In this chapter, we introduced you to the world of firewall rules and NAT. We briefly discussed some basics of firewalls, including pfSense’s default behavior, and also mentioned firewall best practices and why both ingress and egress filtering are a good idea. We walked through the process of creating firewall rules, and also introduced some example rules. Finally, we discussed NAT. The form of NAT you are most likely to use is port-forwarding, but we also briefly discussed Outbound NAT and 1:1 NAT.
You will want to review this chapter if you haven’t fully grasped the concepts discussed within it, as the next chapter builds heavily on what was covered here. We will discuss traffic-shaping in the next chapter, which, to a large degree, relies on firewall rules.