This protocol had its roots in the ARPANET NICNAME protocol. In other words, it was based on the FINGER/NAME protocol. Vic White and Ken Harrenstien had described the WHOIS protocol in RFC 812 in the year 1982. This was initially implemented on the NCP (Network Control Program), however found its prominent usage after the standardization of the IP/TCP suite.
Today, WHOIS services are generally communicated with the help of TCP or Transmission Control Protocol. Usually it is observed that the servers pay attention to the requests on port number 43. Besides, clients enjoy easy applications which pave way for a communications channel to the server and ensure transmitting a text record using the queried resource name. Next, you need to wait for the response that usually comes in a sequence of text records. You can access the database for the same. This protocol is simple to use that it allows a command line interface user and application to query a WHOIS server with the help of a Telnet protocol.
Formerly, WHOIS lookups were executed using a command line interface application. However, today a number alternative have come up from where you can make the needed selection. Generally speaking, a WHOIS database comprises an sequence of text records meant for each resource. Now, these text records further comprise of different information items pertaining to the resource itself.
Ideally, you should look for companies that support IP address WHOIS lookups for various registries. Additionally, also look for options that provide comprehensive registrant search. With reverse WHOIS, you can look for domain names that have been owned by various company or individual.
There are several websites that provide a basic WHOIS lookup service, however, make sure to go in for websites that provide extensive historical details including IP Address, WHOIS, Screenshot history, Registrar, and Name Server. When purchasing a domain from somebody, you may not be aware how authenticate it is. Hence, be sure to research the domain's history.
If DNS lookups as well as domain research are considered to be a common practice in the regime, then you can also be equally interested in professional membership. So, whether you want to go for whois histories or registrant alerts, the expanded toolset offers a wide array of present as well as historical domain details.
With the help of Reverse WHOIS you can explore other domains, which are owned by similar organization, research possible spammers as well as trademark violators.