Google PCA Manage implementation of cloud architecture Practice Question
This PCA practice question tests your understanding of manage implementation of cloud architecture. 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 is using Cloud NAT to allow private instances to access the internet. They notice that outbound connections are failing intermittently. 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.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The number of concurrent connections exceeds the Cloud NAT source port capacity for the assigned NAT IPs.
Cloud NAT uses source network address translation (SNAT) to map private instance IPs to a single public IP address. Each NAT IP has a limited pool of source ports (typically 64,512 per IP for TCP/UDP). When concurrent connections exceed this capacity, new outbound connections are dropped, causing intermittent failures. This is the most likely cause given the symptom of intermittent failures.
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.
✗
The private instances are using the wrong DNS server.
The number of concurrent connections exceeds the Cloud NAT source port capacity for the assigned NAT IPs.
Why this is correct
Cloud NAT has limited ports per public IP; exhaustion causes intermittent drops.
Clue confirmation
The clue word "most likely" 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
The trap here is that candidates confuse intermittent failures with firewall misconfigurations or DNS issues, but the key clue is 'intermittent'—which points to a resource exhaustion problem like port capacity, not a static policy or configuration error.
Detailed technical explanation
How to think about this question
Cloud NAT uses a deterministic port allocation algorithm: for each unique (source IP, source port, destination IP, destination port, protocol) tuple, it assigns a source port from the NAT IP's ephemeral range. When the port pool is exhausted, new connections receive a 'port allocation failure' and are silently dropped. In real-world scenarios, this often occurs during traffic spikes or when a single NAT IP serves many instances; adding more NAT IPs or using manual port ranges can mitigate the issue.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this PCA question in full detail.
Manage implementation of cloud architecture — This question tests Manage implementation of cloud architecture — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The number of concurrent connections exceeds the Cloud NAT source port capacity for the assigned NAT IPs. — Cloud NAT uses source network address translation (SNAT) to map private instance IPs to a single public IP address. Each NAT IP has a limited pool of source ports (typically 64,512 per IP for TCP/UDP). When concurrent connections exceed this capacity, new outbound connections are dropped, causing intermittent failures. This is the most likely cause given the symptom of intermittent failures.
What should I do if I get this PCA 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: "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?
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 PCA 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 PCA 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.