The Network Manager service is currently enabled by default on Red Hat Enterprise Linux installations where one of these package groups was selected during installation:
Desktop
NM_CONTROLLED will be installed so that your network interface be managed the NetworkManager daemon. This means the traditional means of managing your network interfaces via the /etc/sysconfig/network-scripts/ifcfg-ethX files will no longer work. Thus, our problem.
Network Manager should be disabled and replaced by the standard network service for all interfaces. To disable NetworkManager do the following steps:
Verify Network Manager is currently enabled using the chkconfig command.
# chkconfig –list NetworkManager
The output displayed by the chkconfig command indicates whether or not the Network Manager service is enabled.
The system displays an error if the Network Manager service is not currently installed:
error reading information on service NetworkManager: No such file or directory
If this error is displayed then no further action is required to disable the Network Manager service.
The system displays a list of numerical run levels along with a value of on or off indicating whether the Network Manager service is enabled when the system is operating in the given run level.
NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off
If the value displayed for all run levels is off then the Network Manager service is disabled and no further action is required. If the value displayed for any of the run levels is on then the Network Manager service is enabled and further action is required.
Ensure that the Network Manager service is stopped using the service command.
# service NetworkManager stop
Ensure that the Network Manager service is disabled using the chkconfig command.
# chkconfig NetworkManager off
Open each interface configuration file on the system in a text editor. Interface configuration files are found in the /etc/sysconfig/network-scripts/ directory and have names of the form ifcfg-X where X is replaced by the name of the interface. Valid interface names include eth0, p1p5, and em1.
In each file ensure that the NM_CONTROLLED configuration key is set to no and the ON_BOOT configuration key is set to yes.
NM_CONTROLLED=no
ONBOOT=yes
This action ensures that the standard network service will take control of the interfaces and automatically activate them on boot.
Ensure that the network service is started using the service command.
# service network start
Ensure that the network service is enabled using the chkconfig command.
# chkconfig network on
The Network Manager service has been disabled. The standard network service has been enabled and configured to control the required network interfaces.
Reference Document
