Reverse DNS / PTR Record Check

Please enter IP to check
	Example: google.com or 74.125.226.82

What is Reverse DNS Lookup?

A reverse DNS lookup is exactly what it sounds like - rather than entering a domain name to determine the IP address it points to, you can enter an IP address and find out which domain name is the IP associated with. Also called PTR record lookup, reverse DNS is useful for preventing spam and validating relationships between IP assignees and domain registrants. Note: it is possible for multiple domain names to point to the same IP address or host. This is common for websites who buy up multiple top level domain names to avoid confusion (i.e. example.com, example.net, example.org). Shared web hosting services will also have numerous domains pointing to them.

A reverse DNS search can be helpful for a number of purposes. For web analytics and Internet traffic analysis, you can use a reverse DNS search to learn which Internet service provider (ISP) your visitors are using.

Reverse DNS is also helpful for network diagnostics. For example, when you run a traceroute, you’ll see each hop as an IP address, rather than a resolved domain name. Reverse DNS lookup lets you convert these IP addresses into meaningful host names.

Reverse DNS lookup may also be helpful for investigating or preventing spam. For example, a forward confirmed reverse DNS can help you when building a whitelist for email senders by ensuring that the registrar of a domain is the same as the IP assignee. This helps mitigate attacks or spam from hackers using zombie computers or forged domains.

For more information about an IP address assignee, you should also run a Whois IP search.