The Whois protocol allows for some information about the owner of a domain to be obtained. There is no single server that has all this information. Each Top Level Domain (.com, .co.uk .org etc) is assigned at least one organization to provide domain name registrations. It is the organization's responsibility to create and offer the WHOIS database. The Whois protocol is often used to offer access to the public by this database. They may however opt to only offer information in some other format such as a web site.
The trick to successful use of this service is to know which server to query. Ping-Probe contains a list of 179 domains and the servers that offer info for them. So most of the work is done for you. If the domain is in the list the server will be selected for you, as long as the option 'Attempt to locate Server' is checked in the advanced options. If you wish to manually enter a server then unselect this option. To add or alter the server automatically selected from a domain edit the Whois.txt file located in the installed directory. You will need to restart the program for the change to take effect.
Other Advanced options include the Time-Out (in seconds) and the port. Whois usually uses the TCP port 43.
Table 13.1. Advanced Whois Properties
| Attempt to Locate Server | Used to select whether or not the program should attempt to lookup the server to query for the domain. |
| Time-Out | How long, in seconds, to wait for a response from the server. |
| Port | The port to send the request to, usually port 43. |
| Enable Requery | With this enabled, if a response containing the text in the Marker is found, the text after the marker is taken to be a server and a second query to this new server will automatically be made. The query text for this new attempt will have a greenish background. |
| Requery Text Marker | Text indicating what identifies a requery server. This is all the text up to the server on the new line. This includes spaces. Internic, for example, will respond with ' Whois Server: whois.someserver.somewhere'. So here the marker would be ' Whois Server:' with 3 spaces before the text. |