205.3 - Troubleshooting Network Issues

Weight: 4

Description: Candidates should be able to identify and correct common network setup issues, to include knowledge of locations for basic configuration files and commands.

Key Knowledge Areas:

Location and content of access restriction files

Utilities to configure and manipulate ethernet network interfaces

Utilities to manage routing tables

Utilities to list network states.

Utilities to gain information about the network configuration

Methods of information about the recognized and used hardware devices

System initialization files and their contents (SysV init process)

Awareness of NetworkManager and its impact on network configuration

Terms and Utilities:

ip

ifconfig

route

ss

netstat

/etc/network/, /etc/sysconfig/network-scripts/

ping, ping6

traceroute, traceroute6

mtr

hostname

System log files such as /var/log/syslog, /var/log/messages and the systemd journal

dmesg

/etc/resolv.conf

/etc/hosts

/etc/hostname, /etc/HOSTNAME

/etc/hosts.allow, /etc/hosts.deny