Re: Additional Documentation Prefixes (was Re: AD Evaluation : draft-ietf-6man-ra-pref64-06)

Brian E Carpenter <> Sun, 03 November 2019 19:32 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id E878712008C for <>; Sun, 3 Nov 2019 11:32:43 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id UfH-ljgsV6zM for <>; Sun, 3 Nov 2019 11:32:42 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:4864:20::634]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 60D7D120086 for <>; Sun, 3 Nov 2019 11:32:42 -0800 (PST)
Received: by with SMTP id q16so6655688pll.11 for <>; Sun, 03 Nov 2019 11:32:42 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=PywUUnraTx0IsNfo8K/KLx3eIYvNlQmV0DmrQ14AJ+o=; b=ZXAFRxSyEGeaXXl6B+W5urIDOioyxhX5lYYZ6c77hONaQSb6fUDJMNk/pkBGwR3jVm wiNtlrg3cLrk66GvhlyOHhbW9cQWwaW7PYLoedD3Pv7hnKvgFCuTie5DDYcienNTqdUc nZKJdXoGtvh/uDKQfYaAZKyoJi78w9TZz/ekT6RLB4ePDYeTY/qNgFsliafimN1qdqy1 /Fl557IEjJYVujcJ+3b2UsLxBQ64bMdktGTidJp3piwb0nmmVo73OsgaziKKrAr2xMes UCPpoyMjL+DbjpHx5N2hXcKEVK5WyjwVizmO8zBv1VWzBxBvAYSnmOsHsWZGx6QugSmZ eKUw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=PywUUnraTx0IsNfo8K/KLx3eIYvNlQmV0DmrQ14AJ+o=; b=Elv5GfIdukIVGiIExrl5a8yxN44L3ssCwsNhwg6yJGxvnQyUqwiqzvMiHNuKgecS6+ 7OYc/hVOO/dNDyQUaI4/ZTM1CrWOFWeL1dstxhonzAigWlRXj8xmvpBkBwrbDHoM04ad QJu9ribVRY7dk5Ey4vCXGJUIbIkMhlkaMOpUamLqPVylmwPS2Heu40xJA8xJI5y0zyxP /pPxYk5HVPhfw/ngtDXI1Nxg6zdpX81KYrODPSJ5iFHPAmoLBZlm01in9oB3ehyyVIVP 3s8w0T9U57odA4ksLuT0Up7lVu7ZqKApGHgRzDWFnqJRMXIiI172F1eirnWc/l1hnCqc wTGw==
X-Gm-Message-State: APjAAAWpDdeYkmTzzbMh6Dc7/x4bp3wqa/tIwKWjizDPfRL2pQ8fm4rA 8laYI3YuryqGa4zt1D/yf0rglrMN
X-Google-Smtp-Source: APXvYqzWRKBX7YiQeYiRRVgDjz9mG5OZWgrZQbb5dKGc8mUyvatwaAwd7f1TV9bP25lEJhgTJqWpyw==
X-Received: by 2002:a17:902:a58c:: with SMTP id az12mr23402210plb.140.1572809561515; Sun, 03 Nov 2019 11:32:41 -0800 (PST)
Received: from [] ( []) by with ESMTPSA id q20sm513897pff.134.2019. (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 03 Nov 2019 11:32:40 -0800 (PST)
Subject: Re: Additional Documentation Prefixes (was Re: AD Evaluation : draft-ietf-6man-ra-pref64-06)
To: Michael Richardson <>, Suresh Krishnan <>
Cc: IETF IPv6 Mailing List <>
References: <> <> <27802.1572732078@localhost> <> <24180.1572801507@localhost>
From: Brian E Carpenter <>
Message-ID: <>
Date: Mon, 4 Nov 2019 08:32:39 +1300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0
MIME-Version: 1.0
In-Reply-To: <24180.1572801507@localhost>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable
Archived-At: <>
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sun, 03 Nov 2019 19:32:44 -0000

On 04-Nov-19 06:18, Michael Richardson wrote:
> Suresh Krishnan <> wrote:
>     >> I'd also like to have three or four additional IPv6 documentation prefixes,
>     >> plus some documentation space from ULA-R and ULA-C.
>     > What is ULA-R? Did you mean ULA-L? If so, it would be a pain to reserve
>     > something now since we also need to update RFC4193 to make sure that
>     > the Random “Global ID”s will not collide with the reserved prefixes. If
>     > ULA-C does take off, this would be a good idea to do something like
>     > this.
> I guess L=1 is why you call it ULA-L. I have known it as ULA-Random.
> We are both talking about RFC4193 though.  So such a document would need to
> update RFC4193.

I think this is a bad and pointless idea. Pointless because it is 100% OK
to use any RFC4193 prefix as an example, since by definition it will never
be used on the Internet, and the chance of collision on a given ULA site
is 1 in 2**40 (and who cares anyway?). Bad because it means that millions
of existing boxes that can generate ULA prefixes would be non-conformant
and, seriously, is any vendor going to update date their firmware for this?