If you have purchased a second ip address for your Centos installation and need to add the new static ip address, follow these simple steps:
Create the following file:
/etc/sysconfig/network-scripts/ifcfg-eth0:1
And inside this file add the following contents, be sure to replace 123.45.67.89 with your new ip address:
DEVICE=eth0:1
BOOTPROTO=static
IPADDR=123.45.67.89
NETMASK=255.255.255.0
ONBOOT=yes
Once completed, activate this and restart networking with the following commands:
# ifup eth0:1
# service network restart
If you need further assistance please open a ticket with the support department and we may assist you.