A zone file is a computer file in ASCII text format that contains all resource records for a given domain.
Below is a copy of a standard zone file containing the information for the Internet domain InetDaemon.com:
inetdaemon.com. IN SOA ns1.hostsave.com. contact.hostsave.com. ( 2001121123 ; serial 102000 ; refres 108000 ; retry 102000 ; expiry 3600 ); minimum inetdaemon.com. IN NS 1.hostsave.com. inetdaemon.com. IN NS 2.hostsave.com. inetdaemon.com. IN NS 3.hostsave.com. inetdaemon.com. IN A 18.104.22.168 inetdaemon.com. IN MX 20 mail.hostsave.com. inetdaemon.com. IN MX 1 mail-incoming.hostsave.com. inetdaemon.com. IN MX 10 mail-incoming2.hostsave.com.
Let's walk through the zone file and I will explain the contents of the file, line by line.
inetdaemon.com. IN SOA ns1.hostsave.com. contact.hostsave.com. ( 2001121123 ; serial 102000 ; refres 108000 ; retry 102000 ; expiry 3600 ); minimum
This looks like six lines, but it's really just one line, a Start of Authority resource record.
The domain InetDaemon.Com, the Primary Authoritative Nameserver is named in the SOA resource record as ns1.hostsave.com. Then below are the settings for how often the secondary nameserver should pull the file and wait between checks, as well as how long information should be cached on any recursive nameservers that cached an answer they looked up on ns1.hostsave.com.
Note that the 'A' records that contain the IP Addresses for the mail exchanger (MX) and nameserver (NS) resource records in this domain are located in the 'hostsave.com' zone file, and should NOT be configured in the inetdaemon.com zone file.