Subnetting Steps (Number of Hosts and Subnets)
1. Draw the cutoff point according to the class
2. Convert the octets in the mask to binary (only the octets to the RIGHT of the
3. Count the number of 1’s and 0’s (to the right of the cutoff point)
4. Use the number of zero’s to determine the number of hosts per subnet
5. Use the number of one’s to determine the number of subnets.
Determining the actual subnet ID’s and the broadcast address of each subnet
1. Locate the furthest right octet in the subnet mask that is NOT a zero.
2. Subtract that number from 256.
3. This is the number you will count by as you determine subnet ID’s
4. Be careful to start your counting in the same octet as you determined in step 1
5. The broadcast address is the last valid address in each subnet (one way to find
this is to take the subnet ID of the next subnet, and determine the IP address
that comes before it)