Re: [DNSOP] DNSOP Call for Adoption - draft-west-let-localhost-be-localhost

Tony Finch <dot@dotat.at> Tue, 12 September 2017 10:41 UTC

Return-Path: <dot@dotat.at>
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 5C10E1333A8 for <dnsop@ietfa.amsl.com>; Tue, 12 Sep 2017 03:41:37 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.2
X-Spam-Level:
X-Spam-Status: No, score=-4.2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3] 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 djpjz6ABe_XW for <dnsop@ietfa.amsl.com>; Tue, 12 Sep 2017 03:41:35 -0700 (PDT)
Received: from ppsw-32.csi.cam.ac.uk (ppsw-32.csi.cam.ac.uk [131.111.8.132]) (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 33E0313339D for <dnsop@ietf.org>; Tue, 12 Sep 2017 03:41:35 -0700 (PDT)
X-Cam-AntiVirus: no malware found
X-Cam-ScannerInfo: http://help.uis.cam.ac.uk/email-scanner-virus
Received: from grey.csi.cam.ac.uk ([131.111.57.57]:59020) by ppsw-32.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.136]:25) with esmtps (TLSv1:ECDHE-RSA-AES256-SHA:256) id 1dridE-0000gI-3A (Exim 4.89) (return-path <dot@dotat.at>); Tue, 12 Sep 2017 11:41:29 +0100
Date: Tue, 12 Sep 2017 11:41:28 +0100
From: Tony Finch <dot@dotat.at>
To: Wes Hardaker <wjhns1@hardakers.net>
cc: John Levine <johnl@taugh.com>, dnsop@ietf.org
In-Reply-To: <yblr2vcxzjn.fsf@w7.hardakers.net>
Message-ID: <alpine.DEB.2.11.1709121124250.2628@grey.csi.cam.ac.uk>
References: <20170911013510.17202.qmail@ary.lan> <yblr2vcxzjn.fsf@w7.hardakers.net>
User-Agent: Alpine 2.11 (DEB 23 2013-08-11)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/sK_ni1gEZ6CXQ7pVNjpZFfysBP4>
Subject: Re: [DNSOP] DNSOP Call for Adoption - draft-west-let-localhost-be-localhost
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: Tue, 12 Sep 2017 10:41:37 -0000

Wes Hardaker <wjhns1@hardakers.net> wrote:
>
> Specifically, we have multiple naming systems already, and I'd argue
> that localhost actually isn't in the DNS naming system.  There is no
> authoritative source for it.  In fact, DNSSEC proves this.
>
> Instead, localhost is a operating system convention, a /etc/hosts name,
> an NIS name, or one of the other things that is able to resolve that
> name.  But the DNS is not where that resolution comes from.

I think this makes sense, but it isn't the whole story. From my brief look
at a small amount of traffic, localhost queries are basically all handled
inside the stub, so it is de facto as you describe. But it has long been
the case that DNS servers are also supposed to handle localhost, e.g.

RFC 1537 section 10
RFC 1912 section 4.1
RFC 2606 section 2
RFC 6761 section 6.3

However, implementations differ - BIND requires explicit configuration,
Unbound handles localhost by default.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/  -  I xn--zr8h punycode
South Utsire, Forties, Cromarty, Forth: Westerly 5 or 6, becoming variable 3
or 4, then northerly or northeasterly 5 or 6, occasionally 7 in Forties.
Moderate occasionally rough in Forties. Rain. Good occasionally poor.