Question 86 of 497

Quick Answer

The answer is BGP, as it is the only dynamic routing protocol supported by Google Cloud for site-to-site VPN tunnels. This is because Cloud VPN with dynamic routing relies on Border Gateway Protocol to exchange routes between the on-premises router and the Cloud Router, enabling route advertisement, automatic failover, and policy-based control across multiple tunnels. On the Google Professional Cloud Network Engineer exam, this concept often appears in scenario-based questions where a company needs to connect their on-premises data center to Google Cloud using a site-to-site VPN with dynamic routing, and the common trap is assuming protocols like OSPF or EIGRP are supported—they are not. BGP’s use here tests your understanding that Google Cloud’s hybrid connectivity mandates a path-vector protocol for route exchange, not an interior gateway protocol. A helpful memory tip: think of BGP as the “bridge” for cloud VPNs—it’s the only Border Gateway that works with Google’s Cloud Router.

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. 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.

A company wants to connect their on-premises data center to Google Cloud using a site-to-site VPN with dynamic routing. Which protocol should they use for route exchange?

Question 1easymultiple choice
Read the full VPN explanation →

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

BGP

C is correct because Cloud VPN with dynamic routing requires BGP (Border Gateway Protocol) to exchange routes between the on-premises router and the Cloud Router. BGP is the only dynamic routing protocol supported by Google Cloud for site-to-site VPN tunnels, as it allows route advertisement, failover, and policy-based control over multiple tunnels.

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.

  • OSPF

    Why it's wrong here

    OSPF is not supported by Cloud VPN.

  • Static routing

    Why it's wrong here

    Static routing is not dynamic; BGP is recommended for dynamic routing.

  • BGP

    Why this is correct

    BGP is used for dynamic route exchange in Cloud VPN.

    Related concept

    Read the scenario before looking for a memorised answer.

  • RIP

    Why it's wrong here

    RIP is not used in GCP Cloud VPN.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often assume OSPF or RIP are valid for dynamic routing in cloud VPNs because they are common in on-premises networks, but Google Cloud exclusively supports BGP for dynamic route exchange over site-to-site VPN tunnels.

Detailed technical explanation

How to think about this question

BGP (RFC 4271) is an exterior gateway protocol (EGP) that uses path-vector logic and supports attributes like AS_PATH and LOCAL_PREF for route selection and policy. In Google Cloud, Cloud Router establishes BGP sessions over the VPN tunnel, enabling the exchange of custom IP prefixes and automatic failover between redundant tunnels. A common subtlety is that BGP timers (e.g., keepalive and hold timers) must be consistent between peers, and Google Cloud uses a default hold time of 60 seconds.

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 cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

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.

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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: BGP — C is correct because Cloud VPN with dynamic routing requires BGP (Border Gateway Protocol) to exchange routes between the on-premises router and the Cloud Router. BGP is the only dynamic routing protocol supported by Google Cloud for site-to-site VPN tunnels, as it allows route advertisement, failover, and policy-based control over multiple tunnels.

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.

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Last reviewed: Jun 25, 2026

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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.