3.2.1.1.3. Saving and using the network configuration
To save the network configuration that you have configured using the GUI tool, select the menu option File->Save. This will update the network configuration files with your changes but will not immediately activate those changes.
To enable or disable network interfaces, go to the Devices tab ( Figure 3-6 ), select the interface you wish to change, and click Activate or Deactivate. Alternately, you can exit from the network configuration tool and restart the Network service graphically (see Lab 4.6, "Managing and Configuring Services ") or by entering this command:
# service network restart
Shutting down interface eth0: [ OK ]
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: [ OK ]
Network interface devices which are set to activate at boot will automatically start up when the network interface is started. Other devices may be started and stopped using the network configuration tool.
However, if the option labeled "Allow all users to enable and disable the device" has been set in the interface device configuration ( Figure 3-12 ), any user can activate or deactivate the device using the GNOME menu option Application->System Tools->Network Device Control (in KDE, System->Network Device Control).
This option may not appear on your GNOME menu; to make it available, right-click on the GNOME application menu and select Edit Menus. Figure 3-17 shows the menu editor that appears.
Figure 3-17. The GNOME menu editor
Select Applications->System Tools in the left pane, select the checkbox labeled Network Device Control in the right pane, and then click on the Close button.
When you start the Network Device Control program, either through the menu or by typing system-control-network in a shell, the window shown in Figure 3-18 will appear.
Figure 3-18. Network Device Control window
To activate or deactivate network interface devices using this program, select the interface and click on the Activate or Deactivate buttons. Click Close when you are done with the window.
You can also activate and deactivate network interfaces from the command line using the ifup and ifdown commands:
# ifconfig eth1
eth1 Link encap:Ethernet HWaddr 00:0C:2D:00:2B:DB
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:794 errors:0 dropped:0 overruns:0 frame:0
TX packets:195 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:115671 (112.9 KiB) TX bytes:19491 (19.0 KiB)
# ifup eth1
Determining IP information for eth1... done.
# ifconfig eth1
eth1 Link encap:Ethernet HWaddr 00:0C:2D:00:2B:DB
inet addr:172.16.97.101 Bcast:172.16.97.255 Mask:255.255.255.0
inet6 addr: fe80::20c:2dff:fe00:2bdb/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:802 errors:0 dropped:0 overruns:0 frame:0
TX packets:213 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:117520 (114.7 KiB) TX bytes:22579 (22.0 KiB)
# ifdown eth1
# ifconfig eth1
eth1 Link encap:Ethernet HWaddr 00:0C:2D:00:2B:DB
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:802 errors:0 dropped:0 overruns:0 frame:0
TX packets:213 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:117520 (114.7 KiB) TX bytes:22579 (22.0 KiB)