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. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 wants to connect on-premise to GCP via Cloud VPN with dynamic routing. They have two on-prem routers for redundancy. Which configuration ensures automatic failover?
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 using Cloud Router with BGP and the same ASN
Option C is correct because creating two VPN tunnels with Cloud Router using BGP and the same ASN on both on-prem routers enables dynamic routing and automatic failover. Cloud Router establishes BGP sessions with each on-prem router, and when both tunnels advertise the same routes with the same ASN, Cloud Router can detect a BGP session failure and automatically route traffic through the remaining healthy tunnel. This setup ensures seamless failover without manual intervention.
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 two VPN tunnels each with static routes pointing to the other router
Why it's wrong here
Static routes do not provide dynamic failover; manual intervention required.
✗
Create one VPN tunnel with BGP and two interfaces
Why it's wrong here
Single tunnel is a single point of failure.
✓
Create two VPN tunnels using Cloud Router with BGP and the same ASN
Why this is correct
This allows BGP to automatically fail over traffic if one peer goes down.
Related concept
Read the scenario before looking for a memorised answer.
✗
Create two VPN tunnels with BGP but different ASNs on each tunnel
Why it's wrong here
Different ASNs imply separate routing domains; failover not automatic.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think different ASNs provide better redundancy, but in GCP Cloud Router, the same ASN is required for proper ECMP and automatic failover, as different ASNs can cause routing loops or incomplete failover.
Detailed technical explanation
How to think about this question
Cloud Router uses BGP to exchange routes between GCP and on-prem networks. When two VPN tunnels are configured with the same ASN, Cloud Router treats them as equal-cost multipath (ECMP) routes, and if one BGP session goes down, the router automatically withdraws the routes from that session and relies on the remaining session. In contrast, different ASNs would cause Cloud Router to see two distinct BGP peers, potentially leading to suboptimal routing or failure to failover if one peer's routes are not withdrawn correctly. This behavior aligns with RFC 4271, where BGP path selection uses AS_PATH length and other attributes.
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
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
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.
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 using Cloud Router with BGP and the same ASN — Option C is correct because creating two VPN tunnels with Cloud Router using BGP and the same ASN on both on-prem routers enables dynamic routing and automatic failover. Cloud Router establishes BGP sessions with each on-prem router, and when both tunnels advertise the same routes with the same ASN, Cloud Router can detect a BGP session failure and automatically route traffic through the remaining healthy tunnel. This setup ensures seamless failover without manual intervention.
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 →
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 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.