[dns-operations] NXDOMAIN vs NOERROR/no answers for non-existant records

[Stephane Bortzmeyer]

On Fri, Apr 03, 2020 at 12:31:38PM +0100,
 Matthew Richardson <matthew-l at itconsult.co.uk> wrote 
 a message of 75 lines which said:

> where mtgmon.itconsult.net & monitor.itconsult.net are delegated to
> different authoratitives.

IMHO, the authoritative name servers for monitor.itconsult.net are
correct and those for mtgmon.itconsult.net are wrong (sending NODATA
instead of NXDOMAIN, even for ANY queries.)