Find Reverse-DNS/PTR using dig, nslookup, host

Reverse-DNS/PTR is used by mail servers. It is used to map an IP address to FQDN or hostname.

To find Reverse DNS record for an IP address, run

nslookup IP_ADDR_HERE

In this example IP 51.38.246.115 have a Reverse DNS record ok.serverok.in

Using dig

You can also use dig command to find PTR record for an IP address.

dig -x IP_ADDR_HERE
dig +short -x IP_ADDR_HERE

Using host

host IP_ADDR_HERE

See DNS