Chapter 10. Troubleshooting Network Issues

No network is perfect. Regardless of how well we plan and implement our infrastructure, problems can and will happen. The most important skill you will need in order to be successful as a network administrator is your ability to troubleshoot issues. When problems occur, your ability to think rationally and narrow down the issue by the process of elimination will carry you through. While it can certainly be stressful when things go haywire, network administrators enjoy the job security. In this chapter, we'll work through troubleshooting some common issues that may come up in Linux networks. In the final chapter of our journey, we will cover:

• Tracing routing issues

• Troubleshooting DHCP issues

• Troubleshooting DNS issues

• Displaying connection statistics with netstat

• Scanning your network with nmap and Zenmap

• Installing missing firmware on Debian systems

• Troubleshooting issues with Network Manager