$origin zona01.dnssec.pt.
$TTL 14400      ; 4 hours
@               IN      SOA     dnssec01.dns.pt. hostmaster.zona01.dnssec.pt. (
                        2010021101      ; serial
                        14400           ; refresh (6 hours)
                        7200            ; retry (2 hours)
                        604800          ; expire (30 days)
                        300             ; minimum (5 minutes)
                        )
                IN      NS      dnssec01.dns.pt.
                IN      NS      dnssec02.dns.pt.