Question: What is Reverse DNS?
Answer: Reverse DNS is a method of determining the domain name associated with an IP address. It is the opposite of DNS, which finds the IP address associated with a domain name. According to Internet standards, every IP address should have a domain name, and each one should be reachable through a reverse DNS record.
When running a dedicated server, it is important to have reverse DNS setup, and many web hosting providers will set it up for you or even require it. Reverse DNS also comes in handy if you ever need to lookup a domain for security reasons. For example, if there is a suspicious IP address logging into your server or hitting your site multiple times, you can find out the domain and thus the owner of that domain through reverse DNS.
On Linux and other Unix-based systems, there is an easy-to-use tool called nslookup. If you want to find DNS information for an IP address, just enter “nslookup” followed by the IP address:
Reverse DNS can also be used to prevent people from spoofing your domain or IP address by requiring reverse DNS verification. A great tool for Reverse DNS lookup is MyIpTest.com.