What does reverse DNS lookup return?
Reverse DNS maps an IPv4 or IPv6 address to the hostname published in its PTR record. The result is useful when interpreting mail servers, logs, network ownership, and service configuration because it shows the name the address holder chose to associate with that endpoint.
The server validates the address and performs a live dns.reverse query, returning every PTR hostname it receives. Only the owner of the address range can publish the record, but the value is not identity proof. This tool does not enumerate all websites sharing an address; that is a different and inherently incomplete dataset.