IETF Logo Mail Archive

Re: [IPsec] draft-smyslov-ipsecme-ikev2-fragmentation-00 fragmentation size question

Paul Wouters <paul@cypherpunks.ca> Mon, 11 March 2013 15:12 UTC

Return-Path: <paul@cypherpunks.ca>
X-Original-To: ipsec@ietfa.amsl.com
Delivered-To: ipsec@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C91AE11E8104 for <ipsec@ietfa.amsl.com>; Mon, 11 Mar 2013 08:12:45 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.179
X-Spam-Level:
X-Spam-Status: No, score=-2.179 tagged_above=-999 required=5 tests=[AWL=0.420, BAYES_00=-2.599]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BgdSTZLy+AAQ for <ipsec@ietfa.amsl.com>; Mon, 11 Mar 2013 08:12:45 -0700 (PDT)
Received: from mx.nohats.ca (mx.nohats.ca [193.110.157.68]) by ietfa.amsl.com (Postfix) with ESMTP id 3524D11E8117 for <ipsec@ietf.org>; Mon, 11 Mar 2013 08:12:45 -0700 (PDT)
Received: from localhost (localhost [IPv6:::1]) by mx.nohats.ca (Postfix) with ESMTP id 3ZPjVL75NQz9cg; Mon, 11 Mar 2013 11:12:42 -0400 (EDT)
X-Virus-Scanned: amavisd-new at mx.nohats.ca
Received: from mx.nohats.ca ([IPv6:::1]) by localhost (mx.nohats.ca [IPv6:::1]) (amavisd-new, port 10024) with ESMTP id GsKBfhkgLGQE; Mon, 11 Mar 2013 11:12:40 -0400 (EDT)
Received: from bofh.nohats.ca (206-248-139-105.dsl.teksavvy.com [206.248.139.105]) by mx.nohats.ca (Postfix) with ESMTP; Mon, 11 Mar 2013 11:12:40 -0400 (EDT)
Received: by bofh.nohats.ca (Postfix, from userid 500) id A585F80D39; Mon, 11 Mar 2013 11:12:40 -0400 (EDT)
Received: from localhost (localhost [127.0.0.1]) by bofh.nohats.ca (Postfix) with ESMTP id 9A78580D38; Mon, 11 Mar 2013 11:12:40 -0400 (EDT)
Date: Mon, 11 Mar 2013 11:12:40 -0400
From: Paul Wouters <paul@cypherpunks.ca>
X-X-Sender: paul@bofh.nohats.ca
To: Valery Smyslov <svan@elvis.ru>
In-Reply-To: <62ABEDA45A2B4E2CBA7425644643F960@buildpc>
Message-ID: <alpine.LFD.2.03.1303111109550.17649@nohats.ca>
References: <alpine.LFD.2.03.1303081804390.15135@nohats.ca> <62ABEDA45A2B4E2CBA7425644643F960@buildpc>
User-Agent: Alpine 2.03 (LFD 1266 2009-07-14)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"; format="flowed"
Cc: "ipsec@ietf.org WG" <ipsec@ietf.org>
Subject: Re: [IPsec] draft-smyslov-ipsecme-ikev2-fragmentation-00 fragmentation size question
X-BeenThere: ipsec@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Discussion of IPsec protocols <ipsec.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipsec>, <mailto:ipsec-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ipsec>
List-Post: <mailto:ipsec@ietf.org>
List-Help: <mailto:ipsec-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipsec>, <mailto:ipsec-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 11 Mar 2013 15:12:45 -0000

On Mon, 11 Mar 2013, Valery Smyslov wrote:

>> I have a question about
>> 
>> http://tools.ietf.org/html/draft-smyslov-ipsecme-ikev2-fragmentation-00#section-2.5.1
>> 
>> It states:
>> 
>> 2.5.1. Fragment size

>> What is "message size" here referring to? The fragmentation payload, or
>> the total packet length?
>> 
>> That is, is it recommended that the packet size is 576/1280 including
>> the full IP header and ISAKMP header, or that the packet size is
>> 576/1280 plus the IP header and ISAKMP header?
>
> The total IP packet length (including IP header, UDP header, IKE header).
>
>> (and can the text in the next draft be clarified to indicate this
>> better?)
>
> Sorry for being not very precise. I'll try to clarify it in the next version.

It might be more useful to implementors to know the IKE message size
upon which they should fragment, as opopsed to having to calculate the
values of IP headers, UDP headers and IKE header with fragmentation
payload themselves? So can the draft specify those (and or both) ?

Paul

v2.23.0 | Report a Bug | By Email