We've recently set up Nagios on one of our Amazon EC2 instances to act as a monitoring server to our other instances. nrpe was installed on our staging server stager and appears to be working fine: monitoring_server~: /usr/lib/nagios/plugins/check_nrpe -H xx.xx.xx.xx -p 5666 NRPE v2.12 The issue is - when viewing the remote server stager within the Nagios admin screen - it appears to be 'DOWN'. The check_ping command reveals: monitoring_server~: /usr/lib/nagios/plugins/check_ping -H 'xx.xx.xx.xx' -w 5000,100% -c 5000,100% -p 1 PING CRITICAL - Packet loss = 100%|rta=5000.000000ms;5000.000000;5000.000000;0.000000 pl=100%;100;100;0 Can anyone provide some direction on how to get this working? Not sure what else to do