$TTL 86400 ; 24 hours could have been written as 24h or 1D $ORIGIN localhost. ; line below expands to: localhost 1D IN SOA localhost root.localhost ; (SS,30/5/19) taken from http://www.zytrax.com/books/dns/ch6/localhost.html ; also https://wiki.samba.org/index.php/Setting_up_a_BIND_DNS_Server @ 1D IN SOA @ root ( 2019053001 ; serial 3h ; refresh 15 ; retry 1w ; expire 3h ; minimum ) @ 1D IN NS @ 1D IN A 127.0.0.1