Address (Host or Network) Netmask (i.e. 24) Netmask for sub/supernet (optional)
/ move to:
  



Address:   217.43.238.230        11011001.00101011.11101110.111001 10
Netmask:   255.255.255.252 = 30  11111111.11111111.11111111.111111 00
Wildcard:  0.0.0.3               00000000.00000000.00000000.000000 11
=>
Network:   217.43.238.228/30     11011001.00101011.11101110.111001 00 (Class C)
Broadcast: 217.43.238.231        11011001.00101011.11101110.111001 11
HostMin:   217.43.238.229        11011001.00101011.11101110.111001 01
HostMax:   217.43.238.230        11011001.00101011.11101110.111001 10
Hosts/Net: 2

Thanks to http://www.netzwerkinfo.de/daemons/ for this ip calculator icon :-)
Version 0.35.2 2005/07/07
Download
07/27/2006 Security information
Screenshot (ipcalc works also at the prompt)
CGI wrapper that produced this page.
Archive
Have a look in the archives for the new version 0.41, with the capability to deaggregate network ranges
How to run this under windows
Debian users can apt-get install ipcalc
2000-2006 Krischan Jodies