LPI Linux Certification in a Nutshell, 2nd Edition

Chapter 41. Network Troubleshooting (Topic 214)

This chapter covers the Topic of troubleshooting for the LPI 202 Exam. This Topic has one long Objective:

Objective 7: Troubleshooting Network Issues

Candidates should be able to identify and correct common network setup issues to include knowledge of locations for basic configuration files and commands. Key files, terms, and utilities include /sbin/ifconfig, /sbin/route, /bin/netstat, /etc/network and /etc/sysconfig/network-scripts, system log files such as /var/log/syslog and /var/log/messages, /bin/ping, /etc/resolv.conf, /etc/hosts, /etc/hosts.allow and /etc/hosts.deny, /etc/hostname and /etc/HOSTNAME, /sbin/hostname, /usr/sbin/traceroute, /usr/bin/nslookup, /usr/bin/dig, /bin/dmesg, and host. Weight: 1.

Notice that most of the commands and concepts discussed in these sub-Objectives have been covered elsewhere in this book. Chapter 19 covers most of the commands used in this chapter, and several other chapters discuss essential networking applications and daemons (services).

So, why discuss these things again? Because there is a difference between simply knowing what a daemon or command does and actually troubleshooting it. So, this chapter won't attempt to re-discuss options to the ifconfig command or the syntax for the /etc/hosts.deny files. Rather, it will focus on how to troubleshoot various services and how to use some of the commands you already know in an efficient way when problems occur.