network configuration
in-depth look at the network configuration files

in-depth look at the SSH configuration files, options, security best practices, etc

TCP wrappers
configuration of /etc/hosts.allow & /etc/hosts.deny for added security

DNS client
configuration of /etc/resolv.conf for DNS resolution

configuration of Virtual Network Computer remote desktop sessions

simple configuration of an LDAP client

time, chrony & ntp
date & time extraction/modification with timedatectl, date & hwclock and time synchronisation with chronyd & ntpd

networking tools

ip command
in-depth look at ip address, link route

netstat command
in-depth look at netstat and overview of its replacement ss

address resolution
in-depth look at nslookup, host, dig, arping whois

host alive?
in-depth look at ping, ping6 & hping3

tracing routes
in-depth look at traceroute, tracepath & tracepath6

packet sniffing
in-depth look at tcpdump

swiss army knife
in-depth look at netcat

messaging local users

in-depth look at wall