Reverse Service Checks


Forgive me if this has been answered elsewhere. If it has, please point me there.

I’m trying to configure “reverse” checks for Nagios services. I would like to get notification for a service which it UP, as opposed to a service which transitions to a down state.

For example. I want to service define for my unix boxen that telnetd and ftpd are not turned on. I want to be notified if the service gets turned on.

How should I go about doing this?




Use a service check as normal i.e. define it to detect exactly what you DONT want e.g. to notify when the service is down, but couple it with negate - this flips the return codes so OK becomes CRITICAL and CRITICAL becomes OK.