parameter calculator for IPv4 addresses

 ipcalc takes an IPv4 address and netmask and calculates the resulting
 broadcast, network, Cisco wildcard mask, and host range. By giving a
 second netmask, you can design sub- and supernetworks. It is also
 intended to be a teaching tool and presents the results as
 easy-to-understand binary values.
 .
 Originally, ipcalc was intended for use from the shell prompt, but a
 CGI wrapper is provided to enable colorful HTML display through a
 webserver.
 You can find it in /usr/share/doc/ipcalc/examples directory.