IETF Logo Mail Archive

Re: [v4tov6transition] IPv6 VPNs configured over 1280 MTU tunnels

Rémi Després <remi.despres@free.fr> Mon, 11 October 2010 17:03 UTC

Return-Path: <remi.despres@free.fr>
X-Original-To: v4tov6transition@core3.amsl.com
Delivered-To: v4tov6transition@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 9EF783A6B4B; Mon, 11 Oct 2010 10:03:39 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.143
X-Spam-Level:
X-Spam-Status: No, score=-0.143 tagged_above=-999 required=5 tests=[AWL=-0.794, BAYES_50=0.001, HELO_EQ_FR=0.35, MIME_8BIT_HEADER=0.3]
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 G-2QYX1hUuk0; Mon, 11 Oct 2010 10:03:38 -0700 (PDT)
Received: from smtp23.services.sfr.fr (smtp23.services.sfr.fr [93.17.128.19]) by core3.amsl.com (Postfix) with ESMTP id A98BC3A6B48; Mon, 11 Oct 2010 10:03:38 -0700 (PDT)
Received: from filter.sfr.fr (localhost [127.0.0.1]) by msfrf2304.sfr.fr (SMTP Server) with ESMTP id A74CD7000098; Mon, 11 Oct 2010 19:04:50 +0200 (CEST)
Received: from [192.168.0.20] (per92-10-88-166-221-144.fbx.proxad.net [88.166.221.144]) by msfrf2304.sfr.fr (SMTP Server) with ESMTP id 31D467000095; Mon, 11 Oct 2010 19:04:50 +0200 (CEST)
X-SFR-UUID: 20101011170450204.31D467000095@msfrf2304.sfr.fr
Mime-Version: 1.0 (Apple Message framework v1081)
Content-Type: text/plain; charset="iso-8859-1"
From: Rémi Després <remi.despres@free.fr>
In-Reply-To: <E1829B60731D1740BB7A0626B4FAF0A65C59B797F3@XCH-NW-01V.nw.nos.boeing.com>
Date: Mon, 11 Oct 2010 19:04:49 +0200
Content-Transfer-Encoding: quoted-printable
Message-Id: <279A3292-A291-4BC0-8FCF-53120066931E@free.fr>
References: <C8D29306.3EDBD%yiu_lee@cable.comcast.com> <E1829B60731D1740BB7A0626B4FAF0A65C59B79387@XCH-NW-01V.nw.nos.boeing.com> <E1829B60731D1740BB7A0626B4FAF0A65C59B79491@XCH-NW-01V.nw.nos.boeing.com> <AANLkTik0_9CRSfi_O53MChgt5QH+-=aR8HO7v+fHiLwY@mail.gmail.com> <D8BB9123-C611-4476-AFA1-D0ADEEDB6270@free.fr> <E1829B60731D1740BB7A0626B4FAF0A65C59B797F3@XCH-NW-01V.nw.nos.boeing.com>
To: "Templin, Fred L" <Fred.L.Templin@boeing.com>
X-Mailer: Apple Mail (2.1081)
Cc: Softwires <softwires@ietf.org>, "v4tov6transition@ietf.org" <v4tov6transition@ietf.org>
Subject: Re: [v4tov6transition] IPv6 VPNs configured over 1280 MTU tunnels
X-BeenThere: v4tov6transition@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <v4tov6transition.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/v4tov6transition>, <mailto:v4tov6transition-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/v4tov6transition>
List-Post: <mailto:v4tov6transition@ietf.org>
List-Help: <mailto:v4tov6transition-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v4tov6transition>, <mailto:v4tov6transition-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 11 Oct 2010 17:03:39 -0000

Le 11 oct. 2010 à 18:42, Templin, Fred L a écrit :

>> ...
>> Actually, the 6a44 specification should, instead of 1280, 
>> require IPv4 MTU - 28 octets, both for hairpinning and 
>> traversal cases.
> 
> How can you be sure that IPv4 PMTUD will work in
> the traversal case?

In the to-host direction, because the ISP network is all what is left to traverse before reaching the CPE.

In the from host direction, one can't be sure, but doesnt' need to.
If a smaller PMTU is encountered further downstream, a PTB ICMPv6 error message will be returned from there.

RD

v2.23.0 | Report a Bug | By Email