What is a PTR record?

A PTR record maps an IP address to a hostname in reverse DNS. It is used for operational naming and frequently for mail-server identity checks.

Reading the result

Enter the public IPv4 or IPv6 address in Reverse DNS, complete verification, and search. You do not need to construct the PTR query name yourself.

PTR may be absent, and more than one value can be returned. NetKarte displays all names in the response.

Limitations

A PTR string does not prove ownership or trustworthiness. Forward-confirmed reverse DNS is not performed.

Forward and reverse records are independent

Suppose, illustratively, an IP has PTR mail.example.com. This does not establish that the name's A/AAAA points back to that IP. NetKarte displays returned PTRs without automatically verifying forward agreement.

Multiple records are separate names for the IP, not a priority list. Read Hostname and TTL per record. Missing PTR does not automatically prevent web browsing, and mail receivers use more than PTR alone.

The address provider or administrator normally controls reverse settings. A domain registrar or website designer cannot necessarily change them.