Introduction Of VPN (Virtual Private Network)

A VPN, or Virtual Private Network, is a connection between two endpoints - a VPN Router, for instance – in different networks that allows private data to be sent securely over a shared or public network, such as the Internet. This establishes a private network that can send data securely between these two locations or Networks. This is done by creating a “tunnel”. A VPN tunnel connects the two PCs or networks and allows data to be transmitted over the Internet as if it were still within those networks. Not a literal tunnel, it is a connection secured by encrypting the data sent between the two Networks. VPN was created as a cost-effective alternative to using a private, dedicated, leased line for a private Network. Using industry standard encryption and authentication techniques - IPSec, short for IP Security - the VPN creates a secure connection that, in effect, operates as if you were directly connected to your local network. Virtual Private Networking can be used to create secure networks linking a central office with branch offices, telecommuters, and/or professionals on the road (travelers can connect to a VPN Router using any computer with
VPN client software that supports IPSec, such as SSH Sentinel.)

There are two basic ways to create a VPN connection:

•VPN Router to VPN Router
•Computer (using VPN client software that supports IPSec) to VPN Router

The VPN Router creates a “tunnel” or channel between two endpoints, so that data transmissions between them are secure. A computer with VPN client software that supports IPSec can be one of the two endpoints. Any computer with the built-in IPSec Security Manager (Microsoft 2000 and XP) allows the VPN Router to create a VPN
tunnel using IPSec). Other versions of Microsoft operating systems require additional, third-party VPN client software applications that support IPSec to be installed.

Note-:
VPN- Virtual Private Network.
IPSec-Internet Protocol Security
SSH- Secure Shell