Sat May 14, 2022 6:24 pm
@rextended: I believe that OP wants something that can actually be useful. Current UPnP adds dstnat rules with in-interface=<external interface>. If it was possible to choose address list as external interface, it could add rules with in-interface-list=<list of external interfaces>, which would make port forwarding work from all. So at least at first sight it could make sense.
One problem I see is that client can also get external address from UPnP, and I don't know if there's any support for multiple addresses. If not, it hurts the usefulness. If UPnP client opens port, gets external address and sends it to remote party, so that it can connect to it, and it will be just one address, then possibility to have incoming connections using other WANs doesn't help anything.