Other than a networking how-to, one thing I'd like to suggest is a great little Perl script which will help you calculate network addresses. It's called ipcalc.pl, and can be downloaded from here: http://jodies.de/ipcalc.pl If you just type ./ipcalc.pl, it will explain the basic usage. Hope this helps. - Robert ================================================= bob@sonic:~/program> ./ipcalc.pl Usage: ipcalc [-n|-h|-v|-help] <ADDRESS>[[/]<NETMASK>] [NETMASK] ipcalc takes an IP 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. -n Don't display ANSI color codes -b Suppress the bitwise output -c Just print bit-count-mask of given address -h Display results as HTML -help Longer help text -v Print Version Examples: ipcalc 192.168.0.1/24 ipcalc 192.168.0.1/255.255.128.0 ipcalc 192.168.0.1 255.255.128.0 255.255.192.0 ipcalc 192.168.0.1 0.0.63.255