SOA MNAME usage and restrictions

[Paul Vixie]

> Does the MNAME field of the SOA record need to be the *canonical* name for
> the primary master for the zone, or can it be an alias?

if it matches the owner name of one of the NS RR's, then it has meaning.
if it doesn't, then it has no meaning and can be anything you want, like
a CNAME.

> What happens if the name of a slave is used in the MNAME field instead
> of the primary master (say, if there is a desire to keep the location
> the primary absolutely secret, in a stealth server setup)?  The notify
> feature uses the MNAME value in its determination of who to send NOTIFY
> messages to, but where else is it used?

NOTIFY is the only protocol-defined use for SOA MNAME.