Re: [v6ops] PMTUD issue discussion

Fernando Gont <fgont@si6networks.com> Fri, 05 September 2014 02:06 UTC

Return-Path: <fgont@si6networks.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 0DAD81A033C for <v6ops@ietfa.amsl.com>; Thu, 4 Sep 2014 19:06:23 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham
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 ziaZCuxHw4Sr for <v6ops@ietfa.amsl.com>; Thu, 4 Sep 2014 19:06:20 -0700 (PDT)
Received: from web01.jbserver.net (web01.jbserver.net [IPv6:2a00:8240:6:a::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B672F1A0334 for <v6ops@ietf.org>; Thu, 4 Sep 2014 19:06:20 -0700 (PDT)
Received: from [186.134.41.131] (helo=[192.168.123.128]) by web01.jbserver.net with esmtpsa (TLSv1.2:DHE-RSA-AES128-SHA:128) (Exim 4.84) (envelope-from <fgont@si6networks.com>) id 1XPiui-0006kL-Nw; Fri, 05 Sep 2014 04:06:13 +0200
Message-ID: <540916FC.6030507@si6networks.com>
Date: Thu, 04 Sep 2014 22:50:52 -0300
From: Fernando Gont <fgont@si6networks.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0
MIME-Version: 1.0
To: "Fred Baker (fred)" <fred@cisco.com>
References: <0D370E74-688B-4EB3-A691-309A03AF20BA@cisco.com> <53FBA174.2040302@isi.edu> <53FBA6E1.90905@bogus.com> <CAPi140PMeM9omtm11+NHa2ywUfof_tE7HknKExtoEb32mm7L_w@mail.gmail.com> <71D0D5E8-80E9-430B-8ED4-16C1F99082CC@cisco.com> <54020ECC.4000000@globis.net> <CAEmG1=redpYUnv9R-uf+cJ4e+iPCf6zMHzVxeKNMGjcC=BjR+Q@mail.gmail.com> <5402C26A.8060304@globis.net> <540626F6.1020103@scea.com> <60533790-9A16-44C8-8239-89AE2C6BD783@cisco.com> <5408F6C6.3030103@gont.com.ar> <080303C1-D09F-4987-B114-F0F5C8B44863@cisco.com> <5409080E.7000200@si6networks.com> <9F0F552B-B465-40C4-8206-82A289294787@cisco.com>
In-Reply-To: <9F0F552B-B465-40C4-8206-82A289294787@cisco.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 8bit
Archived-At: http://mailarchive.ietf.org/arch/msg/v6ops/bKIBs4j7Tr9N2fL2dFAyg1XkmBM
Cc: "v6ops@ietf.org" <v6ops@ietf.org>, Tom Perrine <tperrine@scea.com>, Fernando Gont <fernando@gont.com.ar>
Subject: Re: [v6ops] PMTUD issue discussion
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 05 Sep 2014 02:06:23 -0000

On 09/04/2014 09:58 PM, Fred Baker (fred) wrote:
>>> 802.15.4?
>> 
>> No. I seem to recall that it was more of a packet radio sort of
>> thing (something predating 802.15.4). I could ask some folks if
>> interested in more details…
> 
> I think you missed my point. We have a case in point today, which is
> IPv6 in an IPv6 tunnel encapsulation running on a packet network
> whose MTU is 127 bytes. We call it “6lowpan”, and it runs on IEEE
> 802.15.4.

I expected 6lowpan to offer a virtual MTU >= 1280 (don't they), but
older stuff to not take care of that -- hence my comment.

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