In order for your slave server(s) to be able to answer queries
about your domain, they must be able to transfer the zone information
from your primary server. Very few others have a need to do so.
Therefore restrict zone transfers using the allow-transfer
option, assuming 192.168.1.4 is the IP address of ns.friend.bogus and
adding yourself for debugging purposes:
zone "freebsd.bogus" { allow-transfer { 192.168.1.4; localhost; }; };
By restricting zone transfers you ensure that the only information available to people is that which they ask for directly - no one can just ask for all the details about your set-up.