All, I need some clarification about Nagios host and service check relationship. I have no dependency defined. I have the following host and service defintion define host{ name foo use generic-host ; Inherit default values check_period 24x7 check_interval 0 max_check_attempts 2 notification_period 24x7 notification_interval 10 notification_enabled 0 check_command check_host_alive } define service { use basic-service hostname foo service_description ping servicegroups named check_command check-host-alive } if you look above, I have both service and host check_command is the same check ("check_host_alive"). Now host is not checking on regular time interval because I have the check_interval is set to "0". Lets say the service check fails, at this point would nagios perform on demand host check? Also would nagios show host status as down and service status as critical? Please advise on this. Thanks -- Cordially, Shadhin Rahman