- A
Use Cloud Armor with a WAF rule to block outbound traffic.
Why wrong: Cloud Armor is for load-balanced traffic, not for data exfiltration prevention.
- B
Configure VPC Service Controls with a service perimeter that includes the VPC and the Cloud Storage bucket.
This prevents data from leaving the perimeter, including copying to external networks.
- C
Set up Private Google Access and restrict IAM permissions to the bucket.
Why wrong: IAM alone does not prevent data exfiltration; users could still download data and send it elsewhere.
- D
Use Cloud NAT with a firewall rule that denies all egress except to Google APIs.
Why wrong: This still allows egress to Google APIs, which could be used to exfiltrate data.
Question 307 of 1,000
PCNE Implementing VPC Instances Practice Question
This PCNE practice question tests your understanding of implementing vpc instances. 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.
An organization needs to prevent exfiltration of data from a Cloud Storage bucket to external IPs. The bucket is accessed by Compute Engine instances in a VPC. The instances need to read and write data to the bucket but should not be able to copy data to external networks. Which combination of controls meets this requirement?
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
✓
Configure VPC Service Controls with a service perimeter that includes the VPC and the Cloud Storage bucket.
VPC Service Controls create a service perimeter that restricts data movement between Google services and external networks. Within the perimeter, data can flow between authorized services. IAM conditions can further restrict access based on context. This is the primary method to prevent data exfiltration from Google Cloud-managed services.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use Cloud Armor with a WAF rule to block outbound traffic.
Why it's wrong here
Cloud Armor is for load-balanced traffic, not for data exfiltration prevention.
- ✓
Configure VPC Service Controls with a service perimeter that includes the VPC and the Cloud Storage bucket.
Why this is correct
This prevents data from leaving the perimeter, including copying to external networks.
Related concept
Static NAT maps one inside address to one outside address.
- ✗
Set up Private Google Access and restrict IAM permissions to the bucket.
Why it's wrong here
IAM alone does not prevent data exfiltration; users could still download data and send it elsewhere.
- ✗
Use Cloud NAT with a firewall rule that denies all egress except to Google APIs.
Why it's wrong here
This still allows egress to Google APIs, which could be used to exfiltrate data.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related PCNE NAT questions on configuration and troubleshooting.
- →
Implementing VPC Instances — study guide chapter
Learn the concepts, then practise the questions
- →
Implementing VPC Instances practice questions
Targeted practice on this topic area only
- →
All PCNE questions
1,000 questions across all exam domains
- →
Google Professional Cloud Network Engineer study guide
Full concept coverage aligned to exam objectives
- →
PCNE practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCNE practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Configuring Network Services practice questions
Practise PCNE questions linked to Configuring Network Services.
Implementing Hybrid Interconnectivity practice questions
Practise PCNE questions linked to Implementing Hybrid Interconnectivity.
Managing, Monitoring, and Optimising Network Operations practice questions
Practise PCNE questions linked to Managing, Monitoring, and Optimising Network Operations.
Designing, Planning, and Prototyping a GCP Network practice questions
Practise PCNE questions linked to Designing, Planning, and Prototyping a GCP Network.
Implementing VPC Instances practice questions
Practise PCNE questions linked to Implementing VPC Instances.
Implementing network security practice questions
Practise PCNE questions linked to Implementing network security.
Implementing a Virtual Private Cloud practice questions
Practise PCNE questions linked to Implementing a Virtual Private Cloud.
PCNE fundamentals practice questions
Practise PCNE questions linked to PCNE fundamentals.
PCNE scenario practice questions
Practise PCNE questions linked to PCNE scenario.
PCNE troubleshooting practice questions
Practise PCNE questions linked to PCNE troubleshooting.
Practice this exam
Start a free PCNE practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this PCNE question test?
Implementing VPC Instances — This question tests Implementing VPC Instances — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Configure VPC Service Controls with a service perimeter that includes the VPC and the Cloud Storage bucket. — VPC Service Controls create a service perimeter that restricts data movement between Google services and external networks. Within the perimeter, data can flow between authorized services. IAM conditions can further restrict access based on context. This is the primary method to prevent data exfiltration from Google Cloud-managed services.
What should I do if I get this PCNE question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related PCNE NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 →
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.
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.