How many hosts per subnet
This will show you how to work out how many hosts per subnet on a class C network
Let's say you have been given the subnet mask of 255.255.255.224
The first thing we need to do is change our mask to binary. If you do not know how to do this you should look at my other tutorial first which can be found Decimal to Binary
Now that you have converted your mask in to binary
224 = 11100000
Remember on a class C network the first 24 bits are owned by the network the last 8 bits are owned by the host.
So count the ammount of zero's "0" in the mask you will see there are 5 of them.
5 to the power of 2 = 32 - 2 = 30
So we have 30 hosts per subnet