What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

Firewall Ports



I have a problem with a remote probe behind a Fortigate firewall. If all ports are open, I can reach the probe. if I only port 23 560 open, I can not reach the core probe. Telnet also will not work on the port. Has yet another port to be open?

firewall port remote-probe

Created on Jun 6, 2011 11:10:50 AM

4 Replies




by default it should only be port 23560 (unless a different port is setup in the Probe and Server Admin Tools). Please bear in mind that on "probe side" it's an outgoing-connection, so you need to open the port on the location of the PRTG Core Server.

best regards.

Created on Jun 6, 2011 3:01:47 PM by  Torsten Lindner [Paessler Support]



Sorry that I have not responded.

The port is 23 560 and that all other probes. On the remote probe the port is released, but it does not work. Only when all ports are open, it works.

So it seems, had as yet another port to be opened.

Created on Jun 28, 2011 12:50:37 PM




the probe needs to be able to reach the core server! On which side is the Fortigate firewall?

The remote probe initiates the communication, sending a request to the core server.

We assume that inside to outside communication on the port 23560 is possible.

On the core side the firewall has to accept TCP traffic on port 23560 and direct it to the core server.

That way, firewall settings only need to be done on the core server side if you do have multiple remote probes.

Created on Jul 3, 2011 8:25:28 AM by  Aurelio Lombardi [Paessler Support]



For a list of ports that PRTG requires, please see the article Which ports does PRTG use on my system?

Created on Sep 15, 2014 2:54:01 PM by  Gerald Schoch [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.