Virtual IP addresses
You can add several virtual IP addresses to a physical network interface. A good starting point is to copy the interface definition file of the device you want to add a virtual IP address to.
cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0:0
You may have to modify ifcfg-eth0 to match your physical interface name.
Now you can edit the new file ifcfg-eth0:0 and specify the network settings of the virtual interface.
If you want the virtual IP address come up on boot, you need to remove
and make it
This makes the interface only come up when the parent interface comes up, while ONBOOT=YES would pull up the parent interface even if that is configured to not come up on boot.
To make the changes take effect please restart the network services using:
service network restart