In this chapter, we covered some troubleshooting fundamentals, including some basic steps you can employ in any troubleshooting scenario. We also covered some common networking problems and some troubleshooting tools you can use. Some of these tools, such as pfTop, are exclusive to pfSense/BSD, but many others, such as ping, traceroute, and netstat, can be found on multiple platforms, including Linux and Windows. Finally, we put these fundamentals into practice by considering a real-world VLAN configuration issue.

Needless to say, this chapter barely scratches the surface of network troubleshooting, and if you want to learn more about it, there are copious amounts of material available, both in book form and online. Of course, there is no substitute for practical experience, and there is a great deal you can learn from building and maintaining networks. Acquiring troubleshooting skills is something that will aid you not just in mastering pfSense, but in understanding networking in general.