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Applies to SUSE Linux Enterprise Server 11 SP4

27 Using NetworkManager

NetworkManager is the ideal solution for laptops and other portable computers. It supports state-of-the-art encryption types and standards for network connections, including connections to 802.1X protected networks. 802.1X is the IEEE Standard for Local and Metropolitan Area Networks—Port-Based Network Access Control. With NetworkManager, you need not worry about configuring network interfaces and switching between wired or wireless networks when you are moving. NetworkManager can automatically connect to known wireless networks or manage several network connections in parallel—the fastest connection is then used as default. Furthermore, you can manually switch between available networks and manage your network connection using an applet in the system tray.

Instead of only one connection being active, multiple connections may be active at once. This enables you to unplug your laptop from an Ethernet and remain connected via a wireless connection.

27.1 Use Cases for NetworkManager

NetworkManager provides a sophisticated and intuitive user interface, which enables users to easily switch their network environment. However, NetworkManager is not a suitable solution in the following cases:

  • Your computer provides network services for other computers in your network, for example, it is a DHCP or DNS server.

  • Your computer is a Xen server or your system is a virtual system inside Xen.

27.2 Enabling or Disabling NetworkManager

On laptop computers, NetworkManager is enabled by default. However, it can be at any time enabled or disabled in the YaST Network Settings module.

  1. Run YaST and go to Network Devices › Network Settings.

  2. The Network Settings dialog opens. Go to the Global Options tab.

  3. To configure and manage your network connections with NetworkManager:

    1. In the Network Setup Method field, select User Controlled with NetworkManager.

    2. Click OK and close YaST.

    3. Configure your network connections with NetworkManager as described in Section 27.3, “Configuring Network Connections”.

  4. To deactivate NetworkManager and control the network in the traditional way:

    1. In the Network Setup Method field, choose Traditional Method with ifup.

    2. Click OK.

    3. Set up your network card with YaST using automatic configuration via DHCP or a static IP address. Alternatively, configure your modem with YaST:

      • For dial-up connections, use Network Devices › Modem.

      • To configure an internal or USB ISDN modem, select Network Devices › ISDN.

      • To configure an internal or USB DSL modem, select Network Devices › DSL.

      Find a detailed description of the network configuration with YaST in Section 22.4, “Configuring a Network Connection with YaST” and Chapter 19, Wireless LAN.

27.3 Configuring Network Connections

After having enabled NetworkManager in YaST, configure your network connections with the NetworkManager front-ends available in KDE and GNOME. The network configuration dialogs for both front-ends are very similar. They show tabs for all types of network connections, such as wired, wireless, mobile broadband, DSL, and VPN connections. On each tab, you can add, edit or delete connections of that type. In the KDE configuration dialog, the appropriate tabs are only active if the connection type is available on your system (depending on hardware and software). By default, KNetworkManager also displays comprehensive tool tips for the input fields and options available on each tab.

Note
Note: Bluetooth Connections

Currently, Bluetooth connections cannot be configured with NetworkManager.

To open the network configuration dialog in GNOME, open the main menu and click the Network entry at the right. Alternatively, press AltF2 and enter nm-connection-editor or select System › Network Connections in the GNOME Control Center.

GNOME Network Connections Dialog
Figure 27.1: GNOME Network Connections Dialog

If you use KDE, open the main menu and click Configure Desktop. In the Personal Settings, select Network Settings (on the General tab) to open the network configuration dialog.

KDE Network Configuration Dialog
Figure 27.2: KDE Network Configuration Dialog

Alternatively, you can also start the configuration dialogs from the NetworkManager applet in the system tray. In KDE, left-click the icon and select Manage Connections. In GNOME, right-click the icon and select Edit Connections.

Note
Note: Availability of Options

Depending on your system set-up, you may not be allowed to configure connections. In a secured environment, some options might be locked or require root permission. Ask your system administrator for details.

Procedure 27.1: Adding or Editing Connections

When configuring network connections with NetworkManager, you can also define system connections that can be shared by all users. In contrast to user connections, system connections are made available right after NetworkManager is started—before any users log in. For more details about both types of connections, refer to Section 27.7.1, “User and System Connections”.

