Hello, I've got two DSL lines on a MT in load-balancing thus any connection can be sent through gateway 10.1.1.2 or by 10.1.1.3.
Requests for VPN connections are received through 10.1.1.2 so I want that any VPN reply goes through 10.1.1.2 and not through 10.1.1.3, if not the VPN can't be established.
I tried marking packets on output chain with protocol GRE and they are routed through gw 10.1.1.2 but it sometimes doesn't work. Do you know if there are other ways to make this work?

Thanks
Sergio