Reverse DNS Lookup
Lookup PTR (pointer) records to find the hostname associated with an IP address. Useful for identifying mail servers, network infrastructure, and verifying server legitimacy.
About Reverse DNS (PTR Records)
What is Reverse DNS?
Reverse DNS (rDNS) lookup queries the DNS system to find the hostname associated with an IP address, using PTR (pointer) records. It's the opposite of a normal DNS lookup which resolves hostnames to IPs.
Reverse DNS (rDNS) lookup queries the DNS system to find the hostname associated with an IP address, using PTR (pointer) records. It's the opposite of a normal DNS lookup which resolves hostnames to IPs.
Common Use Cases:
- Email servers: Many mail servers require valid PTR records to prevent spam
- Network troubleshooting: Identify devices and services by hostname
- Security analysis: Verify the legitimacy of servers and infrastructure
- Logging: Human-readable names instead of IP addresses in logs
Forward Verification:
A properly configured PTR record should have matching forward DNS. This tool automatically checks if the returned hostname resolves back to the original IP address, which is a best practice for mail servers and critical infrastructure.
A properly configured PTR record should have matching forward DNS. This tool automatically checks if the returned hostname resolves back to the original IP address, which is a best practice for mail servers and critical infrastructure.
Why might an IP not have a PTR record?
- Residential or dynamic IP addresses typically don't have PTR records
- Private network IPs (RFC 1918 ranges)
- Cloud instances that haven't been configured with reverse DNS
- IP ranges not properly delegated in DNS