The network operation mode is selected either at boot time
using askrunlevel (called automatically) or any time, using the
"netconf --runlevel" command.
Basically, Linux can operate in three different modes, network-wise.
- Standalone (local) mode.
This mode is selected when no network adapter
is installed. It might be selected to save
on RAM used.
This mode configures the loopback interface, allowing
you to do minimal "local" networking (which is a good
way to practice without bugging system administrators).
- Client mode.
In this mode, only the minimal daemons necessary
to access the network are started. While minimal,
inetd daemon is activated, allowing
your computer to provide some services, such as telnet.
- Server mode.
All daemons configured will be started.