Re: [DNSOP] Terminology question: split DNS

Jim Reid <jim@rfc1035.com> Mon, 19 March 2018 17:58 UTC

Return-Path: <jim@rfc1035.com>
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 09156126C25 for <dnsop@ietfa.amsl.com>; Mon, 19 Mar 2018 10:58:59 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.909
X-Spam-Level:
X-Spam-Status: No, score=-1.909 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
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 xYoKQ3SugWU3 for <dnsop@ietfa.amsl.com>; Mon, 19 Mar 2018 10:58:56 -0700 (PDT)
Received: from shaun.rfc1035.com (smtp.v6.rfc1035.com [IPv6:2001:4b10:100:7::25]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id AAE2212D7FC for <dnsop@ietf.org>; Mon, 19 Mar 2018 10:58:52 -0700 (PDT)
Received: from dhcp-8ed0.meeting.ietf.org (dhcp-8ed0.meeting.ietf.org [31.133.142.208]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by shaun.rfc1035.com (Postfix) with ESMTPSA id D78192421534; Mon, 19 Mar 2018 17:58:50 +0000 (UTC)
Content-Type: text/plain; charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\))
From: Jim Reid <jim@rfc1035.com>
In-Reply-To: <3D490CA8-0733-47AD-A088-113B1116B207@vpnc.org>
Date: Mon, 19 Mar 2018 17:58:48 +0000
Cc: dnsop <dnsop@ietf.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <7CF49D14-BF1C-4928-9A34-98FC739EFD7C@rfc1035.com>
References: <3D490CA8-0733-47AD-A088-113B1116B207@vpnc.org>
To: Paul Hoffman <paul.hoffman@vpnc.org>
X-Mailer: Apple Mail (2.3445.5.20)
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/2d_KrYWdUReOjRB2Dli6fdLvyzs>
Subject: Re: [DNSOP] Terminology question: split DNS
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.22
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: Mon, 19 Mar 2018 17:58:59 -0000


> On 19 Mar 2018, at 17:47, Paul Hoffman <paul.hoffman@vpnc.org>; wrote:
> 
> Some folks had reservations about the current definition of "split DNS":
>   "Where a corporate network serves up partly or completely different DNS inside and outside
>   its firewall. There are many possible variants on this; the basic point is that the
>   correspondence between a given FQDN (fully qualified domain name) and a given IPv4 address
>   is no longer universal and stable over long periods."
>   (Quoted from <xref target="RFC2775"/>, Section 3.8)
> 
> What would the WG like for this definition?

The quoted definition seems wrong: the binding of a name to address isn't necessarily unstable in split DNS setups. And that's not the only game in town either: for instance MX and NS records.

How about the following:

Where a corporate network serves up partly or completely different DNS data inside and outside its network. There are many possible variants on this; the basic point is that the
correspondence between a given QNAME/QTYPE/CLASS tuple and the data for that tuple is no longer universal and can depend on where the query is made from or which DNS server(s) are queried.