Question 776 of 1,705
Network Management and OperationsmediumMultiple ChoiceObjective-mapped

ANS-C01 Network Management and Operations Practice Question

This ANS-C01 practice question tests your understanding of network management and operations. 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 company has a VPC with public and private subnets. The private subnets need to access the internet for software updates. The company has set up a NAT gateway in the public subnet. However, instances in the private subnet cannot reach the internet. What is the most likely cause?

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 1mediummultiple choice
Read the full NAT/PAT explanation →

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 private subnet route table does not have a route to the NAT gateway

Option B is correct because the private subnet route table must have a default route (0.0.0.0/0) pointing to the NAT gateway. Option A is wrong because NAT gateway does not need an internet gateway route; it uses the internet gateway of the public subnet. Option C is wrong because security group rules for outbound traffic are usually allowed by default. Option D is wrong because the NAT gateway is in the public subnet, so it has internet access; the issue is routing from private subnet.

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 NAT gateway does not have a route to the internet gateway

    Why it's wrong here

    NAT gateway in public subnet automatically uses the internet gateway; no explicit route needed.

  • The security group for the instances blocks outbound traffic

    Why it's wrong here

    Security groups allow outbound traffic by default unless explicitly denied.

  • The NAT gateway is not associated with an Elastic IP

    Why it's wrong here

    NAT gateway requires an Elastic IP, but the question implies it is set up, so this is likely not the issue.

  • The private subnet route table does not have a route to the NAT gateway

    Why this is correct

    Without a default route to the NAT gateway, traffic from private subnet cannot reach the internet.

    Clue confirmation

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

    Related concept

    CIDR notation defines the prefix length.

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.

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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.

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 ANS-C01 subnetting questions on CIDR, address ranges, and subnet selection.

Related practice questions

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FAQ

Questions learners often ask

What does this ANS-C01 question test?

Network Management and Operations — This question tests Network Management and Operations — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: The private subnet route table does not have a route to the NAT gateway — Option B is correct because the private subnet route table must have a default route (0.0.0.0/0) pointing to the NAT gateway. Option A is wrong because NAT gateway does not need an internet gateway route; it uses the internet gateway of the public subnet. Option C is wrong because security group rules for outbound traffic are usually allowed by default. Option D is wrong because the NAT gateway is in the public subnet, so it has internet access; the issue is routing from private subnet.

What should I do if I get this ANS-C01 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 ANS-C01 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 20, 2026

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This ANS-C01 practice question is part of Courseiva's free Amazon Web Services 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 ANS-C01 exam.