$TTL 604800 @ SOA localhost. root.localhost. ( 1 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; Public zone roots, mailhubs and non-CNAME services (use A) NS localhost. A 10.42.42.42 ; 80.163.221.238 * A 10.42.42.42 ; 80.163.221.238