Best practice to handle service windows for passive checks in Nagios/Icinga

Question

With active checks, regular service windows can easily be handled using time periods and check intervals. How do you handle this for passive checks?

Answer 1

You can set an interval in which the passive check changes state if the server has not received any passive checks in that time interval. This is known as freshness in Nagios 3.0 terminology.

Nagios check freshness documentation

When the freshness interval expires w/o a passive check, naigos runs the "active" check for the service. You can set this to something like

check_command           check_dummy_fail!"No passive service notifications"

and you will be alerted just as if the passive check had failed. The tricky part is figuring out exactly what this interval should be.