easyMultiple ChoiceObjective-mapped
ISC2 CC Practice Question: Is configuring a network intrusion detection…
A security engineer is configuring a network intrusion detection system (NIDS) to monitor traffic on a critical subnet. To minimize false positives, which of the following should the engineer baseline first?
⚠ Common exam trap
ISC2 often tests the distinction between anomaly-based and signature-based detection, and the trap here is that candidates mistakenly think vulnerability scans or firewall logs provide a sufficient baseline, when in fact only observed normal traffic patterns during representative periods (like peak hours) can minimize false positives in an anomaly-based NIDS.
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
✓
The normal traffic patterns during peak business hours
Baselining normal traffic patterns during peak business hours establishes a reference of legitimate network behavior, which is essential for a NIDS to distinguish benign anomalies from actual threats. Without this baseline, the NIDS may generate false positives by flagging legitimate peak-hour traffic spikes as malicious. This aligns with the principle that anomaly-based detection relies on a statistical model of normal activity to reduce noise.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The results of a recent vulnerability scan
Why it's wrong here
Vulnerability scans identify weaknesses, not traffic patterns.
- ✓
The normal traffic patterns during peak business hours
Why this is correct
Baseline normal traffic to identify anomalies.
- ✗
The latest attack signatures from the vendor
Why it's wrong here
Signatures detect known attacks but don't establish a baseline.
- ✗
The firewall logs from the past 24 hours
Why it's wrong here
Firewall logs show blocked traffic, not necessarily normal patterns.
Visual reference
Go deeper
Related to this question
Learn chapter
Introduction to Security Principles
Key term
Subnet
A subnet is a logical subdivision of an IP network, created by partitioning a larger network address space using subnet masks.
Key term
Baseline
A baseline is a documented starting point for the normal performance and behavior of a system, network, or component, used to detect changes and troubleshoot issues.
About these practice questions
One of 976 original CC practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.