pfSense is open source router/firewall software based on the FreeBSD operating system. It provides a frontend to Packet Filter (PF), FreeBSD's built-in firewall. Originally introduced in 2006, it has achieved a level of scalability, flexibility, and cost-effectiveness that has made it one of the most popular router/firewall distributions. The flexibility of pfSense means that in most cases there are several options available when configuring options and services. In such cases, determining your specific requirements is critical to optimizing results.

This book tries to make this process of obtaining optimal results as easy as possible. It follows a cookbook-style approach to teach you how to use pfSense's many features after determining your security requirements. This book covers everything from configuring network interfaces and basic services such as DHCP and DNS, to more complex capabilities such as load balancing and failover.