Information:
GIPSC is an IP subnet calculator. There is a command line version (ipsc) and a GNOME version (GIPSC). You give the network class and subnet bits, and you get back the maximum number of subnets, maximum number of hosts per subnet, a bitmap showing the breakdown of network bits, subnet bits and host bits, the decimal and hexadecimal class netmask, and the decimal and hexadecimal subnet mask.