LinuxCommandLibrary

whois

Lookup domain registration information

TLDR

Get information about a domain name

$ whois [example.com]
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Get information about an IP address
$ whois [8.8.8.8]
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Get abuse contact for an IP address
$ whois -b [8.8.8.8]
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SYNOPSIS

whois [options]

PARAMETERS

-h
    Specify the WHOIS server to query.

-p
    Specify the port number to connect to on the WHOIS server.

-q
    Specify the type of query (e.g., domain, referral).

-r
    Disable recursive lookups.

-t
    Specify the type of object to query for (e.g., domain, ip).

-v
    Display verbose output.

-H
    Hide legal disclaimers in output.

-c
    Read configuration from file

-i
    Show IP address information

-?
    Show help message.

-V
    Show version information.

DESCRIPTION

The whois command is a command-line utility used to query WHOIS (Who Is) servers. These servers maintain records about registered internet resources, such as domain names, IP addresses, and autonomous system (AS) numbers. When you execute whois with a domain name (e.g., example.com), it contacts the appropriate WHOIS server and retrieves information associated with that domain.

This information typically includes the registrant's contact details (name, address, phone number, email), administrative and technical contacts, the registration date, expiration date, name servers, and the registrar. whois is invaluable for identifying the owner of a domain, troubleshooting network problems, or verifying domain registration details.

Different WHOIS servers may present the data in slightly different formats, so the output might vary. Some registrars offer WHOIS privacy protection, which replaces the actual registrant information with a proxy service's details to protect their privacy. Due to GDPR and other privacy regulations, much of the personal data is now redacted, and you may have to contact the registrar directly for more information.

CAVEATS

WHOIS data may be inaccurate or outdated, especially due to privacy services. Many registrars implement rate limiting or other measures to prevent abuse of their WHOIS servers. Legal requirements like GDPR have significantly changed the availability of personal data.

REDACTED INFORMATION

Due to privacy regulations like GDPR, WHOIS output often contains redacted or anonymized information. To obtain more complete details, you may need to contact the registrar directly or utilize other methods.

INTERNATIONALIZED DOMAIN NAMES (IDNS)

WHOIS queries for IDNs (domain names containing non-ASCII characters) may require special handling or encoding.

HISTORY

The whois command has been around since the early days of the Internet. It was initially used to look up information about users and network administrators. Over time, its primary function shifted to querying domain registration information. The WHOIS protocol has evolved, and different implementations exist. The core functionality remains the same: querying a database to retrieve information about internet resources.

SEE ALSO

dig(1), host(1), nslookup(1)

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