Currently, the system connection option is not available in KDE. To set up system connections, you need to use YaST in this case.

Note
Note: Hidden Networks

To connect to a hidden network (a network that does not broadcast its service) you have to know the Service Set Identifier (SSID) or Extended Service Set Identifier (ESSID) of the network. Hidden networks cannot be detected automatically.

  1. In the network configuration dialog, click the tab for the connection type you want to use.

  2. Click Add to create a new connection or select an existing connection and click Edit.

  3. Enter a Connection Name and your connection details.

  4. For a hidden network, enter the ESSID and the encryption parameters.

  5. You can tie the connection to a certain device, if more than one physical device per connection type is available (for example, your machine is equipped with two ethernet cards or two wireless cards).

    If you use KDE, do so by using the Restrict to Interface option. If you use GNOME, enter the MAC address of the device you want to tie the connection to and confirm your settings.

  6. For NetworkManager to automatically use a certain connection, activate the following option for this connection: Connect Automatically (KDE) or Stay connected when possible (GNOME).

  7. To turn a connection into a system connection activate Available to all users (GNOME). To create and edit system connections, root permission is required.

After having confirmed your changes, the newly configured network connection appears in the list of available networks you get by left-clicking the NetworkManager applet.

KNetworkManager—Configured and Available Connections
Figure 27.3: KNetworkManager—Configured and Available Connections

27.4 Using KNetworkManager

The KDE front-end for NetworkManager is the KNetworkManager applet. If the network has been 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 any network connection icon, the applet is probably not started. Press AltF2 and enter knetworkmanager to start it manually.

KNetworkManager only shows wireless networks that you have configured a connection for. It hides connections when you are out of range of a wireless network, or when the network cable is disconnected, thus always giving you a clear view of which connections may be used.

27.4.1 Managing Wired Network Connections

If your computer is connected to an existing network with a network cable, use KNetworkManager to choose the network connection.

  1. Left-click the applet icon to show a menu with available networks. The connection currently being used is selected in the menu and marked as Active.

  2. If you want to use a different configuration with the wired network, click Manage Connections and add another wired connection as described in Procedure 27.1, “Adding or Editing Connections”.

  3. Click the KNetworkManager icon and select the newly configured connection to activate it.

27.4.2 Managing Wireless Network Connections

By default, KNetworkManager only shows wireless networks that you have configured a connection for—provided they are both available and visible. To connect to a wireless network for the first time, proceed as follows:

Procedure 27.2: Connecting to a Wireless Network
  1. Left-click the applet icon and select Create Network Connection. KNetworkManager shows a list of available visible wireless networks, including details about signal strength and security.

  2. To connect to a visible network, select the network from the list and click Connect. If the network is encrypted, a dialog opens. Choose the type of Security the network uses and enter the appropriate credentials.

  3. To connect to a network that does not broadcast its service set identifier (SSID or ESSID) and therefore cannot be detected automatically, select Connect to Other Network with WLAN interface.

  4. In the dialog that opens, enter the SSID or ESSID and set encryption parameters, if necessary.

  5. Confirm your changes and click OK. NetworkManager now activates the new connection.

  6. To terminate a connection and to disable wireless networking, click the applet icon and uncheck Enable Wireless. This can be useful if you are on a plane or in any other environment where wireless networking is not allowed.

A wireless network that has been chosen explicitly will remain connected as long as possible. If a network cable is plugged in during that time, any connections that have been set to Connect Automatically will be connected, while the wireless connection remains up.

27.4.3 Configuring Your Wireless Card as an Access Point

If your wireless card supports access point mode, you can use NetworkManager for configuration.

Note
Note: Availability of Options

Depending on your system setup, you may not be allowed to configure connections. In a secured environment, some options might be locked or require root permission. Ask your system administrator for details.

  1. Click the KNetworkManager applet and select Create Network Connection › New Ad-Hoc Network.

  2. In the following configuration dialog, enter a name for your network in the SSID field.

  3. Set the encryption on the Wireless Security tab.

    Important
    Important: Unprotected Wireless Networks Are a Security Risk

    If you set Security to 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. If you are not sure which technology is best for you, read Section 19.3, “Authentication”.

