IP Subnetting: An Overview 05/04/2023 – Posted in: Network – Tags: , ,

Time needed to read: 5 minutes

IP subnetting is the process of dividing a large network into smaller subnetworks, called subnets. This allows for better management of IP addresses and more efficient use of network resources. IP subnetting is a fundamental concept in computer networking, and it is important for network administrators and engineers to have a strong understanding of how it works.

When a network is first set up, it is given an IP address range, which is a block of IP addresses that can be used to assign to devices on the network. This IP address range is usually divided into smaller subnets, which are then assigned to different departments, floors, or groups within the organization.

The process of subnetting involves taking a portion of the host bits in the IP address and using them to create a separate network identifier. This network identifier is used to create the subnet mask, which is a binary number that determines which part of the IP address identifies the network and which part identifies the host.

For example, if an organization is given the IP address range 192.168.0.0/24, it means that they have 256 IP addresses to work with, ranging from 192.168.0.1 to 192.168.0.254. If the organization wants to create two subnets, they could divide the IP address range into two equal parts, with each subnet having 128 IP addresses to work with.

To do this, they would need to borrow one bit from the host portion of the IP address and use it as the subnet identifier. This would create a subnet mask of 255.255.255.128, which means that the first three octets (192.168.0) are used to identify the network, and the last octet is split into two parts: the first part identifies the subnet (either 0 or 128), and the second part identifies the host.

In this way, the organization could assign IP addresses in the range of 192.168.0.1-126 to one subnet and 192.168.0.129-254 to the other subnet. This allows them to separate the network traffic and better manage the IP addresses.

IP subnetting can become more complex when dealing with larger networks or when trying to create subnets with different sizes. However, the basic process remains the same: borrowing bits from the host portion of the IP address to create a separate network identifier, and using this identifier to create the subnet mask.

In summary, IP subnetting is a crucial concept in computer networking that allows for more efficient use of IP addresses and better management of network resources. By dividing a large network into smaller subnets, organizations can separate network traffic and better manage their IP addresses. Understanding how IP subnetting works is essential for network administrators and engineers.