In Portland, Oregon, ethical hacker Olivia Harper is hired by Cascade Biotech to test the...

The system described is a Network-Based Intrusion Detection System because it is positioned near the perimeter firewall and inspects traffic flowing across the network segment rather than activity on a single endpoint. In CEH-aligned coverage, a NIDS is deployed at strategic network points such as behind a firewall, on core switches, or on SPAN or TAP links to monitor inbound and outbound packets. Its purpose is to detect suspicious patterns, signatures, protocol anomalies, and indicators of scanning or exploitation attempts across multiple hosts and an entire subnet. The question explicitly says it “analyzes incoming and outgoing traffic” and looks for patterns “across the entire subnet,” which matches NIDS scope and placement.

A Host-Based IDS, by contrast, runs on individual servers or workstations and monitors local events such as system calls, logs, file integrity, registry changes, and local network connections for that specific host. That does not match the perimeter-positioned, subnet-wide traffic analysis described. Host-based firewalls also operate per endpoint, enforcing rules for that machine only, and do not provide centralized subnet-wide packet inspection from a perimeter vantage point. A network-based firewall primarily enforces allow or deny policy and may perform stateful filtering, but it is not primarily described as a detection tool analyzing suspicious patterns; IDS is the detection-focused control.

Therefore, Olivia is attempting to bypass a Network-Based Intrusion Detection System to demonstrate how malicious traffic might evade monitoring controls placed near the firewall and to help the security team strengthen detection coverage and alerting.