Subnetting: What is subnetting in IPv4? (IPv4 subnets)

IPv4 subnetting explained:

IPv4 subnetting is a technique used to divide a larger IP address network into smaller subnetworks, or subnets. It is commonly used to make the most efficient use of available IP address space, improve network performance, and enhance network security.

Subnetting involves splitting a network address range into smaller address ranges or subnets, each with its own unique network ID and host range. This allows network administrators to assign IP addresses to devices based on their specific needs and ensures that each device has its own unique IP address.

To subnet an IPv4 network, the network administrator must first determine the network's IP address and subnet mask. The subnet mask is used to identify the network and host portions of an IP address. By changing the subnet mask, the administrator can create multiple subnets from a single network.

Once the subnet mask is determined, the administrator can use binary math to create the necessary subnets and assign IP addresses to devices within each subnet. The process involves determining the number of bits needed to identify the subnets and host IDs, calculating the number of subnets and hosts required, and then assigning IP addresses accordingly.

IPv4 subnetting is an important skill for network administrators and is commonly tested in IT certification exams such as the Cisco Certified Network Associate (CCNA) certification. There are many online resources and tools available to help individuals learn and practice IPv4 subnetting, including subnet calculators, practice exams, and tutorials.