PCNE Implementing network security Practice Question
This PCNE practice question tests your understanding of implementing network security. 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 security engineer wants to allow SSH access to a VM that has no external IP. The VM is in a VPC with IAP configured. What is the simplest way to enable secure SSH without a bastion host?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use Identity-Aware Proxy (IAP) TCP forwarding with the gcloud compute start-iap-tunnel command.
Identity-Aware Proxy (IAP) TCP forwarding allows secure SSH access to a VM without an external IP by tunneling traffic through the IAP service. The `gcloud compute start-iap-tunnel` command establishes an encrypted tunnel from your local machine to the VM via the IAP proxy, using the VM's internal IP and port 22. This eliminates the need for a bastion host or public IP while leveraging IAP's identity-based access controls.
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.
✓
Use Identity-Aware Proxy (IAP) TCP forwarding with the gcloud compute start-iap-tunnel command.
Why this is correct
IAP TCP forwarding provides secure access without external IPs.
Related concept
Read the scenario before looking for a memorised answer.
✗
Create a VPN tunnel to the VPC and SSH over the VPN.
Why it's wrong here
While possible, it's more complex than using IAP.
✗
Configure a SOCKS proxy on a bastion host.
Why it's wrong here
Less simple and requires a bastion host.
✗
Assign an external IP to the VM and use a firewall rule to restrict access.
Why it's wrong here
This defeats the requirement of no external IP.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the misconception that IAP is only for web-based access (HTTP/HTTPS) and not for TCP forwarding, causing candidates to overlook the `gcloud compute start-iap-tunnel` command as a valid solution for SSH without a bastion host.
Detailed technical explanation
How to think about this question
IAP TCP forwarding works by creating a WebSocket connection to the IAP service, which then proxies TCP traffic to the VM's internal IP using the Compute Engine metadata server for authentication and authorization. The tunnel uses the `gcloud compute start-iap-tunnel` command, which binds to a local port (e.g., 3389 for RDP or 22 for SSH) and forwards traffic through the IAP service, which validates the user's identity and permissions before allowing the connection. In real-world scenarios, this is critical for managing private VMs in a zero-trust model where no public IPs are allowed.
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 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.
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.
Implementing network security — This question tests Implementing network security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Identity-Aware Proxy (IAP) TCP forwarding with the gcloud compute start-iap-tunnel command. — Identity-Aware Proxy (IAP) TCP forwarding allows secure SSH access to a VM without an external IP by tunneling traffic through the IAP service. The `gcloud compute start-iap-tunnel` command establishes an encrypted tunnel from your local machine to the VM via the IAP proxy, using the VM's internal IP and port 22. This eliminates the need for a bastion host or public IP while leveraging IAP's identity-based access controls.
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.