[Day 5] 2. Types of VPN

1. Based on Network Architecture

1. Site-to-Site VPN

   • Connects entire networks securely over the internet (e.g., linking two office locations).
   • Enables communication between devices across both networks.

2. Dialup / Client / Remote-access VPN

   • Connects a single remote user to a private network securely.
   • Typically uses a client application on the user’s device to establish the connection.

2. Based on Configuration / Implementation

• Trusted VPN

  • These VPNs are provided and configured by ISPs (Internet Service Providers), with the ISP trusted for security.

  • Can be implemented at Layer 2 or Layer 3 of the OSI model.

  • Layer 2 VPN: Example: ATM Circuits (Asynchronous Transfer Mode)

  • Layer 3 VPN: Example: MPLS (Multiprotocol Label Switching) with BGP (Border Gateway Protocol)

• Secure VPN

  • Focuses on securing data transmission using various protocols, often configured by the user or a trusted technical person of the organization.
  • Common protocols:
    • IPsec (Internet Protocol Security)
    • L2TP (Layer 2 Tunneling Protocol)
    • SSTP (Microsoft Secure Socket Tunneling Protocol)

• Hybrid VPN

  • Combines features of both trusted VPNs and secure VPNs.
  • Uses the ISP’s infrastructure for trusted connectivity and adds security protocols for encryption and protection.
  • Typically utilizes Layer 2 or Layer 3 technologies with IPsec or SSL/TLS for secure data transmission.

Visual Representation:

!2. VPN.png

How VPN Works:

When a VPN connection is established, two virtual adapters are created inside the machines involved. These adapters help manage the encrypted traffic and maintain a secure connection between the user and the network.