A security engineer is installing an IPS to block signature-based attacks in the environment.

To block signature-based attacks, the Intrusion Prevention System (IPS) must be in active mode. In this mode, the IPS can actively monitor and block malicious traffic in real time based on predefined signatures. This is the best mode to prevent known attack types from reaching the internal network.

Monitor mode and sensor mode are typically passive, meaning they only observe and log traffic without actively blocking it.

Audit mode is used for review purposes and does not actively block traffic​​​.