auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 200.0.0.1
    netmask 255.255.255.0

auto eth1
iface eth1 inet static
    address 201.0.0.1
    netmask 255.255.255.0
    up ip route add 202.0.0.0/24 via 201.0.0.2
    up ip route add 203.0.0.0/24 via 201.0.0.2
