Re: [DNSOP] Perl related question on BULK RR
Tony Finch <dot@dotat.at> Tue, 28 March 2017 10:19 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 43D2C1293D9 for <dnsop@ietfa.amsl.com>; Tue, 28 Mar 2017 03:19:15 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.221
X-Spam-Level:
X-Spam-Status: No, score=-4.221 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_PASS=-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 T-50VwnonYbk for <dnsop@ietfa.amsl.com>; Tue, 28 Mar 2017 03:19:13 -0700 (PDT)
Received: from ppsw-33.csi.cam.ac.uk (ppsw-33.csi.cam.ac.uk [131.111.8.133]) (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 2BA91129353 for <dnsop@ietf.org>; Tue, 28 Mar 2017 03:19:13 -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]:43446) by ppsw-33.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.137]:25) with esmtps (TLSv1:ECDHE-RSA-AES256-SHA:256) id 1csoDW-0011Xp-iG (Exim 4.89) (return-path <dot@dotat.at>); Tue, 28 Mar 2017 11:19:10 +0100
Date: Tue, 28 Mar 2017 11:19:10 +0100
From: Tony Finch <dot@dotat.at>
To: "Woodworth, John R" <John.Woodworth@CenturyLink.com>
cc: "'dnsop@ietf.org'" <dnsop@ietf.org>, 'JW' <jw@pcthink.com>, "Ballew, Dean" <Dean.Ballew@CenturyLink.com>
In-Reply-To: <A05B583C828C614EBAD1DA920D92866BD0716932@PODCWMBXEX501.ctl.intranet>
Message-ID: <alpine.DEB.2.11.1703281107300.13590@grey.csi.cam.ac.uk>
References: <A05B583C828C614EBAD1DA920D92866BD0716932@PODCWMBXEX501.ctl.intranet>
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/TdaI3N4fqJc18s6_zuBJzSTMG8Q>
Subject: Re: [DNSOP] Perl related question on BULK RR
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, 28 Mar 2017 10:19:15 -0000
Woodworth, John R <John.Woodworth@CenturyLink.com> wrote: > Apologies but I did not hear the full question regarding BULK RR's and > the perl like back-references. If you could please repeat the question > we would be happy to comment. I didn't ask the question, but based on a quick look at the draft I think there might be a fun problem. Frequently, when you have string rewriting with substitution and iteration, you have a Turing-complete esoteric programming system. NAPTR very cunningly avoids this trap (IIRC) by constraining the rewrites to be on a strictly monotonically reducing suffix of the input. BULK does not itself have built-in iteration like NAPTR, but because it synthesizes records it interacts with the DNS's existing resolver loops: chasing delegations, and chasing CNAMEs and DNAMEs. Note that CNAMEs and DNAMEs are also chased within authoritative servers. So my question is, how does the BULK rewriting system interact with DNS loops? Is there a CPU-eating tarpit in there? Tony. -- f.anthony.n.finch <dot@dotat.at> http://dotat.at/ - I xn--zr8h punycode South Utsire: Northwesterly 4 or 5 backing southwesterly 3 or 4. Slight or moderate. Fog patches, drizzle. Moderate or good, occasionally very poor.
- [DNSOP] Perl related question on BULK RR Woodworth, John R
- Re: [DNSOP] Perl related question on BULK RR Tony Finch
- Re: [DNSOP] Perl related question on BULK RR John Levine
- Re: [DNSOP] Perl related question on BULK RR Stephane Bortzmeyer
- Re: [DNSOP] Perl related question on BULK RR Woodworth, John R
- Re: [DNSOP] Perl related question on BULK RR Woodworth, John R