You monitor a remote server with Nagios or Icinga and see the following error in your Nagios/Icinga web interface:
CHECK_NRPE: Received 0 bytes from daemon. Check the remote server logs for error messages.
In /var/log/syslog on the remote server you see these messages:
Aug 23 14:20:20 server2 nrpe: Error: Request contained command arguments, but argument option is not enabled!
Aug 23 14:20:20 server2 nrpe: Client request was invalid, bailing out…
Open /etc/nagios/nrpe.cfg on the remote Nagios NRPE server…
… and set dont_blame_nrpe to 1:
[...] # COMMAND ARGUMENT PROCESSING # This option determines whether or not the NRPE daemon will allow clients # to specify arguments to commands that are executed. This option only works # if the daemon was configured with the --enable-command-args configure script # option. # # *** ENABLING THIS OPTION IS A SECURITY RISK! *** # Read the SECURITY file for information on some of the security implications # of enabling this variable. # # Values: 0=do not allow arguments, 1=allow command arguments dont_blame_nrpe=1 [...]
Save the file and restart the NRPE server: