add virtaul IP on Ubuntu

#sudo vim /etc/network/interfaces

auto lo
iface lo inet loopback

Add script virtual ip :

auto eth0
iface eth0 inet static
address 192.9.18.27
netmask 255.255.255.0
gateway 192.9.8.8
dns-nameservers 180.131.144.144

auto eth0:0
iface eth0:0 inet static
address 192.168.1.12
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 180.131.144.144