nano /etc/network/interface

allow-hotplug eth0
iface eth0 inet static
    address 192.168.1.1
    netmask 255.255.255.0
    gateway 192.168.1.254

nano /etc/network/interface

allow-hotplug eth0
auto eth0
iface eth0 inet dhcp

auto eth0:0
iface eth0:0 inet static
    address 192.168.1.2
    netmask 255.255.255.0

auto eth0:1
iface eth0:1 inet static
    address 192.168.1.3
    netmask 255.255.255.0