The Port remains open following portforwarding.
The Port remains open following portforwarding.
All my attempts have failed so far. I've used the DMZ, updated firmware, restarted the router, etc. Before sharing, yes, I'm running the server, firewall is off, I'm testing the port with my public IP, I'm forwarding local IPv4, and my router isn't NAT or CG-NAT—since I've done that before on an old PC; it's not working now. Any advice?
Do you have another PC available for testing the connection through the local LAN? (Or a mobile app on a phone/tablet can be used.) We should start from scratch to check if the problem lies with the PC or the port forwarding. Also, run "netstat -na" in the command prompt and find the lines with the correct port number to confirm it's actually listening. Is it TCP or UDP? Does Windows networking indicate that the interface is Public or Private? Why would you turn off the Windows firewall instead of just adding a rule for the right port?
Even though you claim your router isn't behind a NAT/CGNAT, this remains the most frequent reason for the issue. I recommend verifying once more, as most devices display the real IP assigned to the wan interface—confirm it matches the public IP you're testing.
Next, I suggest revisiting the DMZ setting. After launching wire shark on your machine, you can apply advanced filters but it's better to let it capture everything and manually review the logs. Direct a scan from one of the scanning sites asking it to probe a range of ports. Since DMZ should forward all traffic, expect those entries to appear as closed.
The aim here isn't just to check if ports respond, but whether the data actually reaches your machine. Scanning multiple ports simplifies identification in the capture.
Wireshark seems to still intercept data before the firewall or other filtering tools are applied.
At this stage, you should determine whether the problem lies with the router itself, external interference, or if the PC is receiving the data but failing to respond. It may also help testing directly on the port where the data arrives—if it reaches the PC but doesn't return a response along the way.