Whenever we hear this term VPN(Virtual private network) we think in a negative way like, VPN is not legal and it is only used by Hackers. The perception we have to this is completely wrong, VPN is not always using in the wrong way, Here in this article we will learn everything that is related to VPN technology.
Let us consider a scenario that a company has multiple branches in multiple places. Communication among those branches should be reliable and secure, If we tend to use a normal network that may or may not be secure. So, The solution for this problem is using a VPN.
A VPN is a private network which will use the public network generally internet to connect to other networks and websites. VPN uses the virtual connections to route the websites and clients using internet.
Before the VPN era, The most common way to create private networks is using the leased lines provided by ISP’s.These ISP’s allow people to connect using private networks using those leased lines and all these forms a wide area network which is secure but most expensive.
To solve this problem and create a virtual networks a new technology came into the picture that is INTRANET. This is the private network for a region and this provide many advantages like desktop sharing for the users and many more, The problem with this is they are constrained to one place. By using VPN we can extend Intranet to multiple locations ie, we can connect multiple Intranets using a VPN.
For example consider sky as the internet and we have two air crafts which provide you the resources and consider those two air crafts as LAN’s. When we want to use a resource from an aircraft you should travel along the internet, The problem here is you are visible to everyone. We can relate this to you connecting to a Web server. For an instance we created a bridge from our location to the aircraft we will be directly in link with the aircraft so it is more secure, We can relate this to you connecting using the leased lines, This will cost you more. Consider this scenario that you designed an invisible small aircraft and travel to resource aircraft in a route unknown to the others , You will be most secure. Relate this to you using a VPN, Think now you people understood what is VPN and how VPN gives you security.
How a VPN works technically??
A VPN will establish a secure connection privately from the public network to the remotely connected host.Using VPN we can secure our data by using encryption/decryption techniques and we can connect to any network around the globe.
Remote access VPN–
A remote access VPN allows the user to lay down a secure network path to the company network through the internet.The users can access all the resources from the server as they are directly connected to the network servers.Other name for this is VPDP(virtual private dial-up-network) as in the olden days network is established by dialing through telephonic lines.
The two components that make VPN are
1.Network access server(NAS)
2.Remote access VPN software at client side
Network access server or remote access server is the one which provides the resources and to which we need to connect through our VPN. This server needs a proper credentials to get into it.NAS will create tunnels.
Remote VPN software–
In order the client to access the server using a VPN he need to install VPN software in his machine and then he can access the NAS. Most of the operating systems today were giving VPN as a pre-installed application, When ever we install a VPN in our computer we are laying a secure tunnel to the server. This remote access VPN is used when there are less number of clients, What if there are dozens?? WE will use another VPN called Site to site VPN
Site to site VPN–
This VPN is used when there are many clients at different locations.
The main advantage of this VPN is every client need not to install seperate VPN softwares. Here two Intranets are connected using a VPN.
Tunneling in VPN–
VPN uses a technique called tunneling, Tunneling is a process of placing an entire data packet into another packet before it is transmitted over internet.The outer packet will protect the contents in the inner packet Layering of these packets called as encapsulation.
Top-3 free VPN’s–