WHOIS

WHOIS (pronounced as the phrase who is) is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information. The protocol stores and delivers database content in a human-readable format. The WHOIS protocol is documented in RFC 3912.

History

When the Internet was emerging out of the ARPANET, there was only one organization that handled all domain registrations, which was DARPA itself. The process of registration was established in RFC 920. WHOIS was standardized in the early 1980s to look up domains, people and other resources related to domain and number registrations. As all registration was done by one organization at that time, one centralized server was used for WHOIS queries. This made looking up such information very easy.

Responsibility of domain registration remained with DARPA as the ARPANET became the Internet during the 1980s. UUNET began offering domain registration service; however they simply handled the paperwork which they forwarded to the DARPA Network Information Center (NIC). Then the National Science Foundation directed that management of Internet domain registration would be handled by commercial, third-party entities. InterNIC was formed in 1993 under contract with the NSF, consisting of Network Solutions, Inc., General Atomics and AT&T. The General Atomics contract was canceled after several years due to performance issues.

WHOIS++

The WHOIS++ protocol is a distributed directory system, originally designed to provide a "white pages" search mechanism to find humans, but which could actually be used for arbitrary information retrieval tasks. It was developed in the early 1990s by BUNYIP Information Systems and is documented in the IETF.

WHOIS++ was devised as an extension to the pre-existing WHOIS system. WHOIS was an early networked directory service, originally maintained by SRI International for the Defense Data Network. The WHOIS protocol is still widely used to allow domain ownership records in the Internet to be easily queried.

WHOIS++ attempted to address some of the short comings in the original WHOIS protocol that had become apparent over the years. It supported multiple languages and character sets to help with I18N issues, had a more advanced query syntax, and the ability to generate "forward knowledge" in the form of 'centroid' data structures that could be used to route queries from one server to another. The protocol was designed to be backward compatible with the older WHOIS standard, so that WHOIS++ clients could still extract meaningful information from the already deployed WHOIS servers.