Reverse DNS Lookup - Find All Domains on an IP
Discover every hostname pointing to a specific IP address. Reverse DNS lookup reveals shared hosting relationships, identifies all sites on a server, and exposes infrastructure connections invisible in forward DNS queries.
Why Reverse DNS Matters
Forward DNS maps domain names to IP addresses. Reverse DNS does the opposite - and reveals far more than you might expect.
When multiple domains point to the same IP, they share infrastructure. This might be intentional (a company's multiple brands) or indicate shared hosting where hundreds of unrelated sites coexist on one server.
What Reverse DNS Reveals
- All hostnames resolving to an IP - Every domain with A or AAAA records pointing to that address
- Shared hosting density - How many sites share the server
- Related domains - Patterns suggesting common ownership or infrastructure
- PTR records - The official reverse DNS entry configured by the IP owner
Security Applications
Shared hosting creates shared risk. If one site on a server is compromised, attackers may pivot to others. Reverse DNS lookup identifies your hosting neighbors.
For threat investigation, finding all domains on a suspicious IP reveals the scope of malicious infrastructure. Attackers often host multiple phishing sites or malware distribution points on single servers.
Technical Verification
Mail servers require matching forward and reverse DNS. If your MX record points to 192.0.2.1, that IP's PTR record should resolve back to your mail hostname. Reverse DNS lookup verifies this configuration.
Load balancers and CDNs complicate reverse DNS. An IP behind Cloudflare or AWS ELB will show many domains - this is expected behavior, not necessarily shared hosting.
Using Reverse DNS Data
Enter an IP address to see all hostnames pointing to it. Results are sorted by relevance, with PTR records and high-traffic domains prioritized.
Click any domain to see its complete DNS configuration. This bidirectional exploration - IP to domains, domains back to IPs - maps infrastructure comprehensively.