$TTL 604800 @ IN SOA localhost. root.localhost. ( 1 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; @ NS localhost. ; $GENERATE 1-9 pc00$ A 192.168.102.$ $GENERATE 10-99 pc0$ A 192.168.102.$ $GENERATE 100-254 pc$ A 192.168.102.$