1. Interface configuration using DHCP service example:

   #vim /etc/sysconfig/network-scripts/ifcfg-eth0
   DEVICE=eth0
   BOOTPROTO=dhcp
   HWADDR= 00-19-DB-AD-19-99
   ONBOOT=yes

2. Interface configuration using manually set parameters:

   #vim /etc/sysconfig/network-scripts/ifcfg-eth0
   DEVICE=eth0
   HWADDR= 00-19-DB-AD-19-99
   IPADDR=192.168.1.2
   NETMASK=255.255.255.0
   BROADCAST=192.168.1.255
   GATEWAY=192.168.1.1
   ONBOOT=yes
   DNS1=8.8.8.8
   DNS2=8.8.4.4

To check the interface configuration:

  ifconfig eth0

To check the routes:

  netstat -r

To restart the interface and to apply the new settings:

  ifdown eth0 - disable
  ifup eth0 - enable