Identify the IP Address and Required Subnet Mask

Start with the IP address: begin with the IP address you want to divide, such as 192.168.1.0.

Determine the number of subnets: if you need 4 subnets, decide on the appropriate subnet mask to accommodate them.

Calculate the Number of Subnets

Formula: use the formula 2^n - 2 where n is the number of bits borrowed from the host portion of the address to determine the number of subnets. For instance, borrowing 2 bits results in 4 subnets.

Determine Subnet Ranges

Assign subnet ranges: using the subnet mask, assign subnet ranges. If your original subnet mask is 255.255.255.0 and you need to create 4 subnets, your new subnet mask would be 255.255.255.192.

• 192.168.1.0 – 192.168.1.63 (Subnet 1)
• 192.168.1.64 – 192.168.1.127 (Subnet 2)
• 192.168.1.128 – 192.168.1.191 (Subnet 3)
• 192.168.1.192 – 192.168.1.255 (Subnet 4)

Configure Devices

Assign IP addresses: devices in the HR department could use addresses from 192.168.1.10 – 192.168.1.30 under Subnet 1 to ensure they are logically grouped.

Testing and Verification

Connectivity tests: after configuration, test connectivity to ensure devices within the same subnet can communicate, and verify isolation between subnets if required.

Document Your Subnets

Documentation: always document the subnet ranges, IP addresses, and configuration settings for future reference and troubleshooting.