you need to first install NetworkManager using YUM
yum install NetworkManager
Or check it is already started or not
service NetworkManager status
else start the service
service NetworkManager start chkconfig NetworkManager on
To open to GUI interface you need to execute “nm-applet” command. and to configure or edit configurations “nm-connection-editor” use this command
nm-applet nm-connection-editor (note: this command is formerly known as system-config-network-gui)
