Is if there is nothing that responds to a UDP or TCP request, then does it matter?
Also, your router drops all unsolicited inbound connection requests (default) so is that closed too?
As to your remote desktop, you test by actually trying it.
I Recentely implemented Portforwarding and it is working fine.
<Public IP address>:23223 forwarded to <Internal IP>:3389. which is using for a remote desktop for a temperary period of time.
I just want to find out that port is opened or not?
I tried commands
nmap <ipaddress> - not showing that port is opened
Can anyone help me to list the ports opened on the Public IP?