- A
The firewall rule is an egress rule instead of ingress
Why wrong: The rule is explicitly described as an ingress rule, so this is not the issue.
- B
The VM does not have the network tag 'web' assigned
Correct. The allow rule only applies to VMs with the network tag 'web'. If the VM does not have this tag, the rule does not apply, and the default deny blocks traffic.
- C
The priority of the allow rule is lower (higher number) than the deny rule
Why wrong: The allow rule has priority 1000, which is higher (lower number) than the deny rule at 65535, so priority is correctly configured.
- D
The VM has an external IP but the firewall rule only applies to internal IPs
Why wrong: Firewall rules apply to both internal and external IPs unless specifically restricted; there is no such restriction here.
PCNE Network Tags Practice Question
This PCNE practice question tests your understanding of implementing vpc instances. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: network Tags. 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.
An engineer is troubleshooting a firewall rule issue. A VM with network tag 'web' is unable to receive HTTP traffic from the internet. The VPC has an ingress firewall rule allowing tcp:80 from 0.0.0.0/0 to targets with tag 'web' at priority 1000. Another ingress rule denies all ingress traffic at priority 65535. What is the 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 VM does not have the network tag 'web' assigned
The allow rule targets VMs with network tag 'web'. If the VM does not have this tag, the rule does not apply, and the default deny ingress rule (priority 65535) blocks the HTTP traffic. The priority ordering is correct (allow at 1000 is higher than deny at 65535), but the tag mismatch prevents the allow rule from being effective.
Key principle: Network Tags
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 firewall rule is an egress rule instead of ingress
Why it's wrong here
The rule is explicitly described as an ingress rule, so this is not the issue.
- ✓
The VM does not have the network tag 'web' assigned
Why this is correct
Correct. The allow rule only applies to VMs with the network tag 'web'. If the VM does not have this tag, the rule does not apply, and the default deny blocks traffic.
Related concept
Network Tags
- ✗
The priority of the allow rule is lower (higher number) than the deny rule
Why it's wrong here
The allow rule has priority 1000, which is higher (lower number) than the deny rule at 65535, so priority is correctly configured.
- ✗
The VM has an external IP but the firewall rule only applies to internal IPs
Common exam traps
Common exam trap: answer the scenario, not the keyword
Candidates often overlook that firewall rules targeting network tags require those tags to be applied to the VM. Priority and rule direction are correctly configured in this scenario.
Detailed technical explanation
How to think about this question
Treat this as a scenario question. Identify the problem, the constraint, and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- Network Tags
- Firewall Rule Target
- Priority
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
Network Tags
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.
Review network Tags, then practise related PCNE questions on the same topic to reinforce the concept.
- →
Implementing VPC Instances — study guide chapter
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Implementing VPC Instances practice questions
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FAQ
Questions learners often ask
What does this PCNE question test?
Implementing VPC Instances — This question tests Implementing VPC Instances — Network Tags.
What is the correct answer to this question?
The correct answer is: The VM does not have the network tag 'web' assigned — The allow rule targets VMs with network tag 'web'. If the VM does not have this tag, the rule does not apply, and the default deny ingress rule (priority 65535) blocks the HTTP traffic. The priority ordering is correct (allow at 1000 is higher than deny at 65535), but the tag mismatch prevents the allow rule from being effective.
What should I do if I get this PCNE question wrong?
Review network Tags, then practise related PCNE questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Network Tags
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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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