
2. an address is reachable via a different router than the redirect

normally #2 means the address is off-link, but, again, technically, my
understanding is that it doesn't have to be so.

Frankly, I don't understand the rationale of this note in this context
in the first place (I don't see any problem even if we remove this
sentence), but if the intent is to just note the role of redirect is
not limited to show an address being on-link, I'd suggest rephrase the
"Note that..." sentence as follows:

   Note that Redirect Messages can also designate an alternate better
   router to reach an address, in which case the address is normally

JINMEI, Tatuya
Internet Systems Consortium, Inc.