  4. On the IP Address tab, make sure the Configure option is set to Shared (which is the default option for ad-hoc networks).

  5. Confirm your configuration with OK.

27.4.4 Customizing KNetworkManager

You can customize some aspects of KNetworkManager: the number of icons displayed in the system tray, which tool tips to show and how to store your password and credentials for network connections. For more information about the last aspect, refer to Section 27.7.2, “Storing Passwords and Credentials”.

To explore the options available, right-click the NetworkManager system tray icon, select Manage Connections and click Other on the left-hand side of the configuration dialog.

Procedure 27.3: Configuring Multiple Tray Icons for KNetworkManager

As KNetworkManager can keep multiple connections active at once, you might wish to be informed about the connection status for several connections at one glance. You can do so by using multiple NetworkManager icons in your system tray, each representing a different group of connection types (for example, one icon for wired connections, another icon for wireless connections).

  1. In the configuration dialog, switch to the Tray Icon tab.

  2. Click More Icons. A new icon entry appears in the list.

  3. Select the network connection types you want to be represented by this icon and group them under the respective icon.

  4. Confirm your changes.

Now the system tray shows multiple NetworkManager icons from which you then can access the connection types tied to that icon.

When configuring a network connection as described in Procedure 27.1, “Adding or Editing Connections”, KNetworkManager also allows you to customize the icon displayed for this connection. To change the icon, click the icon button next to Connection Name and in the following dialog, select the icon of your choice. After confirming your changes, the new icon is displayed in the list of available connections you get by clicking the KNetworkManager icon in the system tray.

27.5 Using the GNOME NetworkManager Applet

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 any network connection icon, the applet is probably not started. Press AltF2 and enter nm-applet to start it manually.

27.5.1 Managing Wired Network Connections

If your computer is connected to an existing network with a network cable, use the NetworkManager applet to choose the network connection.

  1. Left-click the applet icon to show a menu with available networks. The currently used connection is selected in the menu.

  2. To switch to another network, choose it from the list.

  3. To switch off all network connections, both wired and wireless, right-click the applet icon and uncheck Enable Networking.

27.5.2 Managing Wireless Network Connections

Available visible wireless networks are listed in the GNOME NetworkManager applet menu under Wireless Networks. The signal strength of each network is also shown in the menu. Encrypted wireless networks are marked with a shield icon.

Procedure 27.4: Connecting to a Wireless Network
  1. To connect to a wireless network, left-click the applet icon and choose an entry from the list of available wireless networks.

  2. If the network is encrypted, a dialog opens. It shows the type of encryption the network uses (Wireless Security) and holds a number of input fields according to the respective encryption and authentication settings. Enter the appropriate credentials.

  3. To connect to a network that does not broadcast its service set identifier (SSID or ESSID) and therefore cannot be detected automatically, left-click the NetworkManager icon and choose Connect to Hidden Wireless Network.

  4. In the dialog that opens, enter the SSID or ESSID in Network Name and set encryption parameters if necessary.

  5. To disable wireless networking, right-click the applet icon and uncheck Enable Wireless. This can be useful if you are on a plane or in any other environment where wireless networking is not allowed.

A wireless network that has been chosen explicitly will remain connected as long as possible. If a network cable is plugged in during that time, any connections that have been set to Stay connected when possible will be connected, while the wireless connection remains up.

27.5.3 Configuring Your Wireless Card as an Access Point

If your wireless card supports access point mode, you can use NetworkManager for configuration.

Note
Note: Availability of Options

Depending on your system setup, you may not be allowed to configure connections. In a secured environment, some options might be locked or require root permission. Ask your system administrator for details.

  1. Click the NetworkManager applet and select Create New Wireless Network.

  2. Enter a Network Name and set the encryption to use with the Wireless Security drop-down list.

    Important
    Important: Unprotected Wireless Networks Are a Security Risk

    If you set Wireless Security to 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. If you are not sure which technology is best for you, read Section 19.3, “Authentication”.

