Because without such a signal, humans using ANY for legitimate diagnostic purposes have no means of differentiating section 4.1/4.3 "subset" responses from conventional responses where there just happen to be only a small number of RRSets at the queried name, encouraging (or at least doing nothing to dissuade) a conclusion that the response is in fact conventional and complete.
On Fri, Feb 10, 2017 at 1:44 PM, Ólafur Guðmundsson <ola...@cloudflare.com> wrote: > Thank you for your comments > > Q: why do you think it is useful to complicate things with a EDNS0 flag ? > > Olafur > > > > On Thu, Feb 9, 2017 at 8:47 PM, Richard Gibson <rgib...@dyn.com> wrote: > >> With full realization that this is coming very late in the game, we had a >> great deal of internal conversation within Dyn about implementing >> refuse-any, and came away unsatisfied with both the "subset" and "HINFO" >> approaches—the latter because of reasons that have already been covered, >> and the former for lacking in-band signaling of non-"conventional" >> incompleteness to aid legitimate use. >> >> I believe there is sufficient cause to reserve a new OPT record EDNS >> header flag bit >> <http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-13> >> for indicating "partial response" (as distinct from "truncation"). It will >> be safely ignored by current clients, but convey the desired information to >> those in the know. >> >> P.S. Our discussion also raised some more minor points: >> >> - Insisting that the HINFO OS field SHOULD be empty ("set to the null >> string") seems a little too strong; there's room in it for (and value >> from) a short explanation (e.g., cloudflare.com. 3789 IN HINFO "Please >> stop asking for ANY" "See draft-ietf-dnsop-refuse-any"). I'd prefer >> text like "The OS field of the HINFO RDATA SHOULD be short to >> minimize the size of the response, and MAY be empty or MAY include a >> summarized description of local policy." >> - "Conventional [ANY] response" is used but not defined. >> - "ANY does not mean ALL" is misleading—RFC 1035 >> <https://tools.ietf.org/html/rfc1035#section-3.2.3> is clear about >> QTYPE=255 being "a request for *all* records" (emphasis mine). That >> said, the proposed *response* behavior is consistent with that RFC. >> >> >> On Thu, Feb 9, 2017 at 12:56 AM, <internet-dra...@ietf.org> wrote: >> >>> >>> A New Internet-Draft is available from the on-line Internet-Drafts >>> directories. >>> This draft is a work item of the Domain Name System Operations of the >>> IETF. >>> >>> Title : Providing Minimal-Sized Responses to DNS >>> Queries that have QTYPE=ANY >>> Authors : Joe Abley >>> Olafur Gudmundsson >>> Marek Majkowski >>> Filename : draft-ietf-dnsop-refuse-any-04.txt >>> Pages : 10 >>> Date : 2017-02-08 >>> >>> Abstract: >>> The Domain Name System (DNS) specifies a query type (QTYPE) "ANY". >>> The operator of an authoritative DNS server might choose not to >>> respond to such queries for reasons of local policy, motivated by >>> security, performance or other reasons. >>> >>> The DNS specification does not include specific guidance for the >>> behaviour of DNS servers or clients in this situation. This document >>> aims to provide such guidance. >>> >>> >>> The IETF datatracker status page for this draft is: >>> https://datatracker.ietf.org/doc/draft-ietf-dnsop-refuse-any/ >>> >>> There's also a htmlized version available at: >>> https://tools.ietf.org/html/draft-ietf-dnsop-refuse-any-04 >>> >>> A diff from the previous version is available at: >>> https://www.ietf.org/rfcdiff?url2=draft-ietf-dnsop-refuse-any-04 >>> >>> >>> Please note that it may take a couple of minutes from the time of >>> submission >>> until the htmlized version and diff are available at tools.ietf.org. >>> >>> Internet-Drafts are also available by anonymous FTP at: >>> ftp://ftp.ietf.org/internet-drafts/ >>> >>> _______________________________________________ >>> DNSOP mailing list >>> DNSOP@ietf.org >>> https://www.ietf.org/mailman/listinfo/dnsop >>> >> >> >> _______________________________________________ >> DNSOP mailing list >> DNSOP@ietf.org >> https://www.ietf.org/mailman/listinfo/dnsop >> >> >
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