Pointer records (PTR) are used for reverse lookups. For example, to make 192.168.0.1 resolve to www.yourdomain.com, the record would look like:
18.104.22.168.in-addr.arpa PTR www.yourdomain.com.
Note: The IP address is reversed in the first field. Please use a period after your hostname (second field).
The “in-addr-arpa” method is the most frequently used.
Important: PTR records are effective only if your site has its own IP address.
PTR records are only effective if named.conf is manually edited and the proper zone information is added. This can only be done by a root user (the server Admin).