AR-750S-ext which ports are in use


can somebody tell me which ports are in use by the router itself.
I need to forward VPN ports to my qnap server.

Thank you very much

The router uses
53, 80, 83, 443, etc.

So do not uses these port.

Seems qnap server is using 8080 by default. 8080 free to use.

Thank you for your quick reply. I connected an old DDWRT router between my modem and lan and let qnap open the ports by upnp. The ports Qnap opened are:
TCP 80,443,8080,8081,1723 and
UDP 500,1194,1701,4500

When forwarding above ports on my old DDWRT router, I can access my Qnap server with my portable Android phone.

When forwarding the same ports on AR-750S, I can not access my server.

What could be the problem?

thank you

try this command to see ports in use

Hello, thank you for your response.
I did, and the only common ports are 80 and 443. I changed port 80 to 85 and removed 443. Here is a picture of my forward rules

sorry I don’t know anything about qnap and not sure about your entire setup. if you can’t get up and running you may have to find a good friend to take a hands on look at it as there may be more info to the setup. sorry.

Maybe you can do a dmz and forward all the ports?

I had to reset my router. Forwarded the ports again and then it worked.