Subnetting for Beginners
Source: Sudhian Media
In this guide we will be looking at how the home user can use subnetting when configuring his or her home network. Subnetting is useful when you have multiple devices that you need to network, but have been allocated only a single IP address from your internet service provider (ISP). For example, imagine you have just got a brand new cable modem, you've hooked it up, and you've been given an IP address by your ISP. However, you now have six computers and four network appliances and only one IP address. How do you do get all the devices online? Simple. Using a Private IP network and a router.
A Private IP Network uses any one of three sets of IP numbers set aside specifically for the use of anybody wishing to set up a private network that is not visible to other computers on the Internet. Our example of connecting multiple computers to one IP address is just such a case. These IP's are considered non-routable. In other words, even if you were connected directly to the Internet, rather than behind a router or a firewall, and you tried to surf the internet, you wouldn't be able to because no router in the world anywhere will route these IP addresses.
