Which IDS operates by copying traffic through hardware installed on a network switch?

The correct choice for the type of IDS that operates by copying traffic through hardware installed on a network switch is Network-based IDS.

Network-based IDS (NIDS) focuses on monitoring and analyzing traffic across the network to detect unauthorized access, anomalies, and potential threats. By interfacing with a network switch, a NIDS can passively capture and analyze packets traveling through the network. This is usually done by leveraging techniques like port mirroring or SPAN (Switched Port Analyzer) to ensure that the IDS has visibility into all traffic that traverses the network.

This method is particularly effective for detecting attacks occurring over the network and enables the organization to have real-time visibility into its network environment without disrupting the normal flow of traffic. It can also provide insights into traffic patterns and detect vulnerabilities within the network.

The other options do not involve capturing network traffic in this manner. Host-based IDS monitors the activity on individual hosts or devices, Firewall IDS integrates with firewalls and emphasizes filtering traffic rather than monitoring it in detail, and Behavioral IDS focuses on recognizing unusual patterns in network traffic rather than being tied to specific hardware interfaces like those used in network switches.