configuration of network
Configure network interface in Centos
make sure your OS detected network card
# dmesg |grep eth
eth0: RealTek RTL8139 at 0xf8cee000, 50:67:f0:5e:ac:2f, IRQ 21
edit network configuration file for eth0
# vim /etc/sysconfig/network-scripts/ifcfg-eth0
# Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+
DEVICE=eth0
BOOTPROTO=static
HWADDR=50:67:F0:5E:AC:2F
ONBOOT=yes
IPADDR=192.168.0.1
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
NETMASK=255.255.255.0
restart network service
# service network restart
or
# /etc/init.d/network restart