NRPE - Connection Refused Or Timed Out

Problem Description

This KB article addresses the following NRPE error:

Connection Refused Or Timed Out

Assumed Knowledge

The following KB article contains an explanation of how NRPE works and may need to be referenced to completely understand the problem and solution that is provided here:

NRPE - Agent and Plugin Explained

Troubleshooting The Error

This error is most often experienced when using the remote host as an NRPE proxy server to a network segment.

It can also be caused by using an incorrect IP address or DNS record in the check_nrpe command (rare in Nagios xi configurations). Double check the IP address, is it correct? If it is a DNS record, does it resolve to the correct IP address?

If you do use the remote host as an NRPE proxy, you may need to increase the maximum number of concurrent connections through xinetd. You need to add per_source = UNLIMITED to /etc/xinetd.d/nrpe.

Log onto your remote host at root and execute:

vi /etc/xinetd.d/nrpe

When using the vi editor, to make changes press i on the keyboard first to enter insert mode. Press Esc to exit insert mode.

Add the following line to the file inside the closing "}":

per_source=UNLIMITED

When you have finished, save the changes in vi by typing:

:wq

and press Enter.

Restart xinetd with the following command:

service xinetd restart

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

http://support.nagios.com/forum/