- A
Use VPC Flow Logs to monitor traffic
Why wrong: Monitoring does not reduce costs.
- B
Assign external IPs to the instances
Why wrong: External IPs incur egress costs.
- C
Enable Private Google Access on the subnet
Correct: Private Google Access routes traffic to Google APIs via internal IPs, free of egress charges.
- D
Set up Cloud NAT for the instances
Why wrong: Cloud NAT uses external IPs and incurs egress costs.
Question 220 of 1,000
PCNE Practice Question: Managing, Monitoring, and Optimising Network Operations
This PCNE practice question tests your understanding of managing, monitoring, and optimising network operations. 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 wants to reduce egress costs for traffic going to Google APIs (e.g., Cloud Storage, BigQuery) from Compute Engine instances. Which configuration should they use?
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
✓
Enable Private Google Access on the subnet
Private Google Access allows instances without external IPs to reach Google APIs over the internal network, avoiding internet egress charges.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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 VPC Flow Logs to monitor traffic
Why it's wrong here
Monitoring does not reduce costs.
- ✗
Assign external IPs to the instances
Why it's wrong here
External IPs incur egress costs.
- ✓
