Chapter 5, Network Troubleshooting, was all about networking and how to troubleshoot a misconfigured network. In this chapter, we are going to extend that discussion to firewalls. While troubleshooting firewalls we are likely to use some of the same commands as Chapter 5, Network Troubleshooting, and repeat a lot of the same process. This is because anytime you are using a firewall to protect a system, you are blocking certain types of network traffic, a misconfiguration of the firewall can impact any network traffic for a system.
We will start this chapter in the same way we did the other chapters, by troubleshooting a reported issue.