The forwarding ports are not functioning properly.
The forwarding ports are not functioning properly.
Keep in mind a port will only report as being open when there's actually something listening on that port for connections. If you enable remote desktop, that computer starts listening on port 3389 TCP. If you forward that port and check if it's open, it'll report as open. If you don't have anything listening on port 2456, but still forward that port, it will report as closed.