Reverse DNS lookup (rDNS) translates an IP address back to a hostname. This is accomplished through PTR (pointer) records in the DNS system.

Reverse DNS is commonly used for:

• Email server verification and spam prevention
• Network troubleshooting and diagnostics
• Security analysis and threat identification
• Logging and audit trails

Not all IP addresses have reverse DNS records configured. The IP address owner is responsible for setting up PTR records with their internet service provider or hosting company.