Problem Description
This KB article addresses the following NRPE error:
CHECK_NRPE: Error Receiving Data From Daemon
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 not to be confused with the error "CHECK_NRPE: Received 0 bytes from daemon" as they have separate causes.
Most often, this error is experienced when using the no ssl switch (-n) with check_nrpe even though NRPE on the remote host was compiled with ssl enabled. There are very few instances where NRPE is best run without ssl, so if you added the -n switch to your check for testing reasons, make sure to remove the switch before deploying the check. If you have a reason for not using ssl, do note that you will have to compile NRPE without ssl to avoid this error when using the -n switch. Detailed compile instructions can be found in the following KB article:
NRPE - How To Install NRPE v3 From Source
The other general cause of this error, though rare, happens when your check's check_nrpe timeout is set too low. To increase the timeout, refer to the following KB article:
NRPE - CHECK_NRPE: Socket Timeout After n Seconds
Final Thoughts
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