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

"Read timed out" when sending a command on port sensor



I have a PRTG port sensor that I'm using to make sure a particular port is open. It works fine.

I want to add the option to send a command and check the response. In a normal telnet window, I can enter the command and get a response back.

When I have the sensor send the same command, it gives a "read timed out" error. I have "write sensor result to disk" selected, and when I open the log file, I can see that the sensor received the expected response from the server. So why is the sensor giving me a timeout error?

port prtg timeout

Created on Feb 11, 2019 5:35:28 PM

1 Reply



Hello there,

Please note: When checking the response code, the service must return an integer code. Text codes (as returned by a POP3 service) will trigger an error in this case.

If you want us to check your settings, please open a ticket at [email protected] and provide us with a screenshot of the Sensor settings and the results files.

Kind regards,
Birk Guttmann, Tech Support Team

Created on Feb 12, 2019 12:08:39 PM by  Birk Guttmann [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.