#
$TTL <ttl value>
<domain name>. IN SOA <nameserver name>. <user.email>. (
<serial>;  serial number
<refresh>; refresh value
<retry>;  retry value
<expire>;  expire value
#
<n-ttl>;  negative caching TTL of 1 day
<domain name>.  IN  NS  <authoritative NS name>.
<domain name>.  IN  NS  <authoritative NS name>.
#
#...
<hostname>.  IN  A  <IP address>
<hostname>.  IN  A  <IP address>
...