In RHEL/CentOS or Fedora, you can configure network interfaces by using configuration files located in /etc/sysconfig/network-scripts/. For each network interface (e.g., eth0), there should be a corresponding configuration file (e.g., ifcfg-eth0) in the directory. If you would like to configure a network interface, do the following.
$ sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0
If you would like to assign a static IP address to the interface:
DEVICE=eth0 BOOTPROTO=static HWADDR=00:05:29:E0:4F:3D IPADDR=10.0.1.10 NETMASK=255.255.255.0 GATEWAY=10.0.1.1 ONBOOT=yes TYPE=Ethernet
If the interface has IP address assigned by DHCP:
DEVICE=eth0 BOOTPROTO=dhcp HWADDR=00:05:29:E0:4F:3D ONBOOT=yes TYPE=Ethernet
Once network configuration has been created/updated, you can activate a network interface by running:
$ sudo service network restart
Note that if you are using Desktop version of Linux, you will need to disable NetworkManager first, before attempting to configure interfaces as described above.