After you have installed CentOS 6.2 linux server, the network configuration will be like this.
DEVICE="eth0"
HWADDR="xx:xx:xx:xx:xx:xx"
NM_CONTROLLED="yes"
ONBOOT="no"
The system will no get the ip automatically and the network interface will not auto start even after the server rebooted. Follow this steps to set static ip and set it auto start once rebooted in CentOS 6.2 :
1. Configure eth0:
[root@centos6 ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE="eth0"
HWADDR="00:0C:29:67:51:B1"
NM_CONTROLLED="yes"
ONBOOT="yes"
IPADDR=192.168.1.44
BOOTPRO=static
NETMASK=255.255.255.0
2. Configure Default gateway:
[root@centos6 ~]# vi /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=centos6.2
GATEWAY=192.168.1.1
3. Restart Network interface:
[root@centos6 ~]# /etc/init.d/network restart
or
[root@centos6 ~]# Service network restart
4. Configure DNS server:
[root@centos6 ~]# vi /etc/resolv.conf
nameserver 8.8.8.8
nameserver 192.168.1.1