It is possible to bind more than one ip address on a single network interface card in linux.

copy your existing network card  configuration file as shown:

#cd /etc/sysconfig/network-scripts
#cp ifcfg-eth0 ifcfg-eth0:1

>>ifcfg-eth0 looks like this :

# File: ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.100.1
NETMASK=255.255.255.0
BROADCAST=192.168.100.255
NETWORK=192.168.100.0
HWADDR=00:8A:4E:34:CF:84

Change the device name and the ip address parameters

File : ifcfg-eth0:1
and
DEVICE=eth0:1

#save the fiel and then restart the network

#service network restart