PCNE Configuring network services Practice Question
This PCNE practice question tests your understanding of configuring network services. 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 uses Cloud NAT for outbound internet access. Engineering notices that some VM instances fail to connect to external services during peak hours. The network engineer suspects port exhaustion. Which action would best mitigate this issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the number of NAT IP addresses assigned to the NAT gateway.
Port exhaustion occurs when the NATgateway runs out of available source ports to map outbound connections. Increasing the number of NAT IP addresses assigned to the gateway multiplies the available port range (each IP provides 64,512 ports), directly alleviating port exhaustion during peak traffic. This is the standard mitigation for port exhaustion in Cloud NAT.
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.
✗
Change the NAT type from standard to public.
Why it's wrong here
NAT types (public, private) do not affect port capacity.
✗
Enable TCP keepalive on the NAT gateway.
Why it's wrong here
TCP keepalive helps release idle connections but does not increase the total number of available ports.
✗
Reduce the number of NAT gateways in the region.
Why it's wrong here
Reducing NAT gateways decreases port capacity and makes exhaustion worse.
✓
Increase the number of NAT IP addresses assigned to the NAT gateway.
Why this is correct
More NATIPs provide additional source ports, alleviating exhaustion.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the misconception that reducing NAT gateways or changing NAT type solves port exhaustion, when the actual solution is increasing the number of NAT IP addresses to expand the available port range.
Detailed technical explanation
How to think about this question
Cloud NAT uses source network address translation (SNAT) to map VM internal IPs to external IPs, with each external IP offering up to 64,512 ephemeral source ports (per protocol: TCP, UDP, ICMP). When all ports are consumed, new connections fail. By adding more NAT IP addresses, you linearly increase the total port pool (e.g., 2 IPs = ~129,024 ports). This is analogous to increasing the number of public IPs in a traditional NAT pool to scale outbound concurrency.
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.
TExam Day Tips
→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 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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Configuring network services — This question tests Configuring network services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Increase the number of NAT IP addresses assigned to the NAT gateway. — Port exhaustion occurs when the NAT gateway runs out of available source ports to map outbound connections. Increasing the number of NAT IP addresses assigned to the gateway multiplies the available port range (each IP provides 64,512 ports), directly alleviating port exhaustion during peak traffic. This is the standard mitigation for port exhaustion in Cloud NAT.
What should I do if I get this PCNE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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.
Question Discussion
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