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can't get to the prtg core using external IP address




Since my last question, something ... weird ... happened to my computer, requiring me to reload the prtg program.

When it was loaded it gave me a message "Please wait for prtg server to start". Reading through other threads, I went to make sure that the port I had was 80. In PRTG Administration, it showed the port as 8080. So I changed it to 80. The program stopped and started the services, and after re-opening the PRTG admin Program, the port was still 8080. I have run the program as Administrator in Windows to make sure it wasn't a privileges thing. The same happened.

So I tried opening my web browser (Brave) and entered the external IP for my machine to port 8080 i.e. http://<the ip address>:8080 and I get a request timeout.

In the PRTG administration tool, I figured I had to add the external ip address for my computer in the Core Tab, but it doesn't let me do this. I see the loopback and internal addresses and they are checked off.

Anyone have any ideas?


installation timeout web-interface

Created on Dec 13, 2017 2:47:44 PM

2 Replies




1. What are you trying to achieve?
1a. Base on your question is sounds like you are trying to the core PRTG to the internet over HTTP, is that correct?
2. Are you using a firewall to expose the PRTG computer to the internet?

I'll assume yes to 1a, if so I would challenge you to stop and instead use HTTPS (standard port is TCP 443) to protect yourself from clear text data transmission to and from core server over the internet.

Now in regards to your question Anyone have any ideas, with the information you have provided it sounds like another application is running on the computer that is using TCP port 80. To check this please stop the PRTG services via the PRTG Administration Tool. Then launch command prompt and run netstat -ano | find ":80"

The output will look similar to mine below, listing everything that is has 80 in the port being used. You are looking for something listening strictly on port 80, for example C:\WINDOWS\system32>netstat -ano | find ":80" TCP ESTABLISHED 14880 TCP LISTENING 16880 TCP ESTABLISHED 16880

The fifth column is the process id (PID) that you can then track down from task manager to see what the program is.

Hopefully this helps get you to the next step in troubleshooting.

Thanks, Randolfini

Created on Dec 14, 2017 2:47:48 PM

Last change on Dec 14, 2017 4:33:49 PM by  Dariusz Gorka [Paessler Support]



Thank you for chipping in, Randolfini. I would also suspect another process/service binding port 80 and netstat is the way to go to get down to the bottom of this.

Created on Dec 14, 2017 3:03:18 PM by  Erhard Mikulik [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.