What Is the IP Administrator WHOIS Information?

WHOIS (short for "who is") is a protocol used to query databases to find out ownership information for internet resources like domain names and IP addresses. In simple terms, when you use WHOIS, you are asking a public database, "Who is responsible for this IP address or domain?" The database then returns details like the owner's contact information and registration status.

Originally, WHOIS queries were performed using command-line tools, which are still popular among system administrators today. Now, there are also many user-friendly online tools with web interfaces that can simplify the process. Regardless of the tool, the underlying process is the same: they use the WHOIS protocol, typically over TCP port 43, to send a request to the server holding the registration data. This data is maintained by specific authorities responsible for managing internet resources.

At the top of this management hierarchy is the Internet Assigned Numbers Authority (IANA), which coordinates the global allocation of IP addresses and domain names. IANA delegates the management of IP address resources to five Regional Internet Registries (RIRs), each responsible for a specific part of the world:

• RIPE NCC (Réseaux IP Européens Network Coordination Centre): Responsible for Europe, the Middle East, and parts of Central Asia.
• APNIC (Asia-Pacific Network Information Centre): Responsible for the Asia-Pacific region.
• ARIN (American Registry for Internet Numbers): Responsible for the United States, Canada, and parts of the Caribbean.
• LACNIC (Latin America and Caribbean Network Information Centre): Responsible for Latin America and parts of the Caribbean.
• AFRINIC (African Network Information Centre): Responsible for Africa. Before AFRINIC was established, IP addresses for this region were distributed by APNIC, ARIN, and RIPE NCC.