What does an Intrusion Detection System (IDS) do?

An Intrusion Detection System (IDS) primarily focuses on monitoring and analyzing network traffic for suspicious activity and potential threats. Its main function is to log incidents, analyze permitted network traffic, and generate alerts when malicious behavior is detected. This capability allows network administrators to recognize and respond to various types of cyber threats, but an IDS does not take direct action to prevent intrusions, which is why it differs from an Intrusion Prevention System (IPS) that would actively block unauthorized access.

By focusing on the logging and analysis of network traffic, an IDS provides valuable insight into network activity, helping security teams to understand potential vulnerabilities and attack patterns. This analysis is crucial for improving overall security postures and responding effectively to security incidents.

The other options mischaracterize the role of an IDS. For instance, an IDS does not automatically prevent intrusions as that is not its function. It also does not filter traffic at the application layer, which is more typical of firewalls or specific application security solutions. Finally, establishing secure VPN connections is unrelated to the primary purpose of an IDS, which concentrates solely on detecting and reporting on intrusions.