$TTL 86400 @ IN SOA localhost. hostmaster.localhost. ( 24041302 ; serial 21600 ; refresh after 6 hours 3600 ; retry after 1 hour 604800 ; expire after 1 week 86400 ) ; minimum TTL of 1 day ; @ IN NS ns1.in.thelinuxpro.net. @ IN NS ns2.in.thelinuxpro.net. ; 1.0.0 IN PTR localhost.