Question 772 of 1,020
Network Configuration ConceptshardMultiple ChoiceObjective-mapped

Quick Answer

The answer is a duplex mismatch between the switch port and the NIC. This occurs because the switch port is manually locked to 10 Mbps half-duplex, while the NIC is set to auto-negotiation; when one side is fixed and the other is set to auto, the auto-negotiation process fails, forcing the NIC to fall back to half-duplex as well, but often at a mismatched speed, causing excessive collisions and retransmissions that spike latency. On the CompTIA A+ Core 1 220-1201 exam, this scenario tests your understanding of how slow network performance can stem from physical layer misconfigurations rather than IP issues—notice that pinging the local gateway is fast, but crossing the switch to another device is slow, a classic sign of duplex mismatch. A common trap is to blame the IP configuration or a bad cable, but the real culprit is the half-duplex bottleneck. Memory tip: “Half-duplex is half the conversation—one talks, one waits, and latency accumulates.”

220-1101 Network Configuration Concepts Practice Question

This 220-1201 practice question tests your understanding of network configuration concepts. 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 slow network connection for a user. The user's computer has an IP address of 192.168.1.100, subnet mask 255.255.255.0, and default gateway 192.168.1.1. The technician runs a ping to the gateway and gets replies with times around 2ms. However, pinging a server at 192.168.1.200 results in times over 500ms. The technician checks the switch and finds that the port for the user's computer is set to 10 Mbps half-duplex, while the computer's NIC is set to auto-negotiation. What is the most likely cause of the high latency?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "most likely"

    Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

Question 1hardmultiple choice
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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

There is a duplex mismatch between the switch port and the NIC.

A mismatch in duplex and speed settings between the switch port and the NIC can cause performance issues. When one side is set to a fixed speed/duplex and the other is set to auto-negotiation, the auto side may fail to negotiate correctly, often resulting in half-duplex operation and high error rates, leading to high latency. The switch port is manually set to 10 Mbps half-duplex, while the NIC is auto-negotiating, likely resulting in a mismatch.

Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

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 server at 192.168.1.200 is overloaded.

    Why it's wrong here

    If the server were overloaded, pinging it might show high latency, but the issue is specific to this user's connection, not the server itself.

  • The user's computer has a faulty network cable.

    Why it's wrong here

    A faulty cable could cause errors, but the ping to the gateway is fine (2ms), suggesting the cable is not the primary issue.

  • There is a duplex mismatch between the switch port and the NIC.

    Why this is correct

    The switch port is set to 10 Mbps half-duplex, while the NIC is auto-negotiating. This often results in a mismatch where the NIC runs at half-duplex, causing collisions and high latency.

    Clue confirmation

    The clue word "most likely" in the question point toward this answer.

    Related concept

    CIDR notation defines the prefix length.

  • The default gateway is misconfigured.

    Why it's wrong here

    The ping to the gateway is fast, so the gateway is working correctly. The issue is with the path to the server, likely due to the duplex mismatch.

Common exam traps

Common exam trap: usable hosts are not the same as total addresses

Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.

Trap categories for this question

  • Command / output trap

    If the server were overloaded, pinging it might show high latency, but the issue is specific to this user's connection, not the server itself.

Detailed technical explanation

How to think about this question

Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.

KKey Concepts to Remember

  • CIDR notation defines the prefix length.
  • Block size helps identify subnet boundaries.
  • Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
  • The required host count determines the smallest suitable subnet.

TExam Day Tips

  • Write the block size before choosing the subnet.
  • Check whether the question asks for hosts, subnets or a specific address range.
  • Do not confuse /24, /25, /26 and /27 host counts.

Key takeaway

Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

Real-world example

How this comes up in practice

A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.

What to study next

Got this wrong? Here's your next step.

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 220-1201 subnetting questions on CIDR, address ranges, and subnet selection.

Related practice questions

Related 220-1201 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this 220-1201 question test?

Network Configuration Concepts — This question tests Network Configuration Concepts — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: There is a duplex mismatch between the switch port and the NIC. — A mismatch in duplex and speed settings between the switch port and the NIC can cause performance issues. When one side is set to a fixed speed/duplex and the other is set to auto-negotiation, the auto side may fail to negotiate correctly, often resulting in half-duplex operation and high error rates, leading to high latency. The switch port is manually set to 10 Mbps half-duplex, while the NIC is auto-negotiating, likely resulting in a mismatch.

What should I do if I get this 220-1201 question wrong?

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 220-1201 subnetting questions on CIDR, address ranges, and subnet selection.

Are there clue words in this question I should notice?

Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

What is the key concept behind this question?

CIDR notation defines the prefix length.

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Last reviewed: Jun 18, 2026

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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.