Greetings,
Need advise how to setup one DNS server for multiple domain

names, like:  abcd._com_.xy, abcd._net_.xy, abcd._org_.xy, and

abcd._biz_.xy
The name server FQDN is server1.abcd._com_.xy (first domain)

but, how to name the server in the SOA record for the rest

of the domains?
Regards,
Mufurcz