In message <4F564AC2.1040502@xxxxxxx>, Alessandro Vesely writes: > On 06/Mar/12 16:00, John R. Levine wrote: > > > >>> We seem to believe that the "D" part is deployed so that adding new > >>> "unknown" RRTypes is not an issue. > >> > >> I think this is correct, but OTOH someone recently asked about > >> possible issues in this area, and if I remember correctly, > >> received no response. > > > > Last month I ran into a guy on the dmarc list who complained that his > > server returns NOTIMP in response to queries for SPF records ("because > > it doesn't implement them") and clients were doing odd things. But > > it's been a long time since I've run into anyone else like that, so I > > agree, it's not an issue. > > Hm... I have no idea how such response gets cached. RFC 2136 says > that "an appropriate error will be returned to the requestor's caller" > when RCODE is SERVFAIL or NOTIMP. > > Is that the same case that Scott noticed when he wrote: > > Particularly when querying for SPF records of type SPF, persistent > 2 ServFail results are /not rare/. > > http://www.ietf.org/mail-archive/web/spfbis/current/msg00259.html > (emphasis added) > ? > > IIRC there was also a mirroring issue... > > At least, I think these issues will gradually vanish as the software > at the relevant servers gets upgraded. A RFC 1035 recursive server should be able to handle SPF. It's just a opaque data blob to it with a name, type, class and ttl attributes. To serve SPF a RFC 1035 needed to be upgraded as it had no way to store / load the record. DNS software developers should read Section 3.6. "Defining new types, classes, and special namespaces", especially the sentence: New definitions should be expected. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@xxxxxxx _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf