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Free PTR lookup

Look up the hostname published for an IPv4 or IPv6 address. Paste a domain and we reverse each address it resolves to.

Lookups use Cloudflare 1.1.1.1 from your browser.

Results appear here.

Reverse DNS matters for mail serversIf you send mail, the PTR of the sending IP should match the HELO name. Tenium monitors the host and the SMTP port those addresses sit on.

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What a PTR record is

PTR is reverse DNS: an IP address points back at a hostname. Mail receivers often reject or spam-folder messages when the sending IP has no PTR, or when the PTR name does not match the forward lookup.

Who publishes it

You do not set PTR in your own zone. The owner of the IP block does, which is usually the hosting or cloud provider. A missing PTR here is fixed in their panel, not in your DNS host.

Related checks

A lookup · AAAA lookup · MX lookup · DNS monitoring

Command-line equivalent

dig -x 1.1.1.1

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