nslookup helps you find information about domain names, such as their IP addresses or the domain name associated with an IP address. 

When troubleshooting network problems, the nslookup command is a valuable tool. Short for ’’name server lookup,’’ nslookup is used from the command line to query DNS servers for details like domain names and IP addresses. This helps diagnose and resolve DNS-related issues efficiently. 

Let us look at what nslookup is, its uses and how to use the nslookup command. 

What is nslookup? 

nslookup is a command-line tool to discover the IP address or DNS record of a specific domain name. It also assists an individual in finding the domain attached to an IP address. To use the tool, enter “nslookup” into the Command Prompt or Terminal.  

This tool is available in most operating systems, including Windows, macOS, and Linux. It queries DNS servers to resolve domain names to IP addresses and vice versa and can perform other DNS-related tasks such as querying specific record types (e.g., MX, PTR, TXT) and changing the DNS server used for the query. 

What is the use of nslookup? 

Nslookup is used by the administrators to troubleshoot server connections and for security purposes. People usually use nslookup to guard against phishing attacks. Also, the numeral 1 can be substituted by the lower-case.  

By doing this the attacker will make the unfriendly site look friendly and familiar, for example, xyz1info.com vs xyzIinfo.com. Admins make use of the nslookup to make sure that the security of a particular website or a page is up to date. 

It serves several purposes in networking and administration of the system such as: 

  • Nslookup helps you to diagnose issues related to DNS by querying DNS servers and further displaying the information about names of the domain, IP addresses and DNS records. 
  • Nslookup also provides you with information about a domain, such as its IP address, canonical name, mail exchange records and other DNS records.  
  • It also has the ability to perform reverse DNS lookups, which further translates an IP address into a domain name.  
  • You can use nslookup to test the responsiveness and accuracy of DNS servers by querying them directly. 

 How to Use the nslookup Command 

Mastering the nslookup command is essential for troubleshooting network connectivity and diagnosing DNS issues.  

Here is a guide to using nslookup. 

Basic Use: 

To use nslookup, you should: 

1.Open the command-line interface (CMD on Windows or Terminal on macOS/Linux). 

2.Type ‘nslookup’, followed by the domain name or IP address you want to query. 

3.Press Enter to execute the command and view the DNS information for the specified domain or IP address. 

Further, this command will return the corresponding IP address which is associated with the domain name. You can also input an IP address to retrieve the associated domain name. 

Querying Specific DNS Servers: 

You should also keep in mind that the nslookup queries the DNS server, which is configured on your system, by default. You can also specify a different DNS server query by adding it as an argument.  

Reverse DNS Lookup: 

The nslookup also supports the reverse DNS lookups. As discussed earlier, DNS lookups involve querying an IP address to extract its corresponding domain name. Below given is an example of how you can simply enter the IP address as an argument: 

This command will return the domain name which is associated with the IP address ‘8.8.8.8’, if it is available. 

Additional Options: 

Nslookup provides you with assorted options to refine your queries and obtain specific information. For example, you can query for specific types of DNS records, such as MX records for mail servers or TXT records for text-based information. Also, you can further allow the debug mode to display detailed information regarding the DNS queries and responses. 

Examples of nslookup Commands: 

Popular nslookup commands include the following: 

  • /name — queries the current name server for the specified name. 
  • /server name — sets the current name server to the server the user specifies. 
  • /root — sets the root server as the current server. 
  • /set type=x — specifies the type of records to be displayed, such as A, CNAME, MX, NS, PTR, or SOA. Specify ANY to display all records. 
  • /set debug — turns on debug mode, which displays detailed information about each query. 
  • /set recurse — tells the DNS name server to query other servers if it does not have the information. 
  • /exit — exits nslookup and returns the user to a command prompt. 

Nslookup has two modes which are interactive and noninteractive. If an individual is looking up only a single piece of data, then they should use noninteractive mode, similarly if an individual is looking up more than one piece of data, using interactive mode is a more precise choice. 

Nslookup sends a query to a DNS server to find information about a domain name. Depending on your system, this DNS server could be your local server, an intermediate server, or the root server for the entire DNS hierarchy. 

The nslookup command is valuable for both network administrators and troubleshooters. It provides a quick and effortless way to query DNS servers and obtain information about domain names, IP addresses and DNS records.  

By using the command, you can diagnose DNS-related issues, obtain domain information, perform reverse DNS lookups, and test DNS server responsiveness.