Which type of IDS can provide alerts on deviations from established norms in traffic behavior?

Anomaly-based Intrusion Detection Systems (IDS) function by monitoring network traffic and system activities to identify behaviors that deviate from predefined norms or baselines. This type of IDS is particularly effective because it does not rely on known attack signatures but instead adapts to the natural behavior of the network or system. By establishing a baseline of regular activity, anomaly-based IDS can recognize unusual patterns—such as spikes in traffic, abnormal data flows, or atypical user behavior—which may indicate a security threat, such as an intrusion or a malicious attack.

This capability makes anomaly-based IDS powerful for detecting zero-day attacks, where existing signature-based methods might fail due to the lack of a recognized signature. By focusing on behavioral changes, this system can alert administrators to potential risks that may not have been previously identified, thus enhancing the overall security posture.

In contrast, signature-based IDS relies on a database of known threat signatures to identify malicious activity. It is effective for known threats but cannot detect novel attacks that do not match existing signatures. Policy-based IDS focuses on specific rules and policies rather than behavior patterns, while host-based IDS monitors the activity on a single host rather than network-wide behavior. Therefore, anomaly-based IDS stands out for its ability to recognize deviations and alert on