- A
Create one VPN tunnel and a static route with next hop set to the VPN gateway.
Why wrong: A single tunnel provides no redundancy; if it fails, traffic is dropped. Static routes do not support automatic failover.
- B
Use Cloud Interconnect instead of VPN, and configure two VLAN attachments.
Why wrong: The question specifies Cloud VPN, not Cloud Interconnect. Also, VLAN attachments with Cloud Interconnect provide redundancy but are not VPN.
- C
Create two VPN tunnels to two separate peer VPN gateways on-premises, and use Cloud Router with BGP to advertise routes from both tunnels.
Cloud Router with BGP enables dynamic routing; with two tunnels, BGP will withdraw routes for the failed tunnel, and traffic will use the remaining tunnel automatically.
- D
Create two VPN tunnels to the same peer VPN gateway, and configure equal-cost multi-path (ECMP) routing with static routes.
Why wrong: Static routes require manual intervention to update routes when a tunnel fails. ECMP with static routes does not provide automatic failover.
PCNE Practice Question: Designing, planning, and prototyping a GCP network
This PCNE practice question tests your understanding of designing, planning, and prototyping a gcp network. 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 designing a hybrid network between their on-premises data center and Google Cloud. They need high availability for traffic between the two environments and want to use Cloud VPN with dynamic routing. Which configuration ensures that if one VPN tunnel fails, traffic automatically fails over to the other tunnel without manual intervention?
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 two VPN tunnels to two separate peer VPN gateways on-premises, and use Cloud Router with BGP to advertise routes from both tunnels.
Option C is correct because it uses two VPN tunnels to separate on-premises peer gateways with Cloud Router and BGP. BGP automatically handles failover by withdrawing routes from the failed tunnel and advertising routes via the healthy tunnel, ensuring traffic fails over without manual intervention. This meets the high availability and dynamic routing requirements specified in the question.
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.
- ✗
Create one VPN tunnel and a static route with next hop set to the VPN gateway.
Why it's wrong here
A single tunnel provides no redundancy; if it fails, traffic is dropped. Static routes do not support automatic failover.
- ✗
Use Cloud Interconnect instead of VPN, and configure two VLAN attachments.
- ✓
Create two VPN tunnels to two separate peer VPN gateways on-premises, and use Cloud Router with BGP to advertise routes from both tunnels.
Why this is correct
Cloud Router with BGP enables dynamic routing; with two tunnels, BGP will withdraw routes for the failed tunnel, and traffic will use the remaining tunnel automatically.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Create two VPN tunnels to the same peer VPN gateway, and configure equal-cost multi-path (ECMP) routing with static routes.
Why it's wrong here
Static routes require manual intervention to update routes when a tunnel fails. ECMP with static routes does not provide automatic failover.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume two tunnels to the same peer gateway (Option D) provide high availability, but they fail to recognize that the peer gateway itself is a single point of failure, and static routes with ECMP do not support automatic failover without BGP.
Detailed technical explanation
How to think about this question
Cloud Router uses BGP to exchange routes between the VPC and on-premises network. When a VPN tunnel fails, BGP session goes down, and Cloud Router automatically withdraws the routes learned via that tunnel, causing traffic to use the remaining tunnel. For true high availability, the two peer VPN gateways should be in different failure domains (e.g., different routers or locations) to avoid a single point of failure. BGP timers (e.g., hold time of 120 seconds) can be tuned for faster convergence.
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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this PCNE question test?
Designing, planning, and prototyping a GCP network — This question tests Designing, planning, and prototyping a GCP network — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create two VPN tunnels to two separate peer VPN gateways on-premises, and use Cloud Router with BGP to advertise routes from both tunnels. — Option C is correct because it uses two VPN tunnels to separate on-premises peer gateways with Cloud Router and BGP. BGP automatically handles failover by withdrawing routes from the failed tunnel and advertising routes via the healthy tunnel, ensuring traffic fails over without manual intervention. This meets the high availability and dynamic routing requirements specified in the question.
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.
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 →
Last reviewed: Jun 11, 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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