Private, Public and Illegal IP Addresses

What is a Public IP address

Public IP Addresses (also known as Static IP Addresses) are IP addresses that are visible to the public.Because these ip addresses are public, they allow other people to know about and access your computer, like a Web server.In some cases, you do not want people to access your computer or you want to restrict certain individuals from accessing your computer or server. Basically if we want to access the internet we should need a public IP address.

What is a Private IP address

These addresses can be used on a private network, but they’re not routable through the public Internet. This not only creates a measure of much-needed security, but it also conveniently saves valuable IP address space. With a private address assainged to your pc you cannot access the internet.

Available Private Address

Class A – 10.0.0.0 through 10.255.255.255

Class B – 172.16.0.0 through 172.31.255.255

Class C 192.168.0.0 through 192.168.255.255

TIP – If your home or office pc is configured with a private IP address but still it might be able to connect to internet it is because NAT (Network Address translation) which is provided by the router.

What is an Illegal IP Address

Private networks that doesn’t have internet connections they can use any address they want,even public address. If  the organization later decides to connect to the Internet, its current address scheme might include addresses already assigned by the InterNIC (The Internet’s Network Information center) to other organizations. These addresses would be duplicate or conflicting addresses and are known as illegal addresses . Connectivity from illegal addresses to Internet locations is not possible.