ISC2 CC Network Security Practice Question
Which security control would best mitigate the risk of network sniffing on a wired LAN segment?
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
✓
Using encryption protocols (e.g., IPsec, TLS)
Encrypting traffic (e.g., using HTTPS, VPN) makes sniffed data unreadable.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Using encryption protocols (e.g., IPsec, TLS)
Why this is correct
IPsec and TLS encrypt payloads end-to-end, so frames captured by a sniffer on the wired segment appear as ciphertext rather than readable credentials or data. Encryption directly defeats sniffing, whereas segmentation or port security only limit where an attacker can capture traffic.
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Implementing VLANs
Why it's wrong here
VLANs segment broadcast domains at Layer 2 but do not encrypt frames, so a host on the same VLAN can still capture traffic with a sniffer. VLANs are tempting because they limit broadcast scope and separate departmental traffic, which is their actual purpose.
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Disabling unused ports on the switch
Why it's wrong here
Disabling unused switch ports reduces the number of physical access points an attacker can plug into, but active ports still carry cleartext frames capturable by sniffing. It is tempting because port security blocks rogue devices, its real purpose, yet it does not protect traffic on live links.
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Deploying an intrusion detection system
Why it's wrong here
An IDS detects suspicious traffic patterns after sniffing has occurred; it cannot prevent a host from capturing frames on the segment. IDS deployment is tempting because it provides visibility and alerting for intrusions, which is its genuine role in a defence-in-depth architecture.
Go deeper
Related to this question
Learn chapter
Risk Management and Security Controls
Key term
Risk
Risk is the possibility that an event or action will negatively affect an organization's ability to achieve its goals, often measured in terms of likelihood and impact.
Key term
VPN
A VPN (Virtual Private Network) creates a secure, encrypted tunnel between your device and a remote server, protecting your data and hiding your online activity.
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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.