Bind to secondary gateway

[Azureit]

I have two network cards serving my computer with two gateways.
ip route show
default via 10.0.0.1 dev eth0 proto static metric 100
default via 192.168.0.1 dev eth1 proto static metric 600
10.0.0.0/24 dev eth0 proto kernel scope link src 10.0.0.2 metric 100
192.168.0.0/24 dev eth1 proto kernel scope link src 192.168.0.2 metric 600

I want to use the secondary gateway, eth1, to connect to ShadowVPN server.
I modify the ShadowVPN code to bind the socket to eth1 like this:
setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, "eth1", 4);
This is not working, but the UDP packets are send correctly via eth1 and the ShadowVPN server responds correctly, because I monitor the incoming packets with wireshark at eth1, but the ShadowVPN client will not capture those packets from server.

Thanks for any help.

[hieixu]

You can do this via route command.
route add -host vpn_server_ip gw 192.168.0.1