Learning Objectives

By the end of this chapter, you should be able to:

• Explain what a Virtual Private Network (VPN) is and why organizations use it.
• Differentiate between Remote Access VPNs and Site-to-Site VPNs.
• Understand how VPN tunnels securely transmit data over public networks.
• Explain the role of encryption, authentication, and tunneling protocols in VPNs.
• Understand the fundamentals of IPSec.
• Compare OpenVPN and WireGuard.
• Differentiate between Split Tunneling and Full Tunneling.
• Explain how AWS Site-to-Site VPN and AWS Client VPN work.
• Understand how VPNs are used in hybrid cloud architectures.
• Troubleshoot common VPN connectivity issues.

Introduction

Imagine a company with its headquarters in Lagos and a branch office in London.

Employees in both offices need to securely access the same internal applications, databases, and file servers.

If the offices communicate directly over the public Internet without protection, attackers could potentially intercept sensitive information.

Instead, the company creates a private encrypted tunnel across the Internet.

Although the Internet is a public network shared by millions of users, the encrypted tunnel ensures that only authorized users can read the transmitted data.