If I wanted my other departments to be in their own network?

Question

lets say I purchased a Ip iddress of 192.168.12.1 (I know I cant, But just go with it) If I had 10 departments (example marketing, Sales etc) that needed their own network with 20 hosts in each department, If they all wanted their own network within this network, what Ip address could I give them with what subnet masks that would work for this?

Answer 1

You can't do that with a single class C network block. The closest you can get is 8 networks of 30 hosts each (mask 255.255.255.224) or 16 networks of 14 hosts each (mask 255.255.255.240).

Answer 2

http://www.learntosubnet.com/