VPN Security: Firewalls

A well-designed VPN uses several methods for keeping your connection and data secure:

• Firewalls
• Encryption
• IPSec
• AAA Server

In the following sections, we'll discuss each of these security methods. We'll start with the firewall.

A firewall provides a strong barrier between your private network and the Internet. You can set firewalls to restrict the number of open ports, what type of packets are passed through and which protocols are allowed through. Some VPN products, such as Cisco's 1700 routers, can be upgraded to include firewall capabilities by running the appropriate Cisco IOS on them. You should already have a good firewall in place before you implement a VPN, but a firewall can also be used to terminate the VPN sessions.