- A
IKE version is set to IKEv1 on one side
Why wrong: Both tunnels use the same gateway, so IKE version is consistent.
- B
The pre-shared keys are mismatched between the two tunnels
A common pitfall is using different PSKs for each tunnel; they must match on both sides.
- C
The second tunnel's peer IP is unreachable
Why wrong: If the peer IP were unreachable, the first tunnel would likely also be affected.
- D
BGP timers are inconsistent
Why wrong: BGP timers do not prevent tunnel establishment; they affect routing after tunnel is up.
Question 309 of 982
PCNE Implementing Hybrid Interconnectivity Practice Question
This PCNE practice question tests your understanding of implementing hybrid interconnectivity. 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 has deployed an HA VPN gateway in Google Cloud to connect to their on-premises network. They have configured two tunnels with IKEv2 and BGP. One tunnel is established, but the second tunnel is not coming up. What could be a likely cause?
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
✓
The pre-shared keys are mismatched between the two tunnels
Common issues include mismatched pre-shared keys or IKE versions. Since the first tunnel works, the configuration is mostly correct, but the second tunnel may have a different pre-shared key or PSK mismatch. Incorrect IKE version is less likely because both tunnels use the same gateway. BGP timers are usually consistent. Cloud VPN logs would help identify the root cause.
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.
- ✗
IKE version is set to IKEv1 on one side
Why it's wrong here
Both tunnels use the same gateway, so IKE version is consistent.
- ✓
The pre-shared keys are mismatched between the two tunnels
Why this is correct
A common pitfall is using different PSKs for each tunnel; they must match on both sides.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The second tunnel's peer IP is unreachable
Why it's wrong here
If the peer IP were unreachable, the first tunnel would likely also be affected.
- ✗
BGP timers are inconsistent
Why it's wrong here
BGP timers do not prevent tunnel establishment; they affect routing after tunnel is up.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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 healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
What to study next
Got this wrong? Here's your next step.
Identify which PCNE exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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Implementing Hybrid Interconnectivity — study guide chapter
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FAQ
Questions learners often ask
What does this PCNE question test?
Implementing Hybrid Interconnectivity — This question tests Implementing Hybrid Interconnectivity — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The pre-shared keys are mismatched between the two tunnels — Common issues include mismatched pre-shared keys or IKE versions. Since the first tunnel works, the configuration is mostly correct, but the second tunnel may have a different pre-shared key or PSK mismatch. Incorrect IKE version is less likely because both tunnels use the same gateway. BGP timers are usually consistent. Cloud VPN logs would help identify the root cause.
What should I do if I get this PCNE question wrong?
Identify which PCNE exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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: 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.
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