Cisco Cyber Security Practice Exam

The correct answer is the Intrusion Detection System (IDS). An IDS is designed to monitor network traffic for suspicious activity and potential threats, but it does not take action on its own. Instead, it relies on alerts or notifications that inform security personnel or other devices when it detects unusual patterns or potential breaches.

In contrast to an IDS, an Intrusion Prevention System (IPS) can take proactive measures, such as blocking traffic or dropping malicious packets, indicating that it doesn't need additional devices to respond to an attack. Firewalls are established to control incoming and outgoing network traffic based on predetermined security rules, providing a direct line of defense against unauthorized access. A Virtual Private Network (VPN) serves primarily to create secure connections over public networks, protecting data in transit without actively detecting or responding to threats.

Therefore, the IDS, while valuable for detection and monitoring, requires assistance from other devices or human intervention to respond effectively to an attack.