How to add multiple IP addresses manually

# ifconfig

will output all the configured addresses

eth0: inet addr:10.8.0.10 Bcast:10.8.0.255 Mask:255.255.255.0

To add on extra IP addresses execute below command:

# ifconfig eth0:1 10.8.0.12 netmask 255.255.255.0

For additional IP addresses, make sure you increment the 1 in eth0:1

Third ip address would be like this

# ifconfig eth0:2 10.8.0.13 netmask 255.255.255.0