Which of the following correctly describes a network-based IDS?

A network-based Intrusion Detection System (IDS) is designed to monitor and analyze network traffic, which involves capturing data packets that pass through network devices. It does this to identify any suspicious patterns or potential threats that might indicate malicious activities on the network. In this context, the correct choice describes how the IDS functions by logging suspicious activity, which is achieved by copying and analyzing the traffic flowing through the network.

Network-based IDS typically operates at various junctions of the network, such as routers or switches, allowing it to keep an eye on communications between different devices and detect anomalies or threats in real-time. By monitoring traffic patterns and logging data about this traffic, the IDS can alert network administrators to possible security incidents as they occur, facilitating rapid investigation and response to potential threats.

The other options do not accurately reflect the behavior and functionality of a network-based IDS. While host-based IDS might monitor only the host it is installed on, the network-based type encompasses a wider scope. Similarly, initiating active responses to threats is characteristic of Intrusion Prevention Systems (IPS) rather than pure IDS, which primarily focuses on detection and alerting. Lastly, operating independently of the network infrastructure is untrue since a network-based IDS fundamentally relies on the network to perform its monitoring