27.6 NetworkManager and VPN

NetworkManager supports several Virtual Private Network (VPN) technologies. For each technology, SUSE Linux Enterprise Server comes with a base package providing the generic support for NetworkManager. In addition to that, you also need to install the respective desktop-specific package for your applet.

NovellVPN

To use this VPN technology, install

  • NetworkManager-novellvpn and

  • NetworkManager-novellvpn-kde4 or NetworkManager-novellvpn-gnome.

NovellVPN support for KDE is not available yet, but is currently being worked on.

OpenVPN

To use this VPN technology, install

  • NetworkManager-openvpn and

  • NetworkManager-openvpn-kde4 or NetworkManager-openvpn-gnome.

vpnc (Cisco)

To use this VPN technology, install

  • NetworkManager-vpnc and

  • NetworkManager-vpnc-kde4 or NetworkManager-vpnc-gnome.

PPTP (Point-to-Point Tunneling Protocol)

To use this VPN technology, install

  • NetworkManager-pptp and

  • NetworkManager-pptp-kde4 or NetworkManager-pptp-gnome.

After you have installed the packages, configure your VPN connection as described in Section 27.3, “Configuring Network Connections”.

27.7 NetworkManager and Security

NetworkManager distinguishes two types of wireless connections, trusted and untrusted. A trusted connection is any network that you explicitly selected in the past. All others are untrusted. Trusted connections are identified by the name and MAC address of the access point. Using the MAC address ensures that you cannot use a different access point with the name of your trusted connection.

NetworkManager periodically scans for available wireless networks. If multiple trusted networks are found, the most recently used is automatically selected. NetworkManager waits for your selection in case that all networks are untrusted.

If the encryption setting changes but the name and MAC address remain the same, NetworkManager attempts to connect, but first you are asked to confirm the new encryption settings and provide any updates, such as a new key.

If you switch from using a wireless connection to offline mode, NetworkManager blanks the SSID or ESSID. This ensures that the card is disconnected.

27.7.1 User and System Connections

NetworkManager knows two types of connections: user and system connections. User connections are connections that become available to NetworkManager when the first user logs in. Any required credentials are asked from the user and when the user logs out, the connections are disconnected and removed from NetworkManager. Connections that are defined as system connection can be shared by all users and are made available right after NetworkManager is started—before any users log in. In case of system connections, all credentials must be provided at the time the connection is created. Such system connections can be used to automatically connect to networks that require authorization. For information how to configure user or system connections with NetworkManager, refer to Section 27.3, “Configuring Network Connections”.

For KDE, configuring system connections with NetworkManager are currently not supported (use YaST instead).

27.7.2 Storing Passwords and Credentials

If you do not want to re-enter your credentials each time you want to connect to an encrypted network, you can use the desktop-specific tools GNOME Keyring Manager or KWalletManager to store your credentials encrypted on the disk, secured by a master password.

NetworkManager can also retrieve its certificates for secure connections (for example, encrypted wired, wireless or VPN connections) from the certificate store. For more information, refer to Chapter 12, Certificate Store.

27.8 Frequently Asked Questions

In the following, find some frequently asked questions about configuring special network options with NetworkManager.

How to tie a connection to a specific device?

By default, connections in NetworkManager are device type-specific: they apply to all physical devices with the same type. If more than one physical device per connection type is available (for example, your machine is equipped with two ethernet cards), you can tie a connection to a certain device.

To do so in GNOME, first look up the MAC address of your device (use the Connection Information available from the applet, or use the output of command line tools like nm-tool or ifconfig). Then start the dialog for configuring network connections and choose the connection you want to modify. On the Wired or Wireless tab, enter the MAC Address of the device and confirm your changes.

If you are using KDE, start the dialog for configuring network connections and choose the connection you want to modify. On the Ethernet or Wireless tab, use the Restrict to Interface option to select the network interface to which to tie the connection.

How to specify a certain access point in case multiple access points with the same ESSID are detected?

When multiple access points with different wireless bands (a/b/g/n) are available, the access point with the strongest signal is automatically chosen by default. To override this, use the BSSID field when configuring wireless connections.

