[dns-operations] Authoritative name server replies NODATA for a non-existing domain

[Stephane Bortzmeyer]

On Thu, Apr 23, 2015 at 08:45:01AM +0200,
 Michał Kępień <michal.kepien at nask.pl> wrote 
 a message of 14 lines which said:

> This is fun - I never expected this bug to be publicly noticed for a
> TLD. It's only observable in the time span between wildcard record
> removal and the next run of "nsdc patch" on the slave

If you want to observe the bug, .NGO currently has it.

% for ns in $(dig +nodnssec +short NS ngo.); do
echo $ns
dig @$ns NS thisdomaincertainlydoesnotexist.ngo |& grep status:
done
a2.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31131
d0.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 53352
b2.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64718
b0.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 64539
c0.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 12983
a0.nic.ngo.
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 18142