Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)

Fernando Gont <fgont@si6networks.com> Sun, 14 February 2021 21:54 UTC

Return-Path: <fgont@si6networks.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1CD963A0C40; Sun, 14 Feb 2021 13:54:40 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.001
X-Spam-Level:
X-Spam-Status: No, score=0.001 tagged_above=-999 required=5 tests=[NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sx2tfken1Thk; Sun, 14 Feb 2021 13:54:38 -0800 (PST)
Received: from fgont.go6lab.si (fgont.go6lab.si [91.239.96.14]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A2FD23A0942; Sun, 14 Feb 2021 13:54:37 -0800 (PST)
Received: from [IPv6:2800:810:464:2b9:1c77:acfc:e6a8:1311] (unknown [IPv6:2800:810:464:2b9:1c77:acfc:e6a8:1311]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by fgont.go6lab.si (Postfix) with ESMTPSA id 5409728062A; Sun, 14 Feb 2021 21:54:33 +0000 (UTC)
To: Ted Lemon <mellon@fugue.com>, David Farmer <farmer@umn.edu>
Cc: Brian E Carpenter <brian.e.carpenter@gmail.com>, IPv6 Operations <v6ops@ietf.org>, "6man@ietf.org" <6man@ietf.org>
References: <160989494094.6024.7402128068704112703@ietfa.amsl.com> <6fe3a45e-de65-9f88-808d-ea7e2abdcd16@si6networks.com> <F4E00812-E366-4520-AE17-7BB46E28D575@gmail.com> <CAN-Dau3iOjjU+FLpdtA7nqfKRX+sjjSanAU8U-O3pH-k5nSoig@mail.gmail.com> <a3fbfb94-90ae-961c-a2ab-33ade27e074e@si6networks.com> <672bd5e6-bdce-5915-1082-1ed30d3c5980@gmail.com> <CAN-Dau1CvbwZccq2Zyr8xBkiW1z0nKX_YcGW-y3VL7=pm+wA+w@mail.gmail.com> <227CDF8C-E929-4AA5-9D24-733381EB5C69@fugue.com> <CAN-Dau0JsMJ6Ad1pqeEKSKpRiSXDibMG4yKdVOKL4uFoqi5sAQ@mail.gmail.com> <EED3FE0C-1CE6-4472-895A-7BA6C6A998F3@fugue.com>
From: Fernando Gont <fgont@si6networks.com>
Message-ID: <4cebe185-0b1b-04c1-4a89-b6c207bb82bb@si6networks.com>
Date: Sun, 14 Feb 2021 18:52:56 -0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1
MIME-Version: 1.0
In-Reply-To: <EED3FE0C-1CE6-4472-895A-7BA6C6A998F3@fugue.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/v6ops/IU2-xurSDyveh3E2mGrONJnswo4>
Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 14 Feb 2021 21:54:40 -0000

On 14/2/21 18:32, Ted Lemon wrote:
[...]
> 
> My question to you is this: how does your proposed update help anybody 
> to understand?
> 
> If we were to update the text, I would suggest something like this:
> 
> Global scope, for uniquely identifying interfaces anywhere on the 
> Internet. Note that when we say an address is “globally unique,” this is 
> a definitional assertion: such an address is to be treated as globally 
> unique by hosts and routers. Mechanisms for ensuring that this 
> definitional assertion is not violated exist for each type of globally 
> scoped address, and in some cases rather than ensuring that a globally 
> /scoped/ address is in fact unique, these mechanisms ensure that the use 
> of such addresses is constrained to contexts in which they are /known/ 
> to be unique.

If the definition of scope is that of RFC4007:

       "[the] topological span within which the address may be used as a
       unique identifier for an interface or set of interfaces

ULAs can't be global.

So, either ULAs (and others) are not global, or scope means something 
different than what's in RFC4007.

i.e. the key is in the definition of "scope".

Since I find the definition of scope in RFC4007 quite succint and clear, 
my take is/was that the easier and simpler fix is that ULAs are not global.

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: fgont@si6networks.com
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492