If you’re a system administrator, website owner, or simply curious about internet infrastructure, you’ve probably heard of the ‘whois’ command. This versatile tool allows you to uncover a wealth of information about domain names and IP addresses. If you’re using Ubuntu Linux, you might be wondering how to install ‘whois’ in Ubuntu.
In this blog post, we’ll dive into the world of ‘whois’. We’ll cover everything you need to know, including installation, basic usage, interpreting results, and some advanced use cases.
What is ‘whois’?
The ‘whois’ command is a powerful utility used to query databases that store registration information associated with domain names and IP addresses. In essence, it allows you to find out who owns a domain, when it was registered, when it expires, and other administrative contact details.
Why Use ‘whois’?
Here are some of the most common reasons to use the ‘whois’ command:
- Domain Availability: Check if a domain name you have in mind is already taken.
- Troubleshooting: When you’re facing issues with a website or online service, ‘whois’ can help you identify the correct points of contact for resolution.
- Security Research: Track down the owners of potentially malicious websites or IP addresses.
- Curiosity: Learn more about the websites and online services you interact with daily.
Installing ‘whois’ in Ubuntu
The good news is that installing ‘whois’ in Ubuntu is incredibly straightforward. Ubuntu and other Debian-based Linux distributions include the ‘whois’ package in their standard repositories. Here’s how to install it:
- Update Your Package Lists: Before installing any software, it’s always a good practice to make sure your system’s package lists are up-to-date. Open a terminal window and run the following command: Bash
sudo apt update - Install the ‘whois’ Package: Once the update is complete, install ‘whois’ using the ‘apt’ package manager: Bash
sudo apt install whois
That’s it! You’ve successfully installed ‘whois’ on your Ubuntu system.
Using the ‘whois’ Command
The basic syntax of the ‘whois’ command is as follows:
Bash
whois <domain_name_or_ip_address>
For example, to look up information about the domain “example.com”, you would type:
Bash
whois example.com
Interpreting ‘whois’ Output
The results of a ‘whois’ query can appear quite lengthy and a bit overwhelming at first. Let’s break down the most important sections:
- Registrar: The company where the domain was registered (e.g., GoDaddy, Namecheap).
- Registrant, Administrative, Technical Contacts: The details of the individuals or organizations associated with the domain. This information may be partially hidden for privacy reasons.
- Nameservers: The DNS servers responsible for translating the domain name into an IP address.
- Status: Indicates whether the domain is active, inactive, or has any special restrictions.
- Creation Date: The date the domain name was initially registered.
- Expiration Date: The date when the domain registration is set to expire.
Advanced ‘whois’ Usage
Beyond basic lookups, here are some additional tips for using ‘whois’:
- Specific Servers: Many large organizations operate their own ‘whois’ servers. You can force a query against a specific server using the following structure: Bash
whois -h <whois_server> <domain> - Searching by Partial Information: If you’re unsure of the full domain, you might be able to search using fragments. Some whois servers support partial lookups.
In recent years, due to privacy regulations like GDPR, the amount of publicly accessible information from ‘whois’ queries has been reduced.
You might find that some contact details are masked or redacted.
Read also: