jwhois is configurable via its configuration file, normally called jwhois.conf. This file is looked for in the sysconfdir that was specified when compiling the program (default is /usr/local/etc/ on most systems).
If no configuration file can be found, jwhois will default all queries to whois.internic.net.
An example configuration file that includes most known Whois servers can be
found in the
example subdirectory of the official distribution.
This example configuration also contains a lot of well used options
that should be suitable for most setups.
The configuration file is split into a number of blocks. Each block can contain a number of different options which are explained in the sections below. You can also get an overview of the syntax by looking at the example configuration file included in the distribution.