CentOS includes a graphical interface to configure networks on your computer. You can also configure networks through the command line. With the default CentOS tool, you can manage your Ethernet and wireless connections. Advanced settings include managing hosts and DNS configuration. CentOS allows you to save and restore your network configuration as well.
Opening the Network Administration Tool
The Network Administration Tool in CentOS is located in the System Settings menu, which you can access from your desktop by clicking "Applications." Click "Network" to open the Network Administration Tool. The default screen shows you a list of your network devices and whether they are currently active or not. To open the Network Administration Tool from the command line, type "system-config-network." If you use Xterm, the GUI interface will open. However if you use a GNOME terminal, you will need to use terminal commands to configure a network.
Establishing a Connection
To start a network connection, click "New" while in the Devices tab. You will see a list of possible device types, such as Ethernet, Wireless, Modem and ISDN. Select the device type you want, and click "Forward." You should see a list of the devices that can establish the connection on your computer. Select the one you want. If you do not see your device listed, click "Other" and add your device. The Network Configuration menu will pop up. Your options depend on the type of connection. When you have the options you want, click "Forward." Select "Save" in the File menu to save the connection.
In the DNS tab of the Network Administration Tool, you can set the DNS records for a system, including the host name, name servers and search path. The Host tab allows you to add hosts to the network. At the command line you can save your network configuration to a file on your computer and restore the configuration from the file. Type "system-config-network-cmd -e > /path/filename" to save the settings. To restore them, type "system-config-network-cmd -i -c -f /path/filename." Both commands must be run as the root user.
If you are new to Linux, you should not use the command line to configure your network other than to save and restore. However, you can see a list of available terminal commands by typing "system-config-network-cmd --help." If you are having problems with your network, search for help online for the particular problematic device. Different wireless cards require different procedures to troubleshoot, for example, so always look for the hardware that you have installed on your computer.