The NetworkManager applet should start automatically with the desktop environment. The applet is then shown as an icon in the system tray. Using the applet, choose a network to use explicitly at any time. Such a choice takes precedence over automatically selected networks. The chosen network is used as long as it is available. If it becomes unaccessible, NetworkManager automatically tries to connect to another available network.

If KNetworkManager is not running, start it with the command knetworkmanager. When it is running, an icon indicating the current network status is shown in the system tray. Depending on the state of the network connection, the panel icon changes appearance:

Right-clicking the icon opens the KNetworkManager menu with various options for managing network connections. See Figure 13.1, “Available Networks in the KNetworkManager Applet”. The menu contains available network connections for both wired and wireless devices. If you hold the mouse cursor over them, details about the connection are displayed. The currently used connection is checked in the menu.

Figure 13.1. Available Networks in the KNetworkManager Applet¶

13.1.1. Wireless Networks¶

The signal strength of wireless networks is shown in the menu. Encrypted wireless networks are marked with a lock icon. To connect to an encrypted network, choose it from the menu. In the dialog that opens, choose the type of Encryption the network uses and enter the appropriate Passphrase or Key.

	Hidden Networks
To connect to a network that does not broadcast its ESSID (Service Set Identifier) and therefore cannot be detected automatically, choose Connect to Other Wireless Network. In the dialog that opens, enter the ESSID and set encryption parameters if necessary.

To see all trusted and untrusted networks, click Options+Show Networks.

If you do not use NetworkManager but do use KDE, manage your Internet connections with KInternet. If KInternet is not installed by default, install the package kinternet with YaST. The program checks whether an Internet connection can be established. If this is possible, the KInternet icon, a plug, automatically appears in the right section of the KDE panel. Depending on the state of the network connection, the panel icon changes appearance:

Right-click the KInternet panel icon to access its configuration menu. Start the YaST configuration dialog with Settings+Configure with YaST. After entering the root password, YaST starts. Depending on the access type, start the modem, ISDN, network, or DSL configuration of YaST.

If you are using an ISDN connection and selected Channel Bundling in YaST, add a second ISDN channel to an existing connection with Add link. This doubles the transfer rate (although at a higher price). Activate channel bundling if you need to download large files. The activated channel bundling is evident from the red plus symbol at the top left corner of the KInternet icon.

If your computer has more than one network device and you have configured all of them with YaST, use the KInternet option Interface to switch between these interfaces. You must have selected User Controlled device activation in the appropriate YaST network dialog to do this. If you have multiple providers as well, choose them using Provider in KInternet. Providers are also set in YaST.

To establish Internet connections automatically, use dial on demand (DoD). If this mode is selected, KInternet automatically connects to your Internet service provider (ISP) as soon as a request is submitted. After a certain time-out, the connection is terminated. A DoD connection is evident from the blue D at the bottom right corner of the KInternet icon.

	Cost Control
Note that DoD only makes sense if you have a flat rate Internet account. If that is not the case, connecting and disconnecting all the time can become very costly.

To use a wireless network card as your connection to the Internet, configure it using YaST as described in Reference and make sure that the device activation in YaST is set to User Controlled. As soon as the interface is configured, you can use KInternet to control your wireless network connection.

To access the WLAN functionality of KInternet, right-click the icon to open the menu. Select Wireless Connection to open a window with two tabs. First, scan for suitable wireless networks to which to connect. Select the tab Scan for Wireless Networks and start the scan with Start Scan. For KInternet to continuously scan the network environment, also select Auto Refresh. Activate acoustic feedback for each connection found with Acoustic Scan. Any connection found is displayed in the list window. Select one and click Connect to connect to the selected network. If additional configuration efforts are needed to connect to the selected network, click Start YaST to launch the YaST network module for wireless network devices.

With the Current Connection tab, monitor the state of your current wireless connection. The left-hand view of this tab offers a summary of all connection parameters for network address and ESSID, signal quality, signal and noise level, channel frequency and speed, and encryption parameters, such as type of encryption and key length. Select any of these parameters in the tree structure to see the details displayed in the right part of the window.

Connection problems can occur. Methods for resolving and preventing these problems depend on the tool used.