Re: [DNSOP] Comment on section 2 of draft-ietf-dnsop-nxdomain-cut-05.txt

Stephane Bortzmeyer <bortzmeyer@nic.fr> Thu, 29 September 2016 11:54 UTC

Return-Path: <bortzmeyer@nic.fr>
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 E000E12B017 for <dnsop@ietfa.amsl.com>; Thu, 29 Sep 2016 04:54:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9] 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 HFHN9XuSS3iV for <dnsop@ietfa.amsl.com>; Thu, 29 Sep 2016 04:54:13 -0700 (PDT)
Received: from mail.bortzmeyer.org (aetius.bortzmeyer.org [217.70.190.232]) (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 7381C12B0FD for <dnsop@ietf.org>; Thu, 29 Sep 2016 04:54:12 -0700 (PDT)
Received: by mail.bortzmeyer.org (Postfix, from userid 10) id F03CD31D88; Thu, 29 Sep 2016 13:54:10 +0200 (CEST)
Received: by godin (Postfix, from userid 1000) id 16806EC0B75; Thu, 29 Sep 2016 13:46:18 +0200 (CEST)
Date: Thu, 29 Sep 2016 13:46:18 +0200
From: Stephane Bortzmeyer <bortzmeyer@nic.fr>
To: "White, Andrew" <Andrew.White2@charter.com>
Message-ID: <20160929114618.GA21340@laperouse.bortzmeyer.org>
References: <29B4A430-80C7-44C8-A6FA-54A1560D3FD7@icann.org> <20160927004928.22EAE5515C31@rock.dv.isc.org> <89B42AE2-0377-42A4-B943-E65C52B7CB55@icann.org> <CAHPuVdVneekn9NL_u72KFk7aFQ8uWLkUDqAaW9c46SG-KDVuMg@mail.gmail.com> <d1da7014063b4525a25502408d9fbdc1@SC58MEXGP032.CORP.CHARTERCOM.com> <CAHPuVdVV_fqaiMuLuFKudFaT=FXTKE57+aYuf_HS+x-0OkOk0g@mail.gmail.com> <59500ec16f1041558d0b9f6646094ebf@SC58MEXGP032.CORP.CHARTERCOM.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <59500ec16f1041558d0b9f6646094ebf@SC58MEXGP032.CORP.CHARTERCOM.com>
X-Transport: UUCP rules
X-Operating-System: Ubuntu 16.04 (xenial)
X-Charlie: Je suis Charlie
User-Agent: Mutt/1.5.24 (2015-08-30)
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/BcAuUZfvcSXjBo9f847MaQJ3tFs>
Cc: Edward Lewis <edward.lewis@icann.org>, "dnsop@ietf.org" <dnsop@ietf.org>
Subject: Re: [DNSOP] Comment on section 2 of draft-ietf-dnsop-nxdomain-cut-05.txt
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.17
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: Thu, 29 Sep 2016 11:54:15 -0000

On Tue, Sep 27, 2016 at 07:28:57PM +0000,
 White, Andrew <Andrew.White2@charter.com> wrote 
 a message of 284 lines which said:

> True. When a resolver gets an NXDOMAIN for, say x.example.com, would
> it better to say the resolver SHOULD drop from cache all descendents
> of x.example.com, or MAY?

The current state of the draft is "approved by IESG". Which means
that, unless a serious bug is discovered, it will be published as a
RFC with only editorial changes (by the RFC editor). I don't think it
is a good idea to reopen a discussion which triggered aleady many
emails.

> It may be computationally expensive to search cache to remove cached
> NXDOMAIN responses below x.example.com, and I see no harm in letting
> those cached entries expire as their TTL runs out.

Which is exactly what the draft is saying:

   But if a resolver has cached data under the NXDOMAIN cut, it MAY
   continue to send it as a reply (until the TTL of this cached data
   expires), since this may avoid additional processing when a query is
   received.  Section 6 provides more information about this.