Re: [DNSOP] I-D Action: draft-ietf-dnsop-avoid-fragmentation-00.txt

Mukund Sivaraman <muks@mukund.org> Wed, 08 July 2020 15:18 UTC

Return-Path: <muks@mukund.org>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3B8F33A0DCC for <dnsop@ietfa.amsl.com>; Wed, 8 Jul 2020 08:18:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.09
X-Spam-Level:
X-Spam-Status: No, score=-2.09 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, T_SPF_HELO_TEMPERROR=0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=mukund.org
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 AhlYcithT8ed for <dnsop@ietfa.amsl.com>; Wed, 8 Jul 2020 08:18:47 -0700 (PDT)
Received: from jupiter.mukund.org (jupiter.mukund.org [46.4.226.158]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 5136A3A0DB7 for <dnsop@ietf.org>; Wed, 8 Jul 2020 08:18:44 -0700 (PDT)
Date: Wed, 08 Jul 2020 20:48:30 +0530
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mukund.org; s=mail; t=1594221519; bh=zncdpgA/tqIKyYV/1FLprB/VzuVrl+aZOixrgtc06Cs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PBvy5n7GKTnwkfphCEoJQ+LkVaK+ENUpdHhQe5X6Wj4TkM6TwsJq+giH2P3pAVR6d 6n1tkteRo9uSwbIB5Rp4WI2t/rSWUb6+kQHKQZW6Jf8jZRp4RfliuVPO9WdwFt7RDV jXHDTWJouAh/ACg+H2KiLdllDvNXHl92dzD8qqNs=
From: Mukund Sivaraman <muks@mukund.org>
To: Marek Majkowski <majek04@gmail.com>
Cc: fujiwara@jprs.co.jp, paul@redbarn.org, dnsop@ietf.org
Message-ID: <20200708151830.GA317809@jurassic.vpn.mukund.org>
References: <159351340969.9763.13693079622434674195@ietfa.amsl.com> <20200708.170123.2054449579631699570.fujiwara@jprs.co.jp> <CABzX+qw11H1JSWT6_EcVirT1LNd9Sxqm4zEyjSrDEqc3j2Cgbg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="huq684BweRXVnRxX"
Content-Disposition: inline
In-Reply-To: <CABzX+qw11H1JSWT6_EcVirT1LNd9Sxqm4zEyjSrDEqc3j2Cgbg@mail.gmail.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/gZFjkWvgghBolelqd0vjjEy1KO0>
Subject: Re: [DNSOP] I-D Action: draft-ietf-dnsop-avoid-fragmentation-00.txt
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.29
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, 08 Jul 2020 15:18:57 -0000

On Wed, Jul 08, 2020 at 04:50:30PM +0200, Marek Majkowski wrote:
> > The maximum buffer size offered by an EDNS0 initiator SHOULD be
> > no larger than the estimated maximum DNS/UDP payload size...
> 
> This seems to indicate that EDNS0 over TCP should have a small buffer
> size as well. Consider wording like "...buffer size offered by an
> EDNS0 initator over UDP...".

The field has no effect in DNS over TCP. The EDNS "requestor's UDP
payload size" field that is encoded in the CLASS field of the OPT RR is
only used for DNS responses over UDP. It is ignored for DNS over TCP.

		Mukund