IP Subnetting

IP subnetting is a technique that allows a network administrator to divide a large IP network into smaller subnetworks, called subnets. Subnetting is useful for several reasons, including:

Improving network performance: By dividing a large network into smaller subnets, network traffic can be reduced, which can improve network performance.

Enhancing network security: Subnetting allows network administrators to apply security policies and access controls to specific subnets, which can help to protect sensitive information and prevent unauthorized access.

Maximizing address space: By using subnetting, network administrators can make more efficient use of their IP address space.

In IP subnetting, the network administrator borrows bits from the host portion of the IP address to create a subnet mask, which is used to divide the network into smaller subnets. The subnet mask determines which bits of the IP address represent the network portion and which represent the host portion.

For example, if an organization has been allocated the IP address 192.168.0.0/24, which is a Class C network, they can subnet this network into smaller subnets by borrowing bits from the host portion of the IP address. If they borrow 3 bits, they can create 8 subnets, each with a network address of 192.168.0.0/27. The remaining 5 bits are used to identify hosts on each subnet, which allows each subnet to have up to 30 hosts.

Subnetting can be complex, especially for larger networks. There are many subnetting calculators available online that can help network administrators calculate the appropriate subnet mask and network addresses for their network.