ISC2 CC Network Security Practice Question
An organization decides to implement a security control that can detect and block attacks in real-time by sitting inline in the network. Which of the following should be chosen to meet these requirements?
⚠ Common exam trap
Many exam-takers confuse detection with prevention: candidates see 'detect' and pick IDS, ignoring the requirement to 'block' inline, which only an IPS can satisfy.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Intrusion Prevention System (IPS)
An IPS is designed to sit inline in the traffic path, inspect packets in real time, and actively block malicious traffic by dropping or resetting connections. This matches the requirement to both detect and block attacks inline. An IDS only detects and alerts; it cannot block because it is not inline.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Intrusion Detection System (IDS)
Why it's wrong here
An IDS passively monitors copies of traffic and raises alerts; it cannot block, so it fails the inline prevention requirement. It is tempting because detection is half the goal, and an IDS would be correct where the requirement is monitoring and alerting on suspicious activity without disrupting traffic flow.
- ✓
Intrusion Prevention System (IPS)
Why this is correct
Correct. IPS is inline and can block.
- ✗
Packet filtering firewall
Why it's wrong here
A packet filtering firewall inspects only headers (IP addresses, ports, protocols) and cannot detect attack signatures or malicious payloads, so it fails real-time attack detection. It is tempting because it does sit inline and block, and it would be correct where the requirement is permitting or denying traffic by address and port.
- ✗
Honeypot
Why it's wrong here
A honeypot is a decoy system that lures and observes attackers; it neither sits inline nor blocks live traffic. It is tempting because honeypots gather threat intelligence, and one would be correct where the requirement is deceiving and studying adversaries rather than preventing attacks in real time.
Go deeper
Related to this question
Learn chapter
Network Security Components and Controls
Key term
IPS
An Intrusion Prevention System (IPS) is a network security device that monitors traffic in real time and automatically blocks threats before they reach your systems.
Key term
IDS
An IDS is a security system that monitors network or system traffic for suspicious activity and alerts administrators to potential threats, but does not actively block them.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISC2 exam blueprint
This CC practice question is part of Courseiva's free ISC2 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CC exam.