The answer is ARP (Address Resolution Protocol), because it is the protocol responsible for detecting and reporting IP address conflicts on a network. ARP works by mapping IP addresses to their corresponding MAC addresses, and when a duplicate IP exists, the protocol will receive conflicting ARP replies from two different MAC addresses for the same IP. This mismatch is how the conflict is identified and flagged, often triggering an alert on the operating system or network device. On the CompTIA A+ Core 1 220-1201 exam, this concept tests your understanding of Layer 2 troubleshooting, and a common trap is confusing ARP with DHCP, which assigns IPs but does not detect conflicts. A helpful memory tip: think of ARP as the network’s “address detective”—if two devices claim the same IP, ARP catches the liar by revealing two different MAC addresses for one IP.
220-1201 Network Protocols Practice Question
This 220-1201 practice question tests your understanding of network protocols. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A technician is troubleshooting a network where users intermittently lose connectivity to a critical database server. The technician notices that the server's IP address is being duplicated on the network. Which protocol is responsible for detecting and reporting this conflict?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
ARP
This question tests knowledge of ARP, which is used to map IP addresses to MAC addresses. When an IP address conflict occurs, ARP may show multiple MAC addresses for the same IP, and some operating systems or network devices can detect and report this via ARP.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
ARP
Why this is correct
ARP resolves IP to MAC; a duplicate IP causes ARP table instability, and some systems use ARP probes to detect conflicts.
Related concept
Read the scenario before looking for a memorised answer.
✗
DHCP
Why it's wrong here
DHCP assigns IP addresses but does not directly detect conflicts; however, DHCP servers can perform conflict detection using ping or ARP.
✗
ICMP
Why it's wrong here
ICMP is used for error reporting and ping, but not specifically for IP conflict detection.
✗
DNS
Why it's wrong here
DNS resolves hostnames to IP addresses; it does not detect IP conflicts.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 220-1201 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 220-1201 question in full detail.
Identify which 220-1201 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Network Protocols — This question tests Network Protocols — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: ARP — This question tests knowledge of ARP, which is used to map IP addresses to MAC addresses. When an IP address conflict occurs, ARP may show multiple MAC addresses for the same IP, and some operating systems or network devices can detect and report this via ARP.
What should I do if I get this 220-1201 question wrong?
Identify which 220-1201 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 220-1201 practice question is part of Courseiva's free CompTIA 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 220-1201 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.