whois
Query domain and IP registration information
TLDR
SYNOPSIS
whois [options] object
DESCRIPTION
whois queries databases for domain name registration information, IP address allocation, and autonomous system (AS) numbers. It provides details about domain ownership, registration dates, name servers, and contact information.For domain names, whois contacts the appropriate registry (based on TLD) to retrieve registration data. For IP addresses, it queries regional internet registries (ARIN, RIPE, APNIC, etc.).The data returned includes registrant information (often privacy-protected), registration and expiration dates, name servers, and registrar details.Different registries have different data formats and levels of detail. Some domains use privacy services that mask the actual registrant information.
PARAMETERS
-h host, --host host
Query the specified WHOIS server instead of guessing it from the object.-p port, --port port
Connect to the given TCP port (default: 43).-H
Hide the legal disclaimers that some registries show.-r
Disable recursive lookups for contact information (RIPE-style servers).-I
Query whois.iana.org first and then follow its referral.-a
Also search all the mirrored databases (RIPE).-T type
Restrict the search to objects of the given type (e.g. inetnum, person).-B
Disable object filtering; include e-mail addresses in results.-R
Disable following referrals; show the object from the local copy.--verbose
Verbose output; show which server is being queried.
CAVEATS
Many domain registrations now use privacy protection services, showing proxy information instead of actual registrant details.Rate limits may apply. Excessive queries can result in temporary blocks from WHOIS servers.Data format varies significantly between registries. Parsing WHOIS output programmatically is challenging.RDAP (Registration Data Access Protocol) is gradually replacing WHOIS with a structured, standardized format.
