On Jul 18, 2014, at 10:18 AM, Tony Finch <d...@dotat.at> wrote: > Paul Vixie <p...@redbarn.org> wrote: >> >> what's unstated here is that every SMTP sender who encounters such an MX >> without understanding its new meaning will do two or three lookups: ". >> MX", > > No, MTAs do not look up MX records for MX targets. > >> [". AAAA",] and ". A". > > But they might do these lookups, yes. > > If this is a worry for the root server operators (but I thought they had > said in the past that it doesn't pose a problem) then the draft could > specify a canonical address-less domain lower down the hierarchy, e.g. > empty.as112.arpa (making use of the AS112 DNAME proposal). > > Tony. > -
Many years ago Joe Abley and I suggested to create a special name for exactly this purpose a name that was guaranteed to never exist in the DNS thus the first lookup would always return NXDOMAIN thus the A+AAAA lookups would never take place. http://tools.ietf.org/html/draft-jabley-sink-arpa-03 Olafur _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
