@Lynwood
The interface name option is valid ONLY for point to point interfaces, like PPTP or PPoE, where it should support a dynamic IP, and does not support interfaces which allow more than one peer IPs like ethernet. Even if it will create the routes for a ethernet interface, it will not work since it expects that specific IP for which it is created to be physically connected to that interface (which is not the case).
@Gustavo
That traffic reduction/increase is not a relevant indicator since except re-sending the RIP packages on the defined interface there is nothing the daemon does. Except adding the interface handling, nothing is changed from the test version I sent to you.
Marius, YO2LOJ