whois Linux command

The Linux whois command is a powerful networking tool used to retrieve domain name registration information, IP address assignments, and other related information. By querying the WHOIS database, users can access details about domain registrars, registration dates, name servers, and contact information. This command is essential for network administrators, web developers, and cybersecurity professionals to investigate domain ownership, troubleshoot network issues, and ensure compliance with internet regulations. The syntax typically involves running “whois” followed by the domain name or IP address. Additionally, the whois command offers various options to customize queries and narrow down search results. By mastering the whois command, users can gain valuable insights into the ownership and history of internet resources, making it a must-have tool for managing online assets and addressing network-related concerns.

whois Syntax:

whois [options] [parameters]

Options:

Option	Description
-h	Display usage information
-a	Do not query for IPv6 address
-p port	Connect to specified port
-r	Query without using network
-t type	Query regarding specified object type
-v	Display version information
-V	Show verbose information
-T	Output in terse mode

Parameters:

Parameter	Description
domain	Query information for the specified domain
nameserver	Query information for the specified name server
IP_address	Query information for the specified IP address

Caution

Exercise caution while using the whois command to query sensitive information. It is important to ensure that the usage of this command complies with legal regulations and organizational policies to prevent any misuse or unauthorized access to data.

whois bash Examples:

Check Domain Information

whois example.com

Retrieves and displays the WHOIS information for the domain name “example.com”.

Query IP Address Information

whois 8.8.8.8

Retrieves and displays the WHOIS information for the IP address “8.8.8.8”.

Find Registrar Information

whois -h whois.networksolutions.com example.com

Queries the WHOIS database at “whois.networksolutions.com” to find registrar information for the domain name “example.com”.

Retrieve Name Server Information

whois -h whois.verisign-grs.com example.net

Queries the WHOIS database at “whois.verisign-grs.com” to retrieve name server information for the domain name “example.net”.

Search for Country Code Top-Level Domain (ccTLD) Information

whois .uk

Retrieves and displays the WHOIS information for the country code top-level domain “.uk”.

Check Domain Availability

whois -h whois.verisign-grs.com mynewdomain.com

Checks the availability of the domain name “mynewdomain.com” by querying the WHOIS database at “whois.verisign-grs.com”.

Tip

When using the whois command in Linux, consider adding options to specify the desired output format, query specific servers, or enable/disable recursion for nested queries.

whois Command Help Center:

How do I use whois in Linux?

To use the whois command in Linux, execute the following command:

whois --option <value>

What is the purpose of the whois command in Linux?

The whois command in Linux is used to retrieve domain registration information from a WHOIS server.

How can I query a specific WHOIS server using whois in Linux?

To query a specific WHOIS server using whois in Linux, use the following command:

whois -h <WHOIS_server> <domain_name>

How can I search for a specific field in the WHOIS information using whois in Linux?

To search for a specific field in the WHOIS information using whois in Linux, you can grep the output for the desired information. For example:

whois <domain_name> | grep "Registrant Name"

How do I enable recursive WHOIS queries in Linux using whois?

To enable recursive WHOIS queries in Linux using whois, use the following command:

whois -r <domain_name>

How can I get brief WHOIS information using whois in Linux?

To get brief WHOIS information using whois in Linux, you can use the “-q” option. For example:

whois -q <domain_name>

How can I force a WHOIS query bypassing the local cache in Linux using whois?

To force a WHOIS query bypassing the local cache in Linux using whois, use the following command:

whois -c <domain_name>

How do I get information about the WHOIS command options in Linux?

To get information about the WHOIS command options in Linux, you can use the following command:

whois -h

Applications of the whois command

• Checking domain registration information
• Retrieving contact information for a domain owner
• Identifying the registrar of a domain
• Verifying domain availability
• Investigating IP address allocation and ownership information
• Finding out the expiration date of a domain
• Researching the name servers associated with a domain
• Locating technical and administrative contacts for a domain