====== Bind9 ======
  - <code bash>aptitude install bind9</code>
  - /etc/bind/named.conf.local: <file> zone "sub.example.com" IN {
  type master;
  file "/etc/bind/db.sub.example.com";
};
</file>
  - /etc/bind/db.sub.example.com: <file>
$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
;
</file>

===== Ports =====
  * TCP: 53
  * UDP: 53