- A
Create a single Cloud NAT in the host project and share it
Why wrong: Incorrect. A single Cloud NAT in the host project cannot be managed by service projects, so it does not meet the requirement for service project autonomy.
- B
Use a NAT instance with an external IP in the host project and route traffic from service projects
Why wrong: Incorrect. A NAT instance does not allow service projects to manage their own Cloud NAT; it is a centralized solution that does not provide the desired autonomy.
- C
Create Cloud NAT in each service project with the same external IPs
Correct. Service projects can create their own Cloud NAT gateways using the same set of external IPs reserved in the host project, achieving both management autonomy and centralized IP control.
- D
Use Private Google Access with Cloud NAT in the host project
Why wrong: Incorrect. Private Google Access is for accessing Google APIs privately, not for outbound NAT, and does not address the requirement.
Shared VPC Cloud NAT: Centralized Outbound IP Control with NAT Instance
This PCNE practice question tests your understanding of cloud nat. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: cloud NAT. 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 is using Shared VPC with 100 service projects. They want to allow each service project to manage its own Cloud NAT, but the network administration team wants to control the outbound IP addresses used. What is the best design?
Quick Answer
The answer is to use a NAT instance with an external IP in the host project and route traffic from service projects. This design is correct because a NAT instance, deployed as a centralized egress point in the host project, allows the network administration team to attach a static external IP for centralized outbound IP control, while each service project retains autonomy to manage its own Cloud NAT configurations for internal traffic. On the Google Professional Cloud Network Engineer exam, this scenario tests your understanding of the trade-off between managed Cloud NAT and self-managed NAT instances within a Shared VPC hierarchy—a common trap is assuming Cloud NAT alone can delegate IP control to a central team, but Cloud NAT’s IP is per-region and per-project, not centrally managed. The key insight is that a NAT instance decouples IP ownership from NAT management. Memory tip: “Instance for IP, Cloud NAT for autonomy”—the instance owns the static IP, the service projects own their NAT rules.
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
Create Cloud NAT in each service project with the same external IPs
Option C is correct. In Shared VPC, Cloud NAT can be created in each service project, using the same set of external IP addresses. This allows service projects to manage their own NAT gateways (e.g., configure NAT rules and logging) while the network administration team controls the outbound IPs by reserving the IP addresses in the host project. The IPs can be shared across multiple NAT gateways across different service projects, as long as they are in the same region and the IPs are allocated from a common pool in the host project. Option A is wrong because a single Cloud NAT in the host project cannot be managed by service projects. Option B is wrong because a NAT instance does not allow service projects to manage their own Cloud NAT; it is a single instance managed centrally. Option D is wrong because Private Google Access is for accessing Google APIs privately, not for general outbound NAT.
Key principle: Cloud NAT
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Create a single Cloud NAT in the host project and share it
Why it's wrong here
Incorrect. A single Cloud NAT in the host project cannot be managed by service projects, so it does not meet the requirement for service project autonomy.
- ✗
Use a NAT instance with an external IP in the host project and route traffic from service projects
Why it's wrong here
Incorrect. A NAT instance does not allow service projects to manage their own Cloud NAT; it is a centralized solution that does not provide the desired autonomy.
- ✓
Create Cloud NAT in each service project with the same external IPs
- ✗
Use Private Google Access with Cloud NAT in the host project
Why it's wrong here
Incorrect. Private Google Access is for accessing Google APIs privately, not for outbound NAT, and does not address the requirement.
Common exam traps
Common exam trap: answer the scenario, not the keyword
A common misconception is that Cloud NAT must be created in the host project only. In reality, Cloud NAT can be created in service projects when using Shared VPC, and multiple NAT gateways can use the same external IP addresses, enabling both service project autonomy and centralized IP control.
Detailed technical explanation
How to think about this question
Under the hood, a NAT instance uses IP forwarding and iptables (or similar) to perform source NAT (SNAT), rewriting source IPs to the instance's external IP. Service projects must have routes (e.g., default route via the NAT instance's internal IP) and firewall rules to allow traffic. In contrast, Cloud NAT is a managed service using Andromeda software-defined networking, which cannot be delegated per service project for IP control. A real-world scenario is a multi-tenant SaaS provider where each tenant (service project) needs to configure NAT rules (e.g., port ranges) but the provider must enforce a single egress IP for whitelisting.
KKey Concepts to Remember
- Cloud NAT
- Shared VPC
- NAT IP sharing
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
Cloud NAT
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 cloud NAT, then practise related PCNE questions on the same topic to reinforce the concept.
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?
Cloud NAT
What is the correct answer to this question?
The correct answer is: Create Cloud NAT in each service project with the same external IPs — Option C is correct. In Shared VPC, Cloud NAT can be created in each service project, using the same set of external IP addresses. This allows service projects to manage their own NAT gateways (e.g., configure NAT rules and logging) while the network administration team controls the outbound IPs by reserving the IP addresses in the host project. The IPs can be shared across multiple NAT gateways across different service projects, as long as they are in the same region and the IPs are allocated from a common pool in the host project. Option A is wrong because a single Cloud NAT in the host project cannot be managed by service projects. Option B is wrong because a NAT instance does not allow service projects to manage their own Cloud NAT; it is a single instance managed centrally. Option D is wrong because Private Google Access is for accessing Google APIs privately, not for general outbound NAT.
What should I do if I get this PCNE question wrong?
Review cloud NAT, then practise related PCNE questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Cloud NAT
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 →
Keep practising
More PCNE practice questions
- An organization is migrating to Google Cloud and requires connectivity between their on-premises network and VPC. They p…
- A company is migrating on-premises DNS to Google Cloud. They have a hybrid network using Cloud VPN and want to resolve o…
- A network engineer is configuring a Cloud Router for BGP peering with an on-premises router over a VPN tunnel. The on-pr…
- A company uses Cloud NAT to allow private instances to reach the internet. They notice that egress traffic from Compute…
- You are setting up Partner Interconnect with a service provider that offers both Layer 2 and Layer 3 options. Your on-pr…
- Match each VPC networking concept to its definition.
Last reviewed: Jun 30, 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.