In Chapter 3, Troubleshooting a Web Application, we took an in-depth look at troubleshooting web applications; while we walked through a complex application error, we completely skipped the networking aspect of web applications. In this chapter, we will investigate a reported issue that will walk us through concepts such as DNS, routing, and of course network configuration for RHEL systems.
Networking is an essential skill for any Linux systems administrator. To quote a past instructor:
A server without a network is useless to everyone.
As a systems administrator, every server or desktop that you manage will have some sort of network connection. Whether this network connection is within a segregated corporate network or directly connected to the Internet, a network is involved.
Since networking is such a critical topic, this chapter will cover many aspects of networking and network connectivity; however, it will not cover firewalls. Firewall troubleshooting...