Virtual Private Network!
Virtual private network or a VPN is a secured encrypted connection between two servers in WAN/MAN so that they can easily and securely communicate with each other over the internet.
A normal connection on the internet is very insecure and a user can face various issues while communicating. But in VPN, a secured encrypted tunnel is created between the two servers on the internet which makes the users feel like they are working on a LAN or private network.
Why use VPN?
As any company grows, it increases its business and branches in various places. Now if there is a problem in any one of its branches, the administrator/concerned authority will then have to personally go there and solve it. Or he can connect to the other branch via internet. This connection won’t be secure and anyone on the internet can view or get access to it.
If the firm is financially stable and has a lot of money, they can go for leased line. It is safe, reliable and secure, but very costly.
So here comes the main use of VPN, a VPN is as good as a lease line over internet but less costly. That is, it provides the same features like lease line, but it is much cheaper and easier to use.
VPN Real-Life scenario.
Here’s a scenario which will help you understand VPN very easily.
Take the ocean as an Internet, and Islands as various branches of your company. Now you’re on island A and for some reason you need to communicate with island B.
Now you have 3 choices to travel to island B (communicate with other branches over internet).
1. Using a boat/yacht (using normal connection):
Real-World: You can use a boat or a yacht. Now boat is open. Anyone in the ocean can view all the things you’re carrying! Even if you use a yacht, it can always be hijacked in the middle of the ocean and the goods can be manipulated or compromised.
Computer-World: You can connect to the other end via the internet and all your data will be available for others present on the internet. Eavesdropping and session hijacking can take place in this method.
2. Using an aero-plane (using lease lines)
Real-World:
You can then use an aeroplane to travel to the other island with your data. ou won’t be travelling on the internet, but it will cost you a lot of money.
Computer-World: Using lease lines is safe and reliable but it will cost you a lot!
3. Using a submarine (using a VPN)
Real-World:
We can then use a submarine which will easily take us from Island A to Island B securely over the ocean and no one present in the ocean will know about this. Also submarine will cost you less than an aeroplane and will have less problems.
Computer-World:
We can use a VPN which will use the internet and help us connect securely with the other branch and we can send or receive data in encrypted form!
VPN Working
Here’s how you connect to other machines on the internet:
Normal connection
Here’s how you work with VPN:
Connection with vpn
A VPN uses the public network that is the internet to communicate with the other network. For security, it creates a tunnel from the users side to the client’s side using tunneling protocols like L2TP (Layer 2 tunneling protocol) and PPTP. The communication is encrypted at the sender’s side and decrypted at the receiver’s side.
As a precautionary measure, the sender’s network address as well as the receiver’s network address are also encrypted.
So basically in a VPN, you have a tunnel which cannot be entered, if some hacker does manage to do that, all the data sent and received are in an encrypted form, plus the hacker won’t even know the sender’s or the receiver’s network address.
VPN tunnel
- Tunneling is a method used to transfer data from one network to other.
- The VPN tunnel consists of various routers all over the internet. It starts from the sender’s end and ends the receiver’s.
- When a frame enters the VPN tunnel, the tunneling protocol adds an additional header to the frame. This header gives the frame the routing information to the destination.
- Since the main motive of VPN is to offer a secure connection between the sender and receiver, the tunnel will break itself if it feels like someone is eavesdropping(listening) on it, and automatically find an alternative route to the receiver.
- Once the receiver’s network gets the frame, it first removes the header and then decapsulates the frame and sends it to the intended receiver’s machine.
- Moreover, all the communication doneps the sender and receiver feel like they’re connected in a Local Area Network and not the Internet. Both the sender and receiver feel they’re isolated from all other networks.
- The IP packets in the tunnel are encapsulated using the PPTP protocol, L2TP protocols for encryption.
- Communicating using VPN:
Communication using VPN
One of the main features of VPN is although it uses various routers to create a tunnel which will connect you to the destination, that tunnel is very secured. If it senses someone is trying to eavesdrop the tunnel, it will find a new route to the destination and use that.
For using VPN, you should have a very high upload speed (anything above 1 Mbps). Slow upload link usually makes the tunnel feel like it is under attack so it constantly tries to change its route making VPN connection very slow!