Overview
This lecture explains Virtual Private Networks (VPNs), their role in network security, how they work, and their common uses in business.
Network Security Basics
- Businesses protect their networks using firewalls, NAT (Network Address Translation), and non-routable address spaces.
- Proprietary information and internal services require restricted access to authorized users.
Virtual Private Networks (VPNs)
- VPNs enable remote users to access private networks as if they were physically present.
- VPNs are commonly used for employees working from home or on business trips.
- VPNs establish a secure "tunnel" between the remote device and the company network.
How VPNs Work
- A VPN client creates a virtual interface with an internal IP address matching the company network.
- Data sent through this interface is encapsulated and encrypted inside transport layer packets.
- The VPN server removes outer layers, decrypts the data, and forwards it on the internal network.
- The process works both ways for two-way communication.
Security Features of VPNs
- VPNs require strict authentication to ensure only authorized users or computers connect.
- Two-factor authentication (2FA) is commonly used, requiring something beyond username and password (e.g., a temporary numerical token).
Site-to-Site VPNs
- Site-to-site VPNs connect entire networks (e.g., between separate office locations).
- Routers or specialized VPN devices establish the tunnel, allowing seamless resource sharing.
Key Terms & Definitions
- VPN (Virtual Private Network) — A technology that creates a secure, encrypted connection over a less secure network.
- Tunneling Protocol — A method of encapsulating network packets within other packets for secure transmission.
- Virtual Interface — A software-created network interface with a private network IP address.
- Two-Factor Authentication (2FA) — Security method requiring two forms of identification for access.
Action Items / Next Steps
- Review different VPN implementations and tunneling protocols as assigned reading.
- Prepare to discuss VPN use cases and security considerations in the next session.