Subnets At A High Level

A network can be divided into subnets, which may be isolated from each other. They also allow routers to route traffic more quickly.

IPv4 addresses

IPv4 addresses contain be split into two parts: The first part defines the network and the second part defines the host/machine.

There are different classes of networks – primarily A, B, and C but there are also D and E which are less common.

The number of bits that define the network and the host within an IPv4 address differ depending on the network class.

Class A networks allow for the most number of hosts, and IPv4 addresses in a Class A network use 24 bits to define the hosts. This means the number of hosts allowed is *around 2^24. Meanwhile, Class C networks allows for less hosts and only use 8 bits to define the host, which means the number of hosts allowed is *around 2^8.

*I still don’t completely understand the detail around why the maximum hosts is less than the largest number that can be represented by the number of available bits.