Chapter 13. Virtual Private Networks

IN THIS CHAPTER

• VPN Review

• Tunneling

• IPsec

• L2TP

• Attacks Against VPNs

• Deploying VPNs in WLANs

After you have made the decision to implement wireless access for your network, it is important to secure the access point by requiring it to authenticate through a Virtual Private Network (VPN) . VPNs create encrypted channels to protect private communication over existing public networks. As we have shown throughout this book, wireless networks are vulnerable by default, so it is important to use VPNs as an additional safeguard.

A VPN solution requires a combination of tunneling, encryption, authentication, and access control. This chapter will review VPN technology and show how even this secure solution is vulnerable to attack. In addition, we will discuss how the VPN works in relation to the wireless access point.

The following are some key features of VPNs:

• Encrypt traffic either between two points or two entire networks

• Usually software-based (rather than hardware-based)

• Provide variable levels of encryption, militated largely by export restrictions