Using a Virtual Private Network (VPN), a private network can securely extend across a public network, such as the Internet.

Usually, if a private network wants to extend, there are two ways it can do so :

• Using a dial-up or leased line connection that creates a physical connection to a port on a remote access server. This solution is very expensive.
• VPN creates an encrypted connection over an intermediate network, such as the Internet. Remote users can connect to remote computers using a VPN as if they are physically connected to the network.

How does a VPN work?

There are mainly two types of VPN :

• Remote Access VPN
• Site-to-Site VPN

In Remote Access VPN, a point-to-point connection is established between the user’s computer and the organization’s server. The VPN Client on the user’s computer connects to the organization’s network’s VPN gateway, and after proper authentication, a connection is established back to the remote user’s computer. The user can then access the internal network resources as if the user’s computer is connected to the network locally. Remote Access VPN often uses IPSec or SSL to secure the connection.

A VPN often uses a tunneling mechanism to transfer data securely. In tunneling, a network packet is encapsulated, added with another header, and sent across. The encapsulated packet travels through the network, and after reaching the destination network, it is decapsulated, and the payload is transferred to the final destination. The network packets are also encrypted to ensure security.

Several protocols can be used for tunneling. For example, a VPN can use Point-to-Point Protocol (PPP), Layer 2 Tunneling Protocol (L2TP), or Secure Socket Tunneling Protocol (SSTP) running across the base IPSec connection.

On the other hand, a Site-to-Site VPN uses a gateway device to connect the entire network from one location to the other. In this case, the gateway handles the VPN connections, so the end node does not need VPN clients.

Most Site-to-Site VPNs use IPSec, but they can also be created using Multiprotocol Label Switching or MPLS.

Privacy and Security and VPN

VPN cannot make online connections anonymous. All the VPN traffic goes through the VPN server. So, …