Nagios Support Forum

What is difference between active and passive host/service checks?

# Active Host / Service Checks:
# Passive Host / Service Checks:


Kind regard

Active checks are run directly by Nagios against a remote host. Passive checks are run on a remote host, and the results are then submitted back to Nagios.

Active checks are generally easier to set up and manage, but passive checks are more useful or even indispensable in certain situations. Generally you should stick to active checks unless you have a reason not to.

Active checks are triggered on a timed basis by the Nagios server or a remote Host and send the information back to Nagios, passive checks only update to Nagios when their previous value changes. That is as basic as the explanation can get. For instance with NRPE, you can have nagios initiate a check which runs a script on a external Windows/Linux Host and when that script completes the data is returned to Nagios. And we will use SNMP for the passive check example, a temperature monitoring Node gets warmer than it was previously and it fires off a message to Nagios to update this value they are one way checks.