With 1.13 billion websites online, it’s challenging to sort and store connection details for each of them. Although an IP (Internet Protocol) address connects websites and servers, it takes time to keep track of this huge number of strings. 

This is where DNS (Domain Name Systems) records and Nslookup come in! The nslookup is a command line network tool for querying DNS records to get domain names or IP address mapping. 

Available on multiple operating systems, such as Linux, Windows, and macOS, nslookup is an effective resource for performing server testing and troubleshooting various DNS issues. 

In this post, we’ll learn more about nslookup, including what it is, how it works, how to use the nslookup command, its purpose, and the most common nslookup commands. 

What is Nslookup? 

Nslookup, or name server lookup, is robust network administration command-line software that queries the domain name system (DNS) to obtain domain names or IP addresses. Put simply, nslookup is a command to perform DNS queries and receive domain names or IP addresses.  

This command can also be used for reverse DNS lookups by entering the IP addresses of the domains. Additionally, the command offers various helpful options using underlying Internet protocol and other similar networking tools. 

How Does the Nslookup Command Work? 

The nslookup command works by sending all network queries to DNS servers to get useful information about IP addresses, domain names, and other DNS records. The process works as below: 

  • As soon as you enter any command in nslookup (type=a, -type=mx, -type=ns,-type=any,  or -type=ptr), the tool sends a DNS query to the server mentioned by the user. 
  • After receiving the query, the server processes it and responds with the needed information, such as the domain name or IP address associated with a particular domain name. 
  • The nslookup command then uses the DNS protocol to communicate with DNS servers and analyse the responses received from DNS servers. 

This will help users troubleshoot DNS issues, collect information about domain names, and identify network-related issues, if any. 

What Is the Purpose of the Nslookup Command? 

Nslookup retrieves detailed information about specific domains and their respective servers. Here are other ways you can use the nslookup command: 

1. Searching Domains’ IP Addresses 

Nslookup is the easiest and quickest way to find an IP address for a domain. You can either use it to look up specific IP addresses for troubleshooting network issues or to find a specific domain you wish to block or unblock. 

READ: How to Check Domain Name Ownership and Find Domain Owner History 

2. Finding Suspicious Domains 

Another use of the nslookup command is to find suspicious or harmful domains. One example is a web address specifically designed to copy an existing domain, for instance, missio1n.com, instead of mission.com. 

3. Searching Optimal Mail Servers 

The nslookup tool also searches the best email server for your website. For instance, by using the settype=mx nslookup command, you can search for mail exchange records for your domain name. These records will give specific server names and IP addresses for reference when setting up your mail servers. 

READ: Elevate Business Communication with Email Hosting powered by Titan 

4. Resolving Issues Related to the DNS Server 

Nslookup can also identify and resolve issues with your host server and DNS server.  

For instance, if the website is loading slowly or has a problem with your directory, nslookup can help you identify and fix an unresponsive DNS server. Likewise, if the server isn’t online, you’ll get an error message and can start troubleshooting accordingly. 

READ: What is DNS – A Layman’s Guide to Understand the Domain Name System 

Commonly Used Nslookup Commands 

Below are some of the common nslookup commands you can use: 

  • Name Server (NS): Shows information about various primary and secondary domain names or hostnames using default servers for the domain. 
  • Address (A) Record: This nslookup command lists all the IP addresses of the domain where there is a separate address record for each. 
  • Text (TXT) Record: A TXT record nslookup command contains notes about the domain. System administrators use this command to verify ownership and prevent spam. 
  • Mail Exchange (MX): This nslookup command gives information about the mail servers within a domain name. 
  • Canonical Name (CNAME) Record: The command lists any aliases for the host. 
  • Start of Authority (SOA): An SOA nslookup record highlights the most authoritative host. 
  • Pointer (PTR) Record: This nslookup record supports easy reverse lookups of domains and lists the hostname associated with an IP address. 

Address Your DNS Issues Effectively with Nslookup 

The nslookup command tackles various DNS issues and retrieves important DNS, mail exchange, address, and other records. 

Overall, by leveraging nslookup commands and information, IT administrators and other network professionals can gain better insights into the DNS infrastructure and resolve various DNS-related problems efficiently.