200-201 Security Concepts Practice Question
An attacker intercepts communication between a client and a server, allowing the attacker to read, insert, and modify messages in both directions. Which type of network attack is this?
⚠ Common exam trap
A common mix-up: candidates confuse MITM with specific techniques like ARP spoofing or DNS poisoning; the question describes the outcome, not the method.
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
✓
Man-in-the-middle
A man-in-the-middle (MITM) attack occurs when an attacker intercepts and relays communication between two parties, allowing them to read, insert, and modify messages. This matches the scenario exactly. The attacker positions themselves between the client and server, often without either party's knowledge.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Denial of Service
Why it's wrong here
A denial-of-service attack floods a target to exhaust resources and deny availability; it does not position the attacker between two parties to read and alter traffic. It would be the right answer if the scenario described service outage from traffic saturation rather than bidirectional interception and modification.
- ✗
ARP spoofing
Why it's wrong here
ARP spoofing poisons the local subnet's IP-to-MAC mappings, enabling interception only within that broadcast domain, not arbitrary bidirectional modification of a routed client-server session. It would be correct for LAN-level interception; the stem describes a general on-path man-in-the-middle attack.
- ✗
DNS poisoning
Why it's wrong here
DNS poisoning corrupts resolver cache entries to redirect name resolution to malicious IP addresses; it does not place the attacker inline to read, insert and modify bidirectional traffic. It would be correct for redirecting users to fraudulent sites, whereas this scenario describes an on-path man-in-the-middle attack.
- ✓
Man-in-the-middle
Why this is correct
A man-in-the-middle attack places the adversary between client and server, relaying traffic while reading, inserting and modifying messages in both directions. This active interception, rather than passive eavesdropping or denial of service, matches the bidirectional read-write-modify capability described in the scenario.
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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 Cisco exam blueprint
This 200-201 practice question is part of Courseiva's free Cisco 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 200-201 exam.