ifup configuration not found

Sometimes, if you use "ifup eth0" , but get following error:
/sbin/ifup:configuration for etho not found usage :ifup

Then you need to create a config file like:
/etc/sysconfig/network-scripe/ifcfg-eth0

Here is the sample content for CentOS 5:
DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=XX:XX:XX:XX:XX
ONBOOT=no