Bind9

aptitude install bind9

/etc/bind/named.conf.local:

 zone "sub.example.com" IN {
  type master;
  file "/etc/bind/db.sub.example.com";
};

/etc/bind/db.sub.example.com:

$TTL    604800
@       IN      SOA     localhost. root.localhost. (
                              2         ; Serial
                         604800         ; Refresh
                          86400         ; Retry
                        2419200         ; Expire
                         604800 )       ; Negative Cache TTL
;
@ IN NS sub.example.com
@ IN A 123.123.123.123
test IN A 123.123.123.124
;