# Getting started with the Security Engine tester

The Security Engines can be configured with periodic self-tests to make sure that each Engine, IPS engine, Layer 2 Engine, and Master Security Engine is functioning correctly.

The tester runs checks at certain intervals, depending on the state of the engine (online, offline, or standby). Depending on the result, the tester can turn the engine online or offline, send alerts, and send SNMP traps.

The tester has the following limitations:

- The tester also runs internal system tests that cannot be edited or disabled. These tests are meant for recognizing certain configuration problems and internal error conditions, such as nodes in the cluster having different policies.
- Tests cannot be run on Virtual Engines.