New Training: Understanding IPv4 and Subnetting

In this 6-video skill, CBT Nuggets trainer James Conrad covers the binary nature of IPv4 and teaches you how to subnet. Watch this new Windows 10 training.

Watch the full course: Microsoft Windows 10

This training includes:

• 6 videos

• 47 minutes of training

You’ll learn these topics in this skill:

• IP Properties

• Understanding IPv4

• IPv4 Decimal to Binary

• Custom Subnet for Hosts

• Custom Subnet for Networks

• Custom Subnet for Larger Hosts or Networks

A Brief Explanation Of Subnets

Networks only have so much capacity. Network addresses are a finite resource. It is estimated that the entire global IPV4 address space has been used. So how are businesses able to create networks? This is a complicated question to answer.

First, networks are segmented into globally or uniquely available spaces. A public IP address can communicate with the outside world (Eg. A webserver). Private IP addresses are generally assigned to private networks, though. For example, the router in your home has a public IP address while the laptops in your house would have private IP addresses. Devices with private addresses can communicate with the outside world with protocols like NAT.

This gets further complicated with subnets. Subnets are a way to break up network space into segments. Segmenting a network space won't be an issue for your home but it can be for a business with thousands of devices.

There are three classes of subnets:

• Class A

• Class B

• Class C

Each subnet has a different limitation of addresses it can use. For instance, a Class C subnet only has access to 254 addresses.

Note that there are only 254 addresses available instead of 255. That's because one specific IP address is kept available for broadcasting typically, though this is not always the case.

Class A and Class B subnets have access to more IP addresses.

Devices on the same subnet can communicate with each other while devices on different subnets need some sort of bridge to pass along communications (like a router).

This is only an extremely brief summary of the IP address space and subnets. This article touches on a couple of topics with extremely large brush strokes. Segmenting networks with subnets is a much more in-depth topic.