allow-hotplug usb0
auto usb0
iface usb0 inet static
        address 192.168.2.14
        netmask 255.255.255.0
        up iptables -A POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
        up echo 1 > /proc/sys/net/ipv4/ip_forward
        down iptables -D POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
        down echo 0 > /proc/sys/net/ipv4/ip_forward