Where is a host-based intrusion detection system located?

A host-based intrusion detection system (HIDS) is designed to monitor and analyze the behavior and activity on specific endpoints, such as individual computers or servers. It operates as an agent that is installed directly on the host machine, allowing it to observe system calls, file modifications, and anomalies to detect potential security threats or breaches.

This placement is essential because a HIDS can effectively monitor activities that take place internally on the device, which might not be visible to network-based systems. By focusing on the endpoint, it provides detailed insights into the state of the device, user behavior, and application performance.

In contrast, the other options involve monitoring tools that focus on network traffic rather than directly inspecting endpoint activities. For example, a dedicated proxy server is designed to inspect and manage traffic between clients and the internet, while a span or tap switch port would be used to capture and analyze network packets traversing the network. These approaches do not provide the targeted analysis required for detecting intrusions at the host level, which is the primary function of a host-based intrusion detection system.