Disabling Network Manager

1. Verify Network Manager is currently enabled using the chkconfig command.

   # chkconfig --list NetworkManager

   The output displayed by the chkconfig command inicates 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.
2. Ensure that the Network Manager service is stopped using the service command.

   # service NetworkManager stop

3. Ensure that the Network Manager service is disabled using the chkconfig command.

   # chkconfig NetworkManager off

4. 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.
5. Ensure that the network service is started using the service command.

   # service network start

6. 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.