WhoDNS

Network Tools

Ping, A Record lookup, HTTP test and Port status

Enter an IP address.

Frequently Asked Questions

What is a PTR lookup?
It is the opposite of an A record: from an IP address it finds the matching domain name. It is also called "reverse DNS".
Why is PTR important for a mail server?
Many receiving servers treat email from a server without a valid, matching PTR as suspicious or spam.