The Basic Service Set Identifier (BSSID) uniquely identifies each Basic Service Set. In an infrastructure Basic Service Set, the BSSID is the MAC address of the wireless access point. In an independent (ad-hoc) Basic Service Set, the BSSID is a locally administered MAC address generated from a 46-bit random number.

Start the dialog for configuring network connections as described in Section 27.3, “Configuring Network Connections”. Choose the wireless connection you want to modify and click Edit. On the Wireless tab, enter the BSSID.

How to share network connections to other computers?

The primary device (the device which is connected to the Internet) does not need any special configuration. However, you need to configure the device that is connected to the local hub or machine as follows:

  1. Start the dialog for configuring network connections as described in Section 27.3, “Configuring Network Connections”. Choose the connection you want to modify and click Edit. If you are using GNOME, switch to the IPv4 Settings tab and from the Method drop-down list, choose Shared to other computers. If you are using KDE, switch to the IP Address tab and from the Configure drop-down list, choose Shared. That will enable IP traffic forwarding and run a DHCP server on the device. Confirm your changes in NetworkManager.

  2. As the DCHP server uses port 67, make sure that it is not blocked by the firewall: On the machine sharing the connections, start YaST and select Security and Users › Firewall. Switch to the Allowed Services category. If DCHP Server is not already shown as Allowed Service, select DCHP Server from Services to Allow and click Add. Confirm your changes in YaST.

How to provide static DNS information with automatic (DHCP, PPP, VPN) addresses?

In case a DHCP server provides invalid DNS information (and/or routes), you can override it. Start the dialog for configuring network connections as described in Section 27.3, “Configuring Network Connections”. Choose the connection you want to modify and click Edit. If you are using GNOME, switch to the IPv4 Settings tab, and from the Method drop-down list, choose Automatic (DHCP) addresses only. If you are using KDE, switch to the IP Address tab, and from the Configure drop-down list, choose Automatic (DHCP) addresses only. Enter the DNS information in the DNS Servers and Search Domains fields. To Ignore automatically obtained routes click Routes (GNOME) and activate the respective check box, or from the drop-down list at the bottom of the tab (KDE), select Routes and activate the respective check box. Confirm your changes.

How to make NetworkManager connect to password protected networks before a user logs in?

Define a system connection that can be used for such purposes. For more information, refer to Section 27.7, “NetworkManager and Security”.

27.9 Troubleshooting

Connection problems can occur. Some common problems related to NetworkManager include the applet not starting or a missing VPN option. Methods for resolving and preventing these problems depend on the tool used.

NetworkManager Desktop Applet Does Not Start

The GNOME and KDE NetworkManager applets start automatically if the network is set up for NetworkManager control. If the applet does not start, check if NetworkManager is enabled in YaST as described in Section 27.2, “Enabling or Disabling NetworkManager”. Then make sure that the appropriate package for your desktop environment is also installed. If you are using KDE 4, the package is NetworkManager-kde4. For GNOME users the package is NetworkManager-gnome.

If the desktop applet is installed but is not running for some reason, start it manually. If the desktop applet is installed but is not running for some reason, start it manually with the command nm-applet (GNOME) or knetworkmanager (KDE).

NetworkManager Applet Does Not Include the VPN Option

Support for NetworkManager, applets, and VPN for NetworkManager is distributed in separate packages. If your NetworkManager applet does not include the VPN option, check if the packages with NetworkManager support for your VPN technology are installed. For more information, see Section 27.6, “NetworkManager and VPN”.

No Network Connection Available

If you have configured your network connection correctly and all other components for the network connection (router, etc.) are also up and running, it sometimes helps to restart the network interfaces on your computer. To do so, log in to a command line as root and run rcnetwork restart.

27.10 For More Information

More information about NetworkManager can be found on the following Web sites and directories:

NetworkManager Project Page

http://projects.gnome.org/NetworkManager/

KDE NetworkManager Front-End

http://userbase.kde.org/NetworkManagement

Package Documentation

Also check out the information in the following directories for the latest information about NetworkManager and the GNOME and KDE NetworkManager applets:

  • /usr/share/doc/packages/NetworkManager/,

  • /usr/share/doc/packages/NetworkManager-kde4/, and

  • /usr/share/doc/packages/NetworkManager-gnome/.

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