Chapter 10. NetworkManager
NetworkManager is a dynamic network control and configuration system that attempts to keep network devices and connections up and active when they are available. NetworkManager consists of a core daemon, a GNOME Notification Area applet that provides network status information, and graphical configuration tools that can create, edit and remove connections and interfaces. NetworkManager can be used to configure the following types of connections: Ethernet, wireless, mobile broadband (such as cellular 3G), and
PPPoE(Point-to-Point over Ethernet). In addition, NetworkManager allows for the configuration of network aliases, static routes, DNS information and VPN connections, as well as many connection-specific parameters. Finally, NetworkManager provides a rich API via D-Bus which allows applications to query and control network configuration and state.
Previous versions of Red Hat Enterprise Linux included the Network Administration Tool, which was commonly known as
system-config-networkafter its command-line invocation. In Red Hat Enterprise Linux 6, NetworkManager replaces the former Network Administration Tool while providing enhanced functionality, such as user-specific and mobile broadband configuration. It is also possible to configure the network in Red Hat Enterprise Linux 6 by editing interface configuration files; see Chapter 11, Network Interfaces for more information.
NetworkManager may be installed by default on your version of Red Hat Enterprise Linux. To ensure that it is, run the following command as
yum install NetworkManager
10.1. The NetworkManager Daemon
The NetworkManager daemon runs with
rootprivileges and is usually configured to start up at boot time. You can determine whether the NetworkManager daemon is running by entering this command as
service NetworkManager statusNetworkManager (pid 1527) is running...
servicecommand will report
NetworkManager is stoppedif the NetworkManager service is not running. To start it for the current session:
service NetworkManager start
chkconfigcommand to ensure that NetworkManager starts up every time the system boots:
chkconfig NetworkManager on
For more information on starting, stopping and managing services and runlevels, see Chapter 12, Services and Daemons.