Question Portforward

Jul 2, 2022
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I just wanted to open port for valheim but suddenly All my ports are closed it worked for a month ago
 
Pretty much the standard 3 things you check.

First be sure you are using the correct public IP. Also verify that the IP you see on the wan interface as your router is the same as you see on a site like whatsmyip. If these are different you do not have a public IP.
Check the server actually has a process open on the port. You should be able to see it in the resource monitor network tab. You also if you can connect to the server from the lan using the local lan IP.
Many times the port forwarding rules are strange try DMZ instead since it is easier to get setup.

After that you need to determine how far the traffic is getting. I would start by loading wireshark on the server and see if you see anything when you scan the ports.
 
Jul 2, 2022
3
0
10
Pretty much the standard 3 things you check.

First be sure you are using the correct public IP. Also verify that the IP you see on the wan interface as your router is the same as you see on a site like whatsmyip. If these are different you do not have a public IP.
Check the server actually has a process open on the port. You should be able to see it in the resource monitor network tab. You also if you can connect to the server from the lan using the local lan IP.
Many times the port forwarding rules are strange try DMZ instead since it is easier to get setup.

After that you need to determine how far the traffic is getting. I would start by loading wireshark on the server and see if you see anything when you scan the ports.

I can join the game in lan and ip are the same and DMZ dosent Work either i Will try to download wireshark and see how far it goes
 
It can be confusing if you are using the machine for other stuff and then run wireshark. There can be massive amounts of data and for someone who is not going to use it a lot it does not pay to learn how to build a filter.

Generally the easiest thing to see is going to be to set the router to DMZ mode so lots of ports are allowed. Then on some port scanner site scan a large range of ports. That will generate quite a bit of traffic which you are more likely to see just scrolling around in the capture.
Best would be to have the machine running wireshark doing nothing at all. Close all web pages etc. I would even close your game the very first time you do the wireshark. Then from a completely different device tell the remote web site to scan you. This way you are not captuing all the traffic that basically is you clicking on some boxes. Even a simple web page generate many packets of data.

What you should see are a bunch of incoming SYN packets from some IP on the internet. You should see it try a number of different ports.

Now nothing will work and the scanner will say all ports are closed but what you know is the traffic got all the way to your machine. If it does not then need to look at maybe the router setting or plug your PC directly into the modem if that is a option and test the scanner again.

If you get data into the port the game uses you can turn the game on and verify that it responds. It should send a syn-ack packet back as the first and likely more. If it does not there is something wrong with the application or maybe a firewall or something else in the server.