The Book of PF, 3rd Edition

Chapter 6. Turning the Tables for Proactive Defense

In the previous chapter, you saw how you might need to spend considerable time and energy making sure that the services you want to offer will be available even when you have strict packet filtering in place. Now, with your working setup in place, you’ll soon notice that some services tend to attract a little more unwanted attention than others.

Here’s the scenario: You have a network with packet filtering to match your site’s needs, including some services that need to be accessible to users from elsewhere. Unfortunately, when services are available, there’s a risk that someone will want to exploit ...