Getting the name of responding server(s)

[Stephane Bortzmeyer]

On Thu, Sep 09, 2021 at 12:33:22PM +0200,
 Matus UHLAR - fantomas <uhlar at fantomas.sk> wrote 
 a message of 59 lines which said:

> Note that some domains can be horribly broken and different
> nameservers can send different NS, or no NS at all but SOA.

Doing this sort of survey on the wild (and wide) Internet leads
rapidly into a deep rabbit hole :-)

If you go that way, one may also add to the requirments: "test the
name servers returned, to see if they actually reply (and with bit
AA)".