Reverse DNS Lookup
Find the hostname connected to any IP address.
Reverse DNS Lookup
Query the Pointer (PTR) records for an IP address to discover the hostname associated with it. Supports both IPv4 and IPv6.
Enter an IP address above to trace it back to its host domain.
What is Reverse DNS?
Normal DNS (Forward DNS) maps a domain name like example.com to an IP address like 1.2.3.4. Reverse DNS does exactly the opposite: it maps an IP address back to a domain name using a Pointer (PTR) record.
Why is Reverse DNS Important?
- Email Deliverability: Many email servers check the reverse DNS of an incoming connection. If the IP address does not resolve to the expected hostname, or doesn't have a PTR record at all, the email is likely to be marked as spam or rejected entirely.
- Network Troubleshooting: Network administrators use reverse DNS to identify the source of traffic in logs (e.g., seeing
crawl-66-249-66-1.googlebot.cominstead of just an IP). - Security and Logging: Helps in verifying the identity of a connecting host.
How it works
Reverse DNS queries are made to special top-level domains: in-addr.arpa for IPv4 and ip6.arpa for IPv6. The IP address is reversed and appended to this domain before a DNS request for a PTR record is sent.
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