Reverse DNS and FCrDNS checker

Find PTR names for an IP address and verify whether they resolve back to the original address.

Queries are sent from NekoIP infrastructure. The target website is not contacted.

Enter an IP address to find its PTR name and verify the forward match.

Both IPv4 and IPv6 are supported.
Examples:

Result

Enter a value to see the result.

What this tool checks

The tool requests PTR for one IPv4 or IPv6 address and then resolves each returned hostname through A and AAAA for forward-confirmed reverse DNS.

How to read the result

A PTR name is selected by the address operator. FCrDNS passes only when the original address appears in the forward answer; this demonstrates consistency, not ownership or authentication.

Common problems

Missing reverse delegation, stale forward records and generic provider hostnames are common. PTR changes normally have to be requested from the IP provider, not the domain registrar.

Command-line example

dig -x 8.8.8.8

Related guides

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