Re: [dhcwg] [v6ops] Stateful SLAAC (draft-ietf-v6ops-unique-ipv6-prefix-per-host)

Fernando Gont <> Mon, 13 November 2017 02:48 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 9BC47127077; Sun, 12 Nov 2017 18:48:29 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id zWo7OlW-t56j; Sun, 12 Nov 2017 18:48:28 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 4831F1241F5; Sun, 12 Nov 2017 18:48:28 -0800 (PST)
Received: from [IPv6:2001:67c:1232:144:8016:582c:2bf0:48c4] (unknown [IPv6:2001:67c:1232:144:8016:582c:2bf0:48c4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPSA id 8B95C80197; Mon, 13 Nov 2017 03:48:24 +0100 (CET)
To: Ted Lemon <>, Lorenzo Colitti <>
Cc: " WG" <>, "" <>, "" <>
References: <> <> <> <> <> <> <> <> <> <>
From: Fernando Gont <>
Message-ID: <>
Date: Mon, 13 Nov 2017 10:50:04 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=windows-1252
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Archived-At: <>
Subject: Re: [dhcwg] [v6ops] Stateful SLAAC (draft-ietf-v6ops-unique-ipv6-prefix-per-host)
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 13 Nov 2017 02:48:30 -0000

On 11/13/2017 10:17 AM, Ted Lemon wrote:
> On Nov 13, 2017, at 10:14 AM, Lorenzo Colitti <
> <>> wrote:
>> Excuse me, but I really cannot fathom why we are saying that this
>> draft defines a new protocol when it is an explicit goal for all
>> existing implementations to continue to work. How can this be a new
>> protocol when all implementations implement this already?
> All host implementations have to work.   In order for them to work, new
> router behavior has to be specified.   That sounds like a protocol spec
> to me.  My question would be, why is this a problem?   I think that the
> document could be clearer about required behavior, but it already
> basically says what needs to happen. 

If it's a BCP, then it should state what it wants to achieve, and note
that there is a standardized way to do it (DHCPv6-PD), and there are
products width non-standard mechanisms based SLAAC. And that's fair enough.

If somebody is willing to specify PD for SLAAC, then they should write
an I-D targeting 6man -- one might also wonder if also name it SSLAAC,
or just AAC (if there's a lack of a better name :-) )

Putting state into SLAAC will likely trigger "WTH!?" moments,
particulaly in folks that are already having a hard figuring out how all
the IPv6 automatic configuration pieces fit together.

I also wonder what's the logic with which we'd be specifying PD for
SLAAC... and also wondering if we're also going to specify a route
option for DHCPv6, and the like. And, if we're essentially going to
disregard anything and everything that can already be done in a standard
way with DHCPv6 and hack it into slaac instead, why we don't we just
close dhc wg.

Doing a half-baked sateful SLAAC for PD, and telling the community that
that's our best current practice seems to be like sending the wrong

Fernando Gont
SI6 Networks
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492