Question Port Checker is saying all my ports are closed but I have had people connect to me.

[Rizzano1974]

I run a server for a game called 7 Days to Die. The default port is 26900. Port checker says this port is closed even though A) I have it open on Windows Defender Firewall, B) I have it open on AVG Firewall, and C) I have it forwarded on my router. People can join my server just fine, and I even had a discord link from a server mod that displayed the game server chat in the configured discord channel. This is not odd. The other thing is, I am trying to host another server, SCUM server, and that port is 7779. Again, I have it forwarded and opened on all fronts, but port checker is saying it is closed. The port checker also says HTTP port is closed, the mail port 110 is closed, FTP 21 is closed, and every port I try says it's closed. I do have a VPN installed but it is not paid for and not having an active subscription so I do not have it even running. I always shut it off when my computer reboots. I should also note that I disabled all my security stuff temporarily to see if that would make a difference and it does not. Port checker is STILL saying my ports are ALL closed. I should also say my connection is wired and I have a 500MBPS connection.

DO:

• Provide us with the make and model of your laptop (if applicable) - GIGABYTE G6KF (RC56KF is the SKU)
• Provide us with the make and model of your router - Starry Gravity version 2022.10.05.1
• Provide us with the exact specifications of your PC (if applicable) including: - Intel 13th Gen Core i7 i3620H 2400 MHZ 10 Cores, 16 Logical Processor, 32GB Ram, RTX 4060

- Make and model of motherboard - 6-77-NP60RND2Y0-D02 GIGABYTE G6 KF

• 
  
  • Make and model of power supply - 150W Power Supply 54WHr battery
  • Make and model of USB or PCI Wifi adapter - Realtek PCIe GbE Family Controller
  • Operating system and driver version - Windows 11 - 10.0.26.100 Build 26100

• You will also need to post your ISP and connection type*. - Starry, supports both wireless and wired, 500MBPS connection.
• You will also need to post the exact number of devices connected to your router (this includes tablets, smart phones, laptops, and desktop PCs) as some routers can only handle a specific number of devices at a time. - I have 9 devices but not all are using the connection at the same time, and like I stated above, I ran a 7 Days to Die game server and people connected to it, downloaded the world files from me, and played just fine, no hiccups.
• Post any and all error messages you are getting from your ISP or Windows itself -

[ Moderator edit: link showin public IP address removed.]

• My starry app reports my connection is 489MBPS, speedtest actually whoed 528MBPS. I have had no internet issues accessing anything at all.

WIRED LAN CONNECTION ONLY

If you are operating on a wired connection as opposed to wireless these items will also need to be provided:

• Make and model of switches and how many ports are on each switch- I do not know this information. I know it's capable of GB;s of speed, I think it was 10GB.
• How many PCs and laptops are connected to the network - 2 Laptops, 1 PC.
• Whether or not a NAS (Network Attached Storage) or regular server is connected to the network - No
• Whether or not a Wifi router is connected to the network and/or switch - Yes, Starry Gravity
• If you are using the internal LAN connection on your motherboard, a USB dongle, or external PCI card - Internal LAN, hardwired from the wireless capable router, with a CAT6 cable I believe. I upgraded my cable to make sure I could host the 7 days to die server,

I can also provide screenshot of the ports that I have forwarded, and I have tested all of these ports.

THINGS I HAVE TRIED: Restarting the router after the port forward change, restarting my laptop after the change. Restarting the server.exe after the change. Testing the ports again on the 7 Days to Die server and again friends are able to connect. Testing the ports on portchecker.io and they all say closed.

 

[evermorex76]

You should never post your public IP address to the forums or any other site as it can be used in an attack. The mods will probably redact that image.

So, the actual problem you want help with is the SCUM server, right? The 7D2D port is just an additional indication?

The test site will only be able to connect to the port successfully when the service is actually running on your computer, so the first question is whether you have SCUM and 7D2D running when you tested.

Next is to look at whether Windows actually shows that it's listening on those ports. Open a command prompt and run "netstat -na", then copy all that text to a notepad window and search for 26900. You should see something like these:
TCP 192.168.1.101:26900 0.0.0.0:0 LISTENING
TCP 127.0.0.1:26900 0.0.0.0:0 LISTENING
TCP 0.0.0.0:26900 0.0.0.0:0 LISTENING

It may be listed a few times. The most important is either your computer's actual IP or 0.0.0.0 (which means all interfaces). Do the same search with the SCUM server port 7779. (I found several different lists of the ports used by SCUM, so I assume you verified that is the only one you need. If you haven't got all the right ports open then that would also affect)

Then you can test whether connections can be made, again via command line. On your own machine, run "telnet 127.0.0.1 26900" to test 7D2D's port. It should briefly say Connecting and then either just go to a blank line or perhaps it will give some text, or if you press enter a few times it will respond with something, or it will disconnect with a message. But as long as it doesn't say that it failed, then it worked. If it says "could not open connection to the host" (which takes about 30 seconds) then the Windows firewall or some other firewall software is blocking it, even though the service is listening. Then do the same thing with your actual computer local IP instead of 127.0.0.1. Then go to another wired computer on the network and do the same test. Presumably all of this will work since you say 7D2D works okay. Then try it all again using the SCUM port.

If those all work, then you know for sure your computer is set up to allow everything and can address whether the firewall is forwarding it. If you have access to a machine somewhere else, you could run the same telnet tests from there, but that's basically what the test sites are doing. You may be able to log into your router and monitor the logs to see if they show whether the incoming connection is being forwarded or blocked at the moment of the connection attempt.

 

[Ralston18]

Link with Public IP address removed.

OP: you can repost the image - just be sure to redact or mask out the Public IP address.

 

[bill001g]

There are three things that must function for port checker to work correctly.

1. You must have a public IP and of course be testing the proper IP.
2. Your must have the proper port forwarding rules set up.
3. There must be a program actually listening on this port and respond correctly.

#3 tends to be the place of most confusion. The obvious one would be if you turn your machine off it will not respond but this is also true if you are not running a program that is designed to respond on that port. Some programs are smart/secure and will only respond on certain ports to certain remote IP that have been in some way validated. This varies a lot between applications.

The easy first test is to use the DMZ option in the router to forward all ports. This is not a good long term setting but it will quickly tell you if it is some problem with the port forwarding rules. Many routers are extremely confusing setting up port forwarding.

So if DMZ still shows nothing the next step is to see if you are actually receiving any traffic. Load wireshark or another capture software. I would only have the single browser tab open to the testing site. It will still be a lot of data capture so you want to minimize how much you need to look through. You should see traffic coming in from the testing server to the ports you asked it to test.

You goal is to see if you actually see those packets recieved by your machine. This would mean #1 and #2 from above are correct. You now must determine if your machine actually responds and somehow the response is lost or the machine is ignoring the test data for some reason.

Wireshark captures before the firewall but you said it is allowed. You could also for a very short period disable the firewall.