SOA MNAME field

[Nicolai Langfeldt]

Bill Moseley <moseley at hank.org> tastet:
> Is the SOA's MNAME field used for any normal processing these days?  I know
> from DNS & Bind that 8.1 didn't like it if there wasn't an associated NS
> RR, but is that field used for anything these days?  What if the field is
> invalid?

In dynamic DNS (rfc2136) MNAME is used to identify the "primary master"
server, i.e., the master server that DDNS updates should be sent to.
So if the MNAME field is invalid in a zone then DDNS will not work with
that zone.

Note that DDNS is not enabled by default anyway so this is not a way
to make your DNS server more secure.  But if you don't need DDNS and
want your true master to be very stealthy you could enter something
bogus here.  It would not do much for the data-quality in DNS though.

Nicolai