@HeMaN this may have actually worked...
In etc/network/interfaces
The primary network interface
allow-hotplug eth0
iface eth0 inet dhcp
This is an autoconfigured IPv6 interface
iface eth0 inet6 auto
post-up route add default via 10.10.10.1 dev eth0
auto eth1
iface eth1 inet static
address 10.10.5.188
post-up route del default dev eth1