The following IP address ranges have been set aside for Internal use. These IP's are will not be routable on the Internet.
Class A:
10.xx.xx.xx
Addresses:
10.0.0.1 to 10.255.255.254
Class B:
172.16.xx.xx - 172.32.xx.xx
Addresses: 172.16.0.1 to
172.31.255.254
Class C: 1
92.168.xx.xx
Addresses: 192.168.0.1 to
192.168.255.254