IETF Logo Mail Archive

Re: [DNSOP] Working Group Last Call for draft-ietf-dnsop-edns-chain-query

Tony Finch <dot@dotat.at> Wed, 11 November 2015 11:35 UTC

Return-Path: <fanf2@hermes.cam.ac.uk>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A9AB41A9060 for <dnsop@ietfa.amsl.com>; Wed, 11 Nov 2015 03:35:28 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.211
X-Spam-Level:
X-Spam-Status: No, score=-4.211 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01] 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 gBGbajyLUm2x for <dnsop@ietfa.amsl.com>; Wed, 11 Nov 2015 03:35:24 -0800 (PST)
Received: from ppsw-40.csi.cam.ac.uk (ppsw-40.csi.cam.ac.uk [131.111.8.140]) (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 6BE601A9059 for <dnsop@ietf.org>; Wed, 11 Nov 2015 03:35:24 -0800 (PST)
X-Cam-AntiVirus: no malware found
X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/
Received: from hermes-2.csi.cam.ac.uk ([131.111.8.54]:60876) by ppsw-40.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.156]:25) with esmtpa (EXTERNAL:fanf2) id 1ZwTgQ-0006Py-ki (Exim 4.86_36-e07b163) for dnsop@ietf.org (return-path <fanf2@hermes.cam.ac.uk>); Wed, 11 Nov 2015 11:35:22 +0000
Received: from fanf2 by hermes-2.csi.cam.ac.uk (hermes.cam.ac.uk) with local id 1ZwTgQ-0003EM-E9 (Exim 4.72) for dnsop@ietf.org (return-path <fanf2@hermes.cam.ac.uk>); Wed, 11 Nov 2015 11:35:22 +0000
Date: Wed, 11 Nov 2015 11:35:22 +0000
From: Tony Finch <dot@dotat.at>
X-X-Sender: fanf2@hermes-2.csi.cam.ac.uk
To: dnsop <dnsop@ietf.org>
In-Reply-To: <20151111051856.GV18315@mournblade.imrryr.org>
Message-ID: <alpine.LSU.2.00.1511111130470.959@hermes-2.csi.cam.ac.uk>
References: <5635CF1A.4030803@gmail.com> <alpine.LSU.2.00.1511091301260.25050@hermes-2.csi.cam.ac.uk> <A8A3F4DA-EE53-4BA4-9EF7-6DCB6120350B@vpnc.org> <alpine.LSU.2.00.1511091651330.25050@hermes-2.csi.cam.ac.uk> <E78EC567-FE6A-41B5-92DF-084145171455@vpnc.org> <alpine.LSU.2.00.1511102129030.24500@hermes-2.csi.cam.ac.uk> <20151111051856.GV18315@mournblade.imrryr.org>
User-Agent: Alpine 2.00 (LSU 1167 2008-08-23)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"
Sender: Tony Finch <fanf2@hermes.cam.ac.uk>
Archived-At: <http://mailarchive.ietf.org/arch/msg/dnsop/7XBNRHYiRz2UuOpxOO5b8toD6zU>
Subject: Re: [DNSOP] Working Group Last Call for draft-ietf-dnsop-edns-chain-query
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 11 Nov 2015 11:35:28 -0000

Viktor Dukhovni <ietf-dane@dukhovni.org> wrote:
>
> Except in the presence of CNAME (possibly via DNAME) records, which
> might mean that the client needs more records to validate multiple
> nodes in the DNS tree.
>
> So without nameserver assistance 1RTT via parallelism is not always
> possible.

Yes, with aliases you sometimes need 2RTT.

However edns-chain-query also has a problem with aliases since the server
doesn't know what the client might already have cached regarding the CNAME
or DNAME target. The server has to either send too little information, in
which case the client needs a second round trip, or too much information,
in which case it negates the bandwidth saving.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
Irish Sea: Southwesterly 6 to gale 8, but 4 or 5 at first in north. Moderate
or rough. Rain or drizzle, squally showers later. Moderate or good,
occasionally poor.

v2.23.0 | Report a Bug | By Email