Re: [v4v6interim] "IPv4->IPv6 is hard"

Iljitsch van Beijnum <iljitsch@muada.com> Fri, 17 October 2008 10:40 UTC

Return-Path: <v4v6interim-bounces@ietf.org>
X-Original-To: v4v6interim-archive@ietf.org
Delivered-To: ietfarch-v4v6interim-archive@core3.amsl.com
Received: from [127.0.0.1] (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 81EB53A6827; Fri, 17 Oct 2008 03:40:07 -0700 (PDT)
X-Original-To: v4v6interim@core3.amsl.com
Delivered-To: v4v6interim@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 1920B3A6827 for <v4v6interim@core3.amsl.com>; Fri, 17 Oct 2008 03:40:06 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Level:
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id n0dTjs-LN0vz for <v4v6interim@core3.amsl.com>; Fri, 17 Oct 2008 03:40:05 -0700 (PDT)
Received: from sequoia.muada.com (unknown [IPv6:2001:1af8:2:5::2]) by core3.amsl.com (Postfix) with ESMTP id 1E8D93A63CB for <v4v6interim@ietf.org>; Fri, 17 Oct 2008 03:40:04 -0700 (PDT)
Received: from [IPv6:2002:a375:547a:9:21b:63ff:fe02:3c13] ([IPv6:2002:a375:547a:9:21b:63ff:fe02:3c13]) (authenticated bits=0) by sequoia.muada.com (8.13.3/8.13.3) with ESMTP id m9HAeb4G031577 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Fri, 17 Oct 2008 12:40:40 +0200 (CEST) (envelope-from iljitsch@muada.com)
Message-Id: <4391DDA1-6432-4DCD-8A38-F351C68058B5@muada.com>
From: Iljitsch van Beijnum <iljitsch@muada.com>
To: Fred Baker <fred@cisco.com>
In-Reply-To: <B4A9FAB9-F39D-42AA-BE3B-AF6A3C48CC93@cisco.com>
Mime-Version: 1.0 (Apple Message framework v929.2)
Date: Fri, 17 Oct 2008 12:40:55 +0200
References: <B4A9FAB9-F39D-42AA-BE3B-AF6A3C48CC93@cisco.com>
X-Mailer: Apple Mail (2.929.2)
Cc: v4v6interim@ietf.org
Subject: Re: [v4v6interim] "IPv4->IPv6 is hard"
X-BeenThere: v4v6interim@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Discussion of coexistence topics for the 01-Oct-2008 v4-v6 coexistence interim meeting <v4v6interim.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/v4v6interim>, <mailto:v4v6interim-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/pipermail/v4v6interim>
List-Post: <mailto:v4v6interim@ietf.org>
List-Help: <mailto:v4v6interim-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v4v6interim>, <mailto:v4v6interim-request@ietf.org?subject=subscribe>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"; DelSp="yes"
Sender: v4v6interim-bounces@ietf.org
Errors-To: v4v6interim-bounces@ietf.org

[catching up...]

On 1 okt 2008, at 18:13, Fred Baker wrote:

> An IPv4 client accessing an IPv6 server is equally simple given a  
> 1:1 mapping such as NAT64 or IVI describes. One maps the headers and  
> the addresses.

[...]

> So to my mind, the requirement is that the gateway provide three  
> services:
>  - a DNS algorithm that maps IPv4 addresses to a subset of IPv6
>    addresses.
>  - a 1:1 NAT algorithm that statelessly supports the common case of
>    IPv4 clients accessing IPv6 servers, which will be used by a
>    relatively small set of hosts in the IPv6-only domain.
>  - 1 1:n NAT algorithm that statefully maps general IPv6 to IPv4
>    address plus port, which might be used by an arbitrarily large
>    number of hosts in the IPv6-only domain, but unlikely to be all
>    at the same time and diminishing as IPv6 deployment grows.

So you _don't_ want to solve the situation where an IPv4-only host  
gets to talk to any given IPv6 host.

I think it would be fair to call _that_ scenario "hard".

However, I think there are others who are interested in solving this  
case.
_______________________________________________
v4v6interim mailing list
v4v6interim@ietf.org
https://www.ietf.org/mailman/listinfo/v4v6interim