Google PCA Design and plan a cloud solution architecture Practice Question
Exhibit
Refer to the exhibit.
gcloud compute instances create my-instance \
--zone=us-central1-a \
--machine-type=e2-micro \
--image-family=debian-11 \
--image-project=debian-cloud \
--boot-disk-size=20GB \
--boot-disk-type=pd-standard \
--network-interface=subnet=default,no-address \
--metadata=startup-script='#! /bin/bash
sudo apt-get update
sudo apt-get install -y nginx
sudo systemctl enable nginx
sudo systemctl start nginx'Refer to the exhibit. An architect created a VM instance using the above command. After the instance starts, the architect tries to access the nginx default page from the internet but gets a timeout. What is the most likely reason?
⚠ Common exam trap
Google Cloud often tests the distinction between connectivity failures caused by missing firewall rules (which produce connection refused or dropped packets) versus missing external IP addresses (which produce timeouts because the host is unreachable).
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 VM was created without an external IP address
The most likely reason for the timeout is that the VM was created without an external (public) IP address. Without an external IP, the VM is not directly reachable from the internet, even if nginx is running and firewall rules allow HTTP traffic. The timeout occurs because the internet has no route to the VM's private IP address.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The VM is in a subnet without a Cloud NAT
Why it's wrong here
Even with Cloud NAT, the VM has no external IP and cannot be accessed from the internet inbound.
- ✗
The firewall rule allowing HTTP traffic is missing
Why it's wrong here
The default VPC includes a default-allow-http firewall rule for port 80.
- ✗
The startup script failed to install nginx
Why it's wrong here
The startup script is correctly formatted and should install nginx successfully.
- ✓
The VM was created without an external IP address
Why this is correct
The 'no-address' flag omits the external IP, making the VM unreachable from the internet.
Go deeper
Related to this question
Learn chapter
Identity and Access Management (IAM)
Key term
HTTP
HTTP stands for Hypertext Transfer Protocol, the set of rules web browsers and servers use to communicate and transfer web pages over the internet.
Key term
Route
A route is a path that data takes through a network from one device or network to another, determined by routing protocols and configured rules.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA 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 PCA exam.