OS: Ubuntu 12.10 Server 64bits I've installed Icinga, with ido2db, pnp4nagios and icinga-web (last release, following the instruction given in the documentation, installation with apt, etc). I am using icinga-web to monitor my hosts. For the moment, I have just my localhost, and all is perfect. I am trying to add a host and monitor it with NRPE (version 2.12): root@server:/etc/icinga# /usr/lib/nagios/plugins/check_nrpe -H client NRPE v2.12 The configuration looks good. I've created a file in /etc/icinga/objects/client.cfg as below on the server: root@server:/etc/icinga/objects# cat client.cfg define host{ use generic-host ; Name of host template to use host_name client alias client.toto address xx.xx.xx.xx } # Service Definitions define service{ use generic-service host_name client service_description CPU Load check_command check_nrpe_1arg!check_load } define service{ use generic-service host_name client service_description Number of Users check_command check_nrpe_1arg!check_users } And add in my /etc/icinga/commands.cfg: # this command runs a program $ARG1$ with no arguments define command { command_name check_nrpe command_line /usr/lib/nagios/plugins/check_nrpe -H $HOSTADDRESS$ -c $ARG1$ -a $ARG2$ } # this command runs a program $ARG1$ with no arguments define command { command_name check_nrpe_1arg command_line /usr/lib/nagios/plugins/check_nrpe -H $HOSTADDRESS$ -c $ARG1$ } But it does not work. These are the logs from the client: Dec 3 19:45:12 client nrpe[604]: Connection from xx.xx.xx.xx port 32641 Dec 3 19:45:12 client nrpe[604]: Host address is in allowed_hosts Dec 3 19:45:12 client nrpe[604]: Handling the connection... Dec 3 19:45:12 client nrpe[604]: Host is asking for command 'check_users' to be run... Dec 3 19:45:12 client nrpe[604]: Running command: /usr/lib/nagios/plugins/check_users -w -c Dec 3 19:45:12 client nrpe[604]: Command completed with return code 3 and output: check_users: Warning t hreshold must be a positive integer#012Usage:check_users -w -c Dec 3 19:45:12 client nrpe[604]: Return Code: 3, Output: check_users: Warning threshold must be a positive integer#012Usage:check_users -w -c Dec 3 19:44:49 client nrpe[32582]: Connection from xx.xx.xx.xx port 32129 Dec 3 19:44:49 client nrpe[32582]: Host address is in allowed_hosts Dec 3 19:44:49 client nrpe[32582]: Handling the connection... Dec 3 19:44:49 client nrpe[32582]: Host is asking for command 'check_load' to be run... Dec 3 19:44:49 client nrpe[32582]: Running command: /usr/lib/nagios/plugins/check_load -w -c Dec 3 19:44:49 client nrpe[32582]: Command completed with return code 3 and output: Warning threshold mu st be float or float triplet!#012#012Usage:check_load [-r] -w WLOAD1,WLOAD5,WLOAD15 -c CLOAD1,CLOAD5,CLO AD15 Dec 3 19:44:49 client nrpe[32582]: Return Code: 3, Output: Warning threshold must be float or float trip let!#012#012Usage:check_load [-r] -w WLOAD1,WLOAD5,WLOAD15 -c CLOAD1,CLOAD5,CLOAD15 Dec 3 19:44:49 client nrpe[32582]: Connection from xx.xx.xx.xx closed. Have you any ideas?