To add the additionaly static IP to Ubuntu server follow the steps

1) vi /etc/network/interfaces, here you will see the already configured IP


auto eth0
iface eth0 inet static
address 192.168.0.10
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 109.203.116.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.0.254
dns-search mynetwork.com

2) Copy above lines and paste under these after doing following changes.

auto eth0:1 # change eth0 to eth0:1
iface eth0:1 inet static # change eth0 to eth0:1
address 192.168.0.11 # mention another IP and rest of the lines will be same
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 109.203.116.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.0.254
dns-search mynetwork.com

3) Once it is pasted, then save the file and quite

4) restart networking service

#/etc/init.d/networking restart

5) verify the settings with command

#ifconfig