In GNOME, NetworkManager can be controlled with the GNOME NetworkManager applet. If the network is set up for NetworkManager control, the applet usually starts automatically with the desktop environment and is shown as an icon in the system tray.
If your system tray does not show GNOME NetworkManager applet, the applet is probably not started. Press Alt+F2 and enter nm-applet to start it manually.
The current network status is shown in the system tray. The appearance of the icon depends on the state of the network connection. If you are not sure what the icon means, hold your mouse over the icon until an explanation appears.
A wired connection has been established.
Currently there is no connection to the Internet.
A wireless connection has been established. Blue bars indicate the strength of the signal. More blue bars means better signal strength.
The connection is being established or terminated.
NetworkManager distinguishes two types of connections: trusted and untrusted. A trusted connection is any network that you explicitly selected. All others are untrusted. Left-click the NetworkManager icon to show a list of connections that you have already used at least once in the past. The currently used connection is marked in the menu. To get information about the current connection (including the used interface, IP address, and hardware address), right-click the applet icon and choosefrom the menu.
Left-click the NetworkManager applet to choose another network connection at any time. Such a choice takes priority over automatically selected networks. The chosen network is used as long as it is available, meaning that plugging a network cable in does not switch to a wired network connection automatically.
Figure 10-2 Available Networks in GNOME NetworkManager Applet
NetworkManager also supports connections to 802.1X protected networks, the use of VPN connections, and UMTS/3G connections. Apart from using NetworkManager, you can also use UMTSmon to control UMTS connections as described at http://en.opensuse.org/Umtsmon.
GNOME NetworkManager applet offers several possibilities to configure network connections. For quick and easy configuration of a new wireless (ADHOC) network, proceed as described in Section 10.5.5, Configuring Your Wireless Card as an Access Point.
To access an advanced configuration dialog with which to configure and modify details for all types of connections, right-click the applet icon and select.
Thedialog shows tabs for all types of network connections, such as wired, wireless, UMTS (Mobile Broadband), DSL, and VPN connections.
To add a new connection, click the tab for the connection type you want to use and click. Enter your connection details and click . The newly configured network connection now appears in the list of available networks you get by left-clicking the NetworkManager icon.
When editing each connection, you can also define if NetworkManager should automatically use this connection or should use this connection systemwide.
If your computer is connected to an existing network with a network cable, use the NetworkManager applet to choose the network connection.
Left-click the applet icon to show a menu with available networks. The currently used connection is selected in the menu.
To switch to another network, choose it from the list.
To switch off all network connections, both wired and wireless, right-click the applet icon and uncheck.
Available visible wireless networks are listed in the GNOME NetworkManager applet menu under. The signal strength of each network is also shown in the menu. Encrypted wireless networks are marked with a shield icon.
To connect to a wireless network, left-click the applet icon and choose en entry from the list of available wireless networks.
If the network is encrypted, a dialog opens. Choose the type ofthe network uses and enter the appropriate .
To connect to a network that does not broadcast its service set identifier (ESSID) and therefore cannot be detected automatically, left-click the NetworkManager icon and choose.
In the dialog that opens, enter the ESSID and set encryption parameters if necessary.
To disable wireless networking, right-click the applet icon and uncheck. This can be very useful if you are on a plane or in any other environment where wireless networking is not allowed.
If your wireless card supports access point mode, you can use NetworkManager for configuration.
Add the network name and set the encryption in thedialog.
IMPORTANT: Unprotected Wireless Networks Are a Security Risk
If you set None, everybody can connect to your network, reuse your connectivity and intercept your network connection. To restrict access to your access point and to secure your connection, use encryption. You can choose between various WEP and WPA–based encryptions.to
If you do not want to enter your credentials anew each time you want to connect to an encrypted network, you can use GNOME Keyring Manager to store your credentials encrypted on the disk, secured by a master password. Whenever any GNOME application that uses GNOME Keyring needs to access passwords or credentials stored there, a check is made if the keyring is locked or not. If it is locked, you will be prompted for the master password to unlock the keyring. .