I'm using plugin which gives me warning or crtis with established connections. If I run it on local machine it gives: *root@graber:/usr/lib/nagios/plugins# ./check_connections -w 1 -c 5 -C sshd CRITICAL Established connections: 6* I know, I run as root. But: Rights to the file: root@graber:/usr/lib/nagios/plugins# ls -all check_connections -rwxr-xr-x 1 nagios nagios 5459 2012-07-06 10:19 check_connections /etc/sudoers: root@graber:/usr/lib/nagios/plugins# cat /etc/sudoers Defaults env_reset root ALL=(ALL:ALL) ALL %admin ALL=(ALL) ALL nagios ALL=(ALL) NOPASSWD: /usr/bin/lsof nagios ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/ /etc/nagios/nrpe.cfg: *nrpe_user=nagios nrpe_group=nagios* *dont_blame_nrpe=1* *command_prefix=/usr/bin/sudo command[check_connections]=/usr/lib/nagios/plugins/check_connections -w 1 -c 5 -C sshd* log from remote: *2012-07-06T11:12:49+02:00 graber nrpe[25928]: Handling the connection... 2012-07-06T11:12:49+02:00 graber nrpe[25928]: Host address is in allowed_hosts 2012-07-06T11:12:49+02:00 graber nrpe[25928]: Host is asking for command 'check_connections' to be run... 2012-07-06T11:12:49+02:00 graber nrpe[25928]: Running command: /usr/lib/nagios/plugins/check_connections -w 1 -c 5 -C sshd 2012-07-06T11:19:11+02:00 graber nrpe[26100]: Return Code: 2, Output: NRPE: Unable to read output* Why is this happening? I'm out of ideas, I've searched google for 2 days now :)