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> Wed, 06 January 2021 16:51 UTC

Return-Path: <fgont@si6networks.com>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 35C4F3A105E; Wed, 6 Jan 2021 08:51:57 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.16
X-Spam-Level:
X-Spam-Status: No, score=-2.16 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, NICE_REPLY_A=-0.262, 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 1iWwMfJTDdwR; Wed, 6 Jan 2021 08:51:54 -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 BB1893A0FE8; Wed, 6 Jan 2021 08:51:54 -0800 (PST)
Received: from [10.0.0.129] (unknown [186.19.8.47]) (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 2841E284F56; Wed, 6 Jan 2021 16:51:50 +0000 (UTC)
Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
To: Gert Doering <gert@space.net>
Cc: Philip Homburg <pch-ipv6-ietf-7@u-1.phicoh.com>, ipv6@ietf.org, IPv6 Operations <v6ops@ietf.org>
References: <160989494094.6024.7402128068704112703@ietfa.amsl.com> <6fe3a45e-de65-9f88-808d-ea7e2abdcd16@si6networks.com> <m1kx98E-0000EhC@stereo.hq.phicoh.net> <b53b5d62-0334-f791-f56a-f2122767ecdb@si6networks.com> <m1kxAVC-0000KhC@stereo.hq.phicoh.net> <c236e635-518b-fb51-5024-901ec4677c5d@si6networks.com> <20210106162652.GX13005@Space.Net>
From: Fernando Gont <fgont@si6networks.com>
Message-ID: <1ddf8850-a8cb-53a7-31bc-7433d5a984f2@si6networks.com>
Date: Wed, 6 Jan 2021 13:46:51 -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: <20210106162652.GX13005@Space.Net>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/OvpoXvRS4KdoM2iuwYbCkoc3Gww>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 06 Jan 2021 16:52:01 -0000

Hi, Gert,

On 6/1/21 13:26, Gert Doering wrote:
> HI,
> 
> On Wed, Jan 06, 2021 at 12:42:13PM -0300, Fernando Gont wrote:
>> And, as noted, there are concrete implications:
>> RFC4007 says ULAs are non-global, RFC4193 says that ULAs are global, and
>> a Python library says ULAs are non-global. I don't think we want that.
> 
> On a tangent, I wonder why this is relevant at all.
> 
> Why should applications, or anything that is not an admin, care if an
> address is a ULA or a GUA?

I can report on my own case:

I have Raspberry Pis that deploy here and there. In order to be able to 
access them, they use dynamic DNS to post their addresses on their DNS.
If I don't look at the properties of the addresses, then I end up puting 
crap on the DNS. One straightforward consequence is that many apps that 
don't do Happy Eyeballs end up having an insane connection-establishment 
period, if they happen to try the unusable addresses first.

So "find all your IPv6 addresses and post them to the DNS" doesn't work.




> (I can see the bit about "tools that enter GUAs in the global DNS",
> but this is very special anyway - because "DNS" might not be "global",
> so general "refuse to put ULA into DNS" is not correct behaviour either)

What I do is:
For each node, I have one domain name for global addresses, and another 
for non-globals.



> Consistent terminology is important, true, and if we just want to make
> sure that something can properly flag a ULA different than a GUA, we
> could just introduce
> 
>    "mid-range scoped"
> 
> or rename the scopes to be 0 (link-local), 5 (mid-range), 10 (global)...

Any of those options are totally fine. The point is that ULAs don't have 
the "global scope" properties described in RFC4007.

It is not acceptable to have folks that do their homework and read 
RFC4291/RFC4007, and then read other documents and are left scratching 
their heads.

If we can't fix specs when we have inconsistencies, I don't think we can 
expect people to make sense out of them.

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