HowTo : Change Speed and Duplex of Ethernet card in Linux

To change Speed and Duplex of an ethernet card, we can use ethtool - a Linux utility for Displaying or Changing ethernet card settings.

Configuring Network on CentOS/RHEL -- Basic Configuration

Interface configuration files control the software interfaces for individual network devices.

As the system boots, it uses these files to determine what interfaces to bring up and how to configure them.

These files are usually named ifcfg-<name>, where <name> refers to the name of the device that the configuration file controls.

Because each device has its own configuration file, an administrator can control how each interface functions individually.