I can't open port on my server with CloudLinux 9

Answered

ctorres

• March 21, 2025 15:40

Hello,

I have a server with cloudlinux 9 with Imunify360 and cPanel. I have the imunify configured so that all ports are open, but for some reason I need an app to run on port 8000 and this is not open, I have tried to see if there is any blocking, but I do not see anything.

In the iptables configuration is seen that there is no port limiting.

• 

  William Del Piero cPanel Staff

  • March 21, 2025 16:03

  Hi,

   

  What steps did you take to confirm the port is still blocked? For example, you can run nmap to scan port 8000 to check if port 8000 is still showing as 'filtered', as the 'filtered' status can indicate an external firewall is still blocking the port. You would need to run nmap from outside the server on the server's IP to check for an external firewall block. We have a guide for using nmap below:

   

  How to use nmap to troubleshoot port connectivity issues

   

  If you see a different status such as 'closed' that often indicates that no service is running on this port to handle the application's requests.

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  ctorres

  • March 21, 2025 16:35

  I just tested with nmap and it shows me the following:
  
  
  so you tell me I have an external firewall blocking the opening of the port, is that correct?

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  William Del Piero cPanel Staff

  • March 21, 2025 17:37

  Hi,

   

  Yes, a 'filtered' result from nmap often indicates that there is an external firewall blocking the port if you've already opened it in the local firewall/Imunify360. Did you have any other firewall management applications on the server such as CSF that could be overriding the Imunify360 settings? That could be another thing to check if you are able to confirm that an external firewall is not blocking this port.

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  ctorres

  • March 21, 2025 18:21

  I don't have any other firewall blocking, I only have imunify360 on the server.

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  William Del Piero cPanel Staff

  • March 21, 2025 19:32

  Hi,

   

  If Imunify360 is the only firewall application running on the server then I recommend reaching out to your service provider to see if they have this port blocked in an external firewall, as that is what the 'filtered' status returned from nmap indicates. We have a more detailed explanation about this below:

   

  What does the "filtered" status mean in an nmap report? 

   

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  ctorres

  • March 22, 2025 22:14

  muchas gracias

   

   

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  ctorres

  • March 22, 2025 22:14

  thank you to close this case

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