Troubleshooting Linux® Firewalls

Chapter 4. Troubleshooting Methodology

It’s important to use a systematic approach to solving firewall problems, much in the same manner that a systematic approach to risk management or network engineering is helpful when building a firewall. When troubleshooting, this is especially important in dealing with the increasingly complex world of networking and computing technologies we are required to support today. If you don’t rely on a logical method of isolating root causes and eliminating variables, you can find yourself wasting significant amounts of time repeating the same steps in your effort to resolve a troublesome issue, or you might even make the problem worse. The issue is further exacerbated by the increased dependency on networks over ...