Subnets – logical division of an IP network into several smaller segments. Organizations use them to divide large networks into smaller and more efficient subnets.
Why do we need subnets?
One of the goals of subnets is to divide a large network into a group of smaller interconnected networks to optimize traffic. Thus, traffic does not have to go through unnecessary routes, which increases the network speed. In addition, segmentation of the network address space increases the efficiency of IP address allocation.
How do subnets work?
Each subnet allows devices connected to it to communicate with each other. Routers are used to communicate between them. The size of the subnet depends on the communication requirements and the network technology used.
The point-to-point subnet makes it possible to connect two devices, while the data center subnet can be designed to connect many more devices.
Each organization is responsible for determining the number and size of subnets it creates within the usable address space. In addition, subnet segmentation details within the organization remain local.
The IP address consists of two fields: the network prefix (also called the network identifier) and the host identifier. What separates the network prefix and host ID depends on the address classification (A, B, or C). Example: 172.16.37.5 – IP address of IPv4 class B. Its network prefix is 172.16.0.0, host ID — 37.5.