nslookup | DNS Utilities

Nslookup is a command-line utility used to query the Domain Name System (DNS) for information about domain names and their corresponding IP addresses. It’s a valuable tool for network administrators and system engineers to troubleshoot DNS issues and gather information about specific domains.

Basic Usage:

1. Open a command prompt or terminal: On Windows, you can access the command prompt by searching for “cmd” in the Start menu. On macOS or Linux, open a terminal application.
2. Type nslookup: This will start the nslookup tool in interactive mode.

Enter a domain name: Type the domain name you want to query and press Enter. For example:

nslookup example.com

3. View the results: Nslookup will display information about the domain, including its IP address, DNS server used, and other relevant details.

Additional Commands:

Set a specific DNS server: Use the server command to specify a different DNS server to use for your queries. For example:
server 8.8.8.8

Perform a reverse lookup: Use the -type=PTR option to perform a reverse lookup, which translates an IP address into a domain name. For example:
nslookup -type=PTR 192.168.1.100

• Exit nslookup: Type exit to quit the nslookup tool.

Example:

C:\> nslookup example.com

Server: example.com

Address: 192.168.1.100

Non-authoritative answer:

Name: example.com

Address: 192.168.1.100

In this example, nslookup queries the DNS server for the domain “example.com” and returns its IP address.

Troubleshooting DNS Issues with Nslookup:

• Check DNS server configuration: Ensure that your computer or device is configured to use the correct DNS servers.
• Verify domain registration: Make sure the domain name is registered and has been properly configured with DNS records.
• Check for DNS propagation: If you’ve recently made changes to DNS records, it may take some time for them to propagate across the internet.
• Look for errors: Nslookup will often display error messages if there are issues with the DNS query.

By understanding the basics of nslookup, you can effectively troubleshoot DNS problems and gather information about domain names and their corresponding IP addresses.