Installing and Maintaining a Firewall Configuration

Why do we need a firewall? Besides the obvious, the Payment Card Industry (PCI) standard requires it; we need to reduce our risk by protecting our systems and networks from attempts to exploit known and unknown vulnerabilities.That all sounds fine for a formal response, but what are we really doing? We’re adding privacy to the internal network by restricting access to the systems on our internal network. A firewall is simply a noise filter or device that controls unwanted traffic into a company’s network from outside, and can play an important role by segregating sensitive areas from the rest of the company’s internal network.

Let’s take a look at firewall placement and configurations. Remember, this book isn’t meant to be an authority on firewalls, but it will give you some ideas. From time to time I’ll refer back to the PCI Self-assessment Questionnaire (SAQ) and/or the Security Audit Procedures to clarify.