Re: [Doh] No truncation for DNS over HTTPS

Andrew Sullivan <ajs@anvilwalrusden.com> Thu, 22 March 2018 13:52 UTC

Return-Path: <ajs@anvilwalrusden.com>
X-Original-To: doh@ietfa.amsl.com
Delivered-To: doh@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id F3E87124234 for <doh@ietfa.amsl.com>; Thu, 22 Mar 2018 06:52:11 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=yitter.info header.b=N56lRGLK; dkim=pass (1024-bit key) header.d=yitter.info header.b=RkbmV+44
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 A9_ht_nBaNFm for <doh@ietfa.amsl.com>; Thu, 22 Mar 2018 06:52:10 -0700 (PDT)
Received: from mx4.yitter.info (mx4.yitter.info [159.203.56.111]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A68211200C5 for <doh@ietf.org>; Thu, 22 Mar 2018 06:52:10 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by mx4.yitter.info (Postfix) with ESMTP id 097F1BE780 for <doh@ietf.org>; Thu, 22 Mar 2018 13:52:10 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yitter.info; s=default; t=1521726730; bh=QRypZgdechLgydtB1iILsEz3RcZVZAIrjvkWmKi45xM=; h=Date:From:To:Subject:References:In-Reply-To:From; b=N56lRGLKrXxcKaWDBOXpzeLDwSLOHDCaFXSpROD5PB5bk2NrBldF8DUft2Pbo9T82 S4ANw/rLkl8cNtNXzWT70kbwaoBljmXu6bGL0OpQin9FS8ggvukPUKuDd2xHzRq/xL mjl2S1MKix3B3HK3whmhMaFxrF9iOYkgIAFaYAQw=
X-Virus-Scanned: Debian amavisd-new at crankycanuck.ca
Received: from mx4.yitter.info ([127.0.0.1]) by localhost (mx4.yitter.info [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tnS4J15yGH8L for <doh@ietf.org>; Thu, 22 Mar 2018 13:52:08 +0000 (UTC)
Date: Thu, 22 Mar 2018 09:52:03 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yitter.info; s=default; t=1521726728; bh=QRypZgdechLgydtB1iILsEz3RcZVZAIrjvkWmKi45xM=; h=Date:From:To:Subject:References:In-Reply-To:From; b=RkbmV+446gWC0YwB5mV1j74JI6dSwWm/35+mhI3O4yYbU62U29C1UJTrfH9Tzdw6a b4j4G4lZpR7b+oikNQSRLjKc/zl1DfgCS17/y5HqMUlvaxXhRrTAD7Xrzb2l9ctWjy g4WYn2GjEVKGMRCUtggvn/UqPOrLwBGcDutkSeIc=
From: Andrew Sullivan <ajs@anvilwalrusden.com>
To: doh@ietf.org
Message-ID: <20180322135203.khatsujt6lym3vcb@mx4.yitter.info>
References: <CAAObRXJDV5Oa_d_S12HT2jqBuO=-AHOuMH8eKrac3BZ2bDxixw@mail.gmail.com> <alpine.DEB.2.11.1803221302420.2781@grey.csi.cam.ac.uk> <20180322133717.hxsqb53brrivn75q@mx4.yitter.info> <alpine.DEB.2.11.1803221343270.4063@grey.csi.cam.ac.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <alpine.DEB.2.11.1803221343270.4063@grey.csi.cam.ac.uk>
Archived-At: <https://mailarchive.ietf.org/arch/msg/doh/XucyQjWrox8lGRLPs93MhTCEpJc>
Subject: Re: [Doh] No truncation for DNS over HTTPS
X-BeenThere: doh@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: DNS Over HTTPS <doh.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/doh>, <mailto:doh-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/doh/>
List-Post: <mailto:doh@ietf.org>
List-Help: <mailto:doh-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/doh>, <mailto:doh-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 22 Mar 2018 13:52:12 -0000

On Thu, Mar 22, 2018 at 01:48:32PM +0000, Tony Finch wrote:
> True :-) I think my point is that if you have persistent back-end TCP
> connections (which you want for performance), there's no advantage to
> doing UDP - the TC dance slows things down, and dual-protocol backends
> have a complexity cost.

No question that an implemntation that did _not_ do as you say would
be boneheaded.  I am totally prepared to support a paragraph with
advice to implementers with this observation, but it's not 2119
protocol words, I think.

A

-- 
Andrew Sullivan
ajs@anvilwalrusden.com