[dns-operations] I missed the announcement: .ARPA has beendeleted

[Florian Weimer]

* Crist Clark:

> Isn't the information there already, even if it isn't used? If you
> send a query for non-existent TLD, the you get the SOA record for
> . in the auth section of the NXDOMAIN response. If the TLD existed,
> but the next level didn't you get the SOA for the TLD, not the root.

The roots receive the full QNAME.  If the QNAME contains multiple
lables, a Name Error response could still happen if the TLD existed,
so TLD non-existence cannot be inferred in many cases.

Incrementally increasing the label count needs more queries and breaks
in some scenarios (involving misconfigurations, admittedly).