NetworkManager is the ideal solution for laptops and other portable computers. With NetworkManager, you do not need to worry about configuring network interfaces and switching between networks when you are moving.
However, NetworkManager is not a suitable solution for all cases, so you can still choose between the traditional method for managing network connections (ifup) and NetworkManager. If you want to manage your network connection with NetworkManager, enable NetworkManager in the YaST Network Settings module as described in Section “Enabling NetworkManager” (Chapter 5, Using NetworkManager, ↑Start-Up) and configure your network connections with NetworkManager. For a list of use cases and a detailed description how to configure and use NetworkManager, refer to Chapter Using NetworkManager (↑Start-Up).
Some differences between ifup and NetworkManager include:
root Privileges
If you use NetworkManager for network setup, you can easily switch, stop or
start your network connection at any time from within your desktop
environment using an applet. NetworkManager also makes it possible to change and
configure wireless card connections without requiring root
privileges. For this reason, NetworkManager is the ideal solution for a mobile
workstation.
Traditional configuration with ifup also provides some ways to switch,
stop or start the connection with or without user intervention, like
user-managed devices. However, this always requires root
privileges to change or configure a network device. This is often a
problem for mobile computing, where it is not possible to preconfigure
all the connection possibilities.
Both traditional configuration and NetworkManager can handle network connections with a wireless network (with WEP, WPA-PSK, and WPA-Enterprise access), dial-up and wired networks using DHCP and static configuration. They also support connection through VPN.
NetworkManager tries to keep your computer connected at all times using the best connection available. If the network cable is accidentally disconnected, it tries to reconnect. It can find the network with the best signal strength from the list of your wireless connections and automatically use it to connect. To get the same functionality with ifup, a great deal of configuration effort is required.
The individual network connection settings created with NetworkManager are stored
in configuration profiles. The system connections
configured with either NetworkManager or YaST can be found in
/etc/sysconfig/network/ifcfg-*. Any user-defined
connections are stored in GConf for GNOME or
$HOME/.kde4/share/apps/networkmanagement/* for KDE.
In case no profile is configured, NetworkManager automatically creates one and
names it Auto $INTERFACE-NAME. That is made in an
attempt to work without any configuration for as many cases as (securely)
possible. If the automatically created profiles do not suit your needs,
use the network connection configuration dialogs provided by KDE or GNOME
to modify them as desired. For more information, refer to
Section “Configuring Network Connections” (Chapter 5, Using NetworkManager, ↑Start-Up).
On centrally administered machines, certain NetworkManager features can be controlled or disabled with PolicyKit, for example if a user is allowed to modify administrator defined connections or if a user is allowed to define his own network configurations. To view or change the respective NetworkManager policies, start the graphical tool for PolicyKit. In the tree on the left side, find them below the entry. For an introduction to PolicyKit and details on how to use it, refer to Chapter PolicyKit (↑Security Guide).