- A
Enable Cloud NAT logging
Correct: NAT logs record connection and allocation failures.
- B
Enable VPC Flow Logs on the subnet
Why wrong: Flow Logs show network flows but not NAT allocation failures.
- C
Use Packet Mirroring to capture NAT traffic
Why wrong: Packet Mirroring copies traffic but not NAT-specific logs.
- D
Use Firewall Insights to check for blocked traffic
Why wrong: Firewall Insights are for firewall rules, not NAT.
- E
Set up log-based metrics and alerts on NAT logs
Correct: Alerts on NAT logs can notify administrators of failures.
Question 85 of 1,000
PCNE Practice Question: Managing, Monitoring, and Optimising Network Operations
This PCNE practice question tests your understanding of managing, monitoring, and optimising network operations. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 uses Cloud NAT for outbound internet access from private instances. They want to monitor for connection failures due to NAT resource exhaustion. Which two steps should they take? (Choose two.)
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
✓
Enable Cloud NAT logging
Enable Cloud NAT logging to capture connection and allocation failures. Set up alerts on NAT logs to detect failures. VPC Flow Logs do not capture NAT-specific failures. Firewall Insights are for firewall rules. Packet Mirroring is not relevant.
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.
- ✓
Enable Cloud NAT logging
- ✗
Enable VPC Flow Logs on the subnet
Why it's wrong here
Flow Logs show network flows but not NAT allocation failures.
- ✗
Use Packet Mirroring to capture NAT traffic
Why it's wrong here
Packet Mirroring copies traffic but not NAT-specific logs.
- ✗
Use Firewall Insights to check for blocked traffic
- ✓
Set up log-based metrics and alerts on NAT logs
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
Flow Logs show network flows but not NAT allocation failures.
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.
Visual reference
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 PCNE subnetting questions on CIDR, address ranges, and subnet selection.
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Managing, Monitoring, and Optimising Network Operations — study guide chapter
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FAQ
Questions learners often ask
What does this PCNE question test?
Managing, Monitoring, and Optimising Network Operations — This question tests Managing, Monitoring, and Optimising Network Operations — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Enable Cloud NAT logging — Enable Cloud NAT logging to capture connection and allocation failures. Set up alerts on NAT logs to detect failures. VPC Flow Logs do not capture NAT-specific failures. Firewall Insights are for firewall rules. Packet Mirroring is not relevant.
What should I do if I get this PCNE 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 PCNE subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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Last reviewed: Jul 4, 2026
This PCNE practice question is part of Courseiva's free Google Cloud 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 PCNE exam.
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