Run dhcp when system starts up on Cent OS

configure /etc/sysconfig/network-script/ifcfg-eth4

DEVICE=eth4

HWADDR=00:26:B9:38:4C:23

TYPE=Ethernet

ONBOOT=yes

NM_CONTROLLED=yes

BOOTPROTO=dhcp

if you set the onboot=yes, the system will run dhcp when system boots