Summary

We can't overstress the importance of fostering good troubleshooting habits by developing and practicing your own methodology, as we described at the beginning of the chapter. Follow the logical steps in the process of troubleshooting closelycollect symptoms, review recent changes, form a hypothesis, test the hypothesis, analyze the results, and repeat if necessary.

Also, don't forget to apply the rules of thumb when following these steps. Don't make multiple changes at one time as the actual solution for a problem can become unclear. Always keep an open mind when working on issues, let your troubleshooting process rule things out for you. When you get stuck, ask for a second opinion. Talking the problem out with someone else can help you find mistakes in your troubleshooting. Try to stay focused on the issue at hand. Don't implement a quick fix that may be more hazardous in the long run then the original problem. Remember not to overlook the obvious when considering the cause of your issue. Finally, try to keep strong documentation of your problems and their solutions so you don't have to "re-create the wheel" if you run into a similar issue in the future.

With those skills in place, however, your success will depend on knowing which tools to apply for a given problem. That's why we focused so heavily, in the remainder of the chapter, on describing some of our favorite tools and providing examples of their use. Use the knowledge you have gained of these tools, information on the layers that they apply to and the way they can be utilized to troubleshoot any networking security issue to your advantage when working through scenarios in your own environment. The combination of solid troubleshooting skills and the right tools for the job result in success at finding the right answers for any security problem scenario.