auto eth0
iface eth0 inet static
   address 192.168.1.57
   netmask 255.255.255.0
   gateway 192.168.1.1
   up ip addr add 192.168.0.57/24 dev eth0 label eth0:1
   down ip addr del 192.168.0.57/24 dev eth0 label eth0:1
   up ip route add 192.168.0.0/24 via 192.168.0.1 dev eth0:1 metric 20
   down ip route del 192.168.0.0/24 via 192.168.0.1 dev eth0:1 metric 20