# Getting started with the NGFW Engine tester

The NGFW Engines can be configured with periodic self-tests to make sure that each Firewall, IPS engine, Layer 2 Firewall, and Master NGFW 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 NGFW Engines.