Re: [v6ops] PMTUD issue discussion

Jared Mauch <jared@puck.nether.net> Fri, 05 September 2014 00:46 UTC

Return-Path: <jared@puck.nether.net>
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 C6B311A0328 for <v6ops@ietfa.amsl.com>; Thu, 4 Sep 2014 17:46:37 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.57
X-Spam-Level:
X-Spam-Status: No, score=-2.57 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.668, 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 2MJBpmXFlZsq for <v6ops@ietfa.amsl.com>; Thu, 4 Sep 2014 17:46:36 -0700 (PDT)
Received: from puck.nether.net (puck.nether.net [IPv6:2001:418:3f4::5]) (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 B45861A0302 for <v6ops@ietf.org>; Thu, 4 Sep 2014 17:46:36 -0700 (PDT)
Received: from [172.22.208.164] ([162.210.130.4]) (authenticated bits=0) by puck.nether.net (8.14.8/8.14.5) with ESMTP id s850ioqb013263 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 4 Sep 2014 20:44:51 -0400
Mime-Version: 1.0 (Mac OS X Mail 8.0 \(1974.6\))
Content-Type: text/plain; charset="windows-1252"
From: Jared Mauch <jared@puck.nether.net>
In-Reply-To: <080303C1-D09F-4987-B114-F0F5C8B44863@cisco.com>
Date: Thu, 04 Sep 2014 20:46:28 -0400
Content-Transfer-Encoding: quoted-printable
Message-Id: <6E0095E7-5384-4097-A66C-BB1FB3D6354C@puck.nether.net>
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>
To: Fred Baker <fred@cisco.com>
X-Mailer: Apple Mail (2.1974.6)
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (puck.nether.net [204.42.254.5]); Thu, 04 Sep 2014 20:44:51 -0400 (EDT)
Archived-At: http://mailarchive.ietf.org/arch/msg/v6ops/VLP9m4IeAYO8XLd4-ZvS698NSVk
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 00:46:37 -0000

> On Sep 4, 2014, at 8:24 PM, Fred Baker (fred) <fred@cisco.com> wrote:
> 
> 
> On Sep 5, 2014, at 9:33 AM, Fernando Gont <fernando@gont.com.ar> wrote:
> 
>> What happens when/if such lins employ v6 (whether they really offer a
>> "virtual" MTU >=1280).. I just don't know.
> 
> 802.15.4?

I really want to drag anyone who thinks breaking p-mtu by their improper understanding of standards to do tech support for grandmas impacted by their issues.

The big problems we have is IETF wrote down 1280 when most links were already 1500 to be ‘safe’ and allowed this broken behavior to drive average packet sizes down.  I have equipment from vendors that can’t do average packet sizes lower than 330 bytes, so I really need that higher end packet size to bring the average up as a result.

We need to make P-MTU mandatory and not enable those who build broken networks any more.

- Jared