Could you please tell a bit more about your setup how exactly you have configured everything (without too personal information of course ;) )? As you mention xDSL, I assume you are using PPPoE? If this is the case, please consider that the IPs/subnets you configured is only to access the management interface. PPPoE (as the name already says) works on Ethernet level (not IP level) and I'm not sure if this works over the same physical interface (not only in theory but also with real equipment), have never seen that.