Getting the name of responding server(s)

[Stephane Bortzmeyer]

On Thu, Sep 09, 2021 at 03:20:14AM -0700,
 Ronald F. Guilmette <rfg at tristatelogic.com> wrote 
 a message of 48 lines which said:

> I don't want and don't need SOA records.  I want and need only the
> relevant NS records.

The algorithm proposed by Matt Pounsett uses the SOA but only to find
the NS (through the name of the closest enclosing ancestor domain).