Reverse DNS Search
Batch Processing
Resolve multiple IPs with CIDR range support
Network Mapping
Identify host patterns and infrastructure setup
Security Validation
Verify legitimate servers and detect suspicious hosts
Common Questions
What is Reverse DNS Lookup?
Think of it like a phone book in reverse - instead of looking up a name to find a number, you're looking up a number to find a name. In this case, you're converting IP addresses into their corresponding hostnames, which is crucial for network troubleshooting and security analysis.
Why would I need to use Reverse DNS?
It's like having a security camera that not only shows you what's happening but also tells you who's who. You might need it to verify email server configurations, investigate suspicious network activity, or validate your network infrastructure setup.
What's the difference between DNS and Reverse DNS?
If DNS is like looking up a person's phone number in a directory, Reverse DNS is like looking up who owns a specific phone number. Regular DNS converts domain names to IP addresses, while Reverse DNS does the opposite - it converts IP addresses back to hostnames.
What formats can I use for IP ranges?
You can use several formats: Single IP (192.168.1.1), Short range (192.168.1.1-30 for IPs 1 through 30), Full range (192.168.1.1-192.168.1.30), or CIDR notation (192.168.1.0/24 for all 256 IPs in that subnet). Choose the format that's most convenient for your needs!
Why use range notation instead of CIDR?
Range notation (like 192.168.1.1-30) is often more intuitive and precise than CIDR. Instead of checking a full /24 network (256 IPs), you can target just the specific range you're interested in. This is perfect for checking a smaller subnet, a specific server range, or avoiding timeouts with large lookups.
Why do some IPs have no hostname?
Not every IP address has a hostname assigned to it, just like not every phone number is listed in the directory. This could be because the IP is private, not configured for reverse DNS, or intentionally left unassigned for security reasons.
Is there a limit to how many IPs I can look up?
Yes, for optimal performance we limit CIDR ranges to /24 or smaller (maximum 256 IP addresses at once). For larger datasets, we recommend splitting your query into multiple smaller ranges or using a more targeted approach. Starting with smaller ranges (20-50 IPs) is recommended for faster results.