Reverse DNS – What is it?
Reverse DNS or, for short rDNS maps an IP address to its corresponding domain name. It acts in the opposite direction of Forward DNS, where the domain name points to the corresponding IP address. Typically rDNS is offered by DNS hosting providers as an additional service. However, when you decide to use it, you should also create a Master Reverse zone and PTR records. Thanks to them, you will be capable of providing proof that the exact IP address and your domain name actually match.