== How not to set up your DNS (part 9)

Presented in the now-traditional illustrated form:

 ; sdig ns gcluk.net
 ns1.gcluk.net.
 ns2.gcluk.net.
 ; dig mx web1.gcluk.net @ns1.gcluk.net
 [...]
 ;; ANSWER SECTION:
 web1.gcluk.net. IN A 65.98.36.90
 ;; AUTHORITY SECTION:
 web1.gcluk.net. IN NS .

(TTLs have been omitted for clarity.)

That's an interesting authority record they're returning; somewhat more
like a disclaimer of authority record, in fact.

The effects are closely related to what I saw in HowNotToDoDNSVII. In
this case, we first looked up the _A_ record and found one, but when
we tried to look for an _MX_ record the completely bogus _NS_ record
stymied our attempts. (Among other problems, there is no _A_ record
for the '_._', the DNS root.)