* o...@delong.com (Owen DeLong) [Wed 31 Aug 2016, 01:47 CEST]:
You don’t get NXDOMAIN when a nameserver gets a request for a zone it doesn’t serve.
Correct in most cases (there's an edge case where a server is [mis] configured as authoritative with its own empty . and its regular zones and allows global querying; it's similar to asking a root server for anything in a nonexistent TLD).
You either get SERVFAIL or you get NS records back as a referral.
Or REFUSED.
-- Niels.
