Reverse DNS: What Is It and How Does It Work?

Whenever you enter a domain name such as “” or “”, DNS discovers the exact IP address and gives you the result. DNS acts as the phonebook of the Internet, it makes the internet work and links the web browsers with the websites.

The purpose of this article is to answer all the questions you have related to reverse DNS lookup, what exactly it is, how it works and how to perform a reverse DNS lookup.

What is DNS lookup?

In DNS lookup, the DNS record is returned from the DNS server. The DNS translates domain names into IP addresses by performing a DNS lookup. The way you search for a number in a phonebook is exactly what happens with the DNS lookup and hence it is called a “DNS lookup”.

Important note- Preceding further, let me remind you that every single device has an IP address and this IP address is used to navigate to the destination page. However, you don’t type your IP address.

What are the kinds of DNS lookups?

There are two kinds of DNS lookup:

a) Forward DNS lookup- In forward lookup, domain names are translated to the IP address of a particular site name(Hostname). As we are humans and not computers, we can remember words easily as compared to numbers. It is not possible to remember the IP addresses of different sites.

b) Reverse DNS lookup- In reverse lookup (RDNS lookup), an IP address is translated to its domain name.

Now, let us discover reverse DNS lookup in more detail:

  1.  A reverse DNS lookup is a DNS request for the domain name related to a given IP address. An RDNS search involves searching domain name registries and registrars’ databases. The reverse DNS database of the Internet is rooted in the top-level domain .arpa.
  2. Although reverse DNS lookups are recommended by the Internet Engineering Task Force (IETF) guidelines, they are not a strict requirement because reverse lookups are not necessary for the internet to operate normally. Reverse DNS lookups are not generally used as a result.
  3. Reverse DNS records are kept in a specific zone as pointer (PTR) records.
  4. A pointer (PTR) record is requested from DNS servers during a reverse DNS lookup. An IPv4 or IPv6 address is mapped to the host’s canonical name via a PTR record. The lookup fails if there is no PTR record on the server.

How does reverse DNS lookup benefit you?

  1. Analytics. Instead of simply listing logs of IP addresses, reverse DNS helps give data that can be analysed by humans.
  2. The only system in the world that can assist you in browsing the internet is DNS. Maintaining DNS Servers has grown more crucial since the internet has become a fundamental component of society. The internet would not exist without them.
  3. An IP address can be set using a reverse IP lookup, which links a domain name to the actual IP address of the computer hosting the domain. The answers aid in classifying server susceptibilities and the virtual hosts that a web server serves.
  4. Effortless network interaction. The majority of enterprise management systems, r-commands, SMTP servers, and network backup solutions won’t cause you any trouble if you use reverse DNS. One of the basics for using several Internet protocols is RDNS.

How to manually perform reverse DNS lookups?

In this section, we will find out how to manually perform the reverse DNS lookup.

  1. Reverse DNS lookup on Windows: You can utilise “nslookup” command to check DNS. Open the CMD (command prompt) and run the below command:
    nslookup < IP Address >Replace < IP Address > Your IP address should be resolved.In the image below, an IP address of is reverse DNS looked up.
  2. Reverse DNS lookup on Linux: Open the command prompt and enter the following command. dig -x IP_ADDRESS

    With the dig command, replace IP_ADDRESS with the IP address you wish to resolve, and you’ll see the results of the DNS reverse lookup.
  3. Reverse DNS lookup on Mac: You can run the below command if you are using macOS. Replace IP_ADDRESS with the IP address you wish to resolve.  dig -x IP_ADDRESS A reverse lookup for domain name servers will be performed and the results will be displayed.Today you learned what reverse DNS is and how you can use it on Windows, Linux, and Mac.We hope you liked reading our article on reverse DNS, its types and how it works. However, we’d love to get your feedback on what works and what doesn’t. Have we forgotten anything? Would you like to see any further information on reverse DNS lookup?