Reverse DNS (rDNS) is the process of resolving an IP address back to a domain name — the opposite of standard DNS resolution. Reverse DNS uses PTR (pointer) records and is commonly used for email server verification, network troubleshooting, and security logging. Many email servers check reverse DNS records to verify that an email sender's IP address matches a legitimate domain, helping filter spam.
FAQ
What is reverse DNS?
Reverse DNS looks up which domain name is associated with a given IP address — the opposite of normal DNS, which resolves domain names to IP addresses.