Subnetting The Right Way

Subnetting can be a tricky thing to understand and learning how to subnet properly is critical to setup a correctly running network. When subnetting, the core things to learn are the terms that are used and we will cover deeper in this article.

Subnetting an IP address is important to the person designing the network, usually an engineer or high level administrator that wants to ensure the network will operate correctly. Many people have a hard time understanding subnetting and how it works. Before exploring those methods to actually get a subnet to work though, one must explore the building blocks.

The "IP" in IP address stands for Internet Protocol and is the communication agent that is used in every connected device or technology of the Internet. From your smartphone or desktop computer to website servers, everything needs an IP address to talk correctly. The IP address is made up of a 32-bit number that ranges from 0 to 4294967295.

In theory the Internet can contain approximately 4.3 billion unique objects when using IPv4. IPv6 looks to change this by allowing a superior number of connected devices on the Internet once the protocol is fully implemented.

The term subnet is a shortened concept for a "subnetwork" or "smaller network" inside of a larger one. The very bottom of a subnet in a larger network has no subdivisions inside of it and is what is known as a "single broadcast domain" or LAN. LAN stands for Local Area Network. Using this broadcast domain is where devices connected directly with an MAC address of other devices. Each MAC address is a unique number assigned to every Internet connected device to make it specifically identifiable.

To limit broadcast traffic and for other security reasons, many networks are designed using subnetting to separate one group of devices from another through a single octet. Subnets are not infinite and have a defined beginning number which is even and a ending number which is odd.

The beginning number of a subnet is the Network ID and the ending number is the Broadcast ID and neither are allowed for use in a network because they are reserved to be the hierarchy addresses responsible for communicating with other subnets correctly.

Understanding the concept of subnetting involves that you point a connection you wish to make to the proper Network ID and subnet mask. When this is done properly you will be able to transmit communication (data packets) to other devices on the subnet and each unique Broadcast ID involved in that subnet. This is an easy to understand way of what subnetting is and why it is used.