Re: [v6ops] draft-moreiras-v6ops-rfc3849bis-00

"Antonio M. Moreiras" <> Sat, 17 August 2013 00:32 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 1146E11E8176 for <>; Fri, 16 Aug 2013 17:32:29 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, NO_RELAYS=-0.001]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id yBodghhpIAFr for <>; Fri, 16 Aug 2013 17:32:28 -0700 (PDT)
Received: from ( [IPv6:2001:12ff:0:4::5]) by (Postfix) with ESMTP id 240CE11E8158 for <>; Fri, 16 Aug 2013 17:32:28 -0700 (PDT)
Received: from (unknown [IPv6:2001:12ff:0:5::96]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPSA id 43A9020801B9; Fri, 16 Aug 2013 21:32:27 -0300 (BRT)
Message-ID: <>
Date: Fri, 16 Aug 2013 21:32:27 -0300
From: "Antonio M. Moreiras" <>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130801 Thunderbird/17.0.8
MIME-Version: 1.0
To: "Fred Baker (fred)" <>
References: <> <> <>
In-Reply-To: <>
X-Enigmail-Version: 1.5.2
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: Alejandro Acosta <>, " WG" <>
Subject: Re: [v6ops] draft-moreiras-v6ops-rfc3849bis-00
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: v6ops discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sat, 17 Aug 2013 00:32:29 -0000

On 16/08/13 18:12, Fred Baker (fred) wrote:
> Dumb question.
> I wonder if there is a less expensive way to go about this. By expensive, I mean "choke. you want a /20?". It has been argued that we need something that is shorter than a /32, and that we need something for ULAs. Whatever we do, it needs to be consistent with class examples that need to get typed into operational equipment. There's a lot more that has been said, but that's what I draw out of it.
> What if we shortened 2001:db8::/32 to 2001:db8::/29? I note that the prefix doesn't show up in, and the IANA counterpart mentions it only in a footnote.
> We could also delegate fc00:db8::/29, or something longer (/44 perhaps, allowing for the description of several ULA prefixes in documentation but not chewing up as much address space), by the same logic.
> I see the argument, but not for the size requested.

It's a very good question. For our BGP trainings at, as they are
today, we need at least a /27 (we have 23 simulated ASs in our lab, each
one using a /32).

Since APNIC could shorten the 2001:db8:: only to a /29, which is not
enough for our classes, we saw as a better alternative asking for a new
prefix. We thought that maybe we shouldn't be so conservative, asking
exactly for what we need at the moment. The /20 is the shortest prefix
allocated to an ISP in our region, and it seemed to be a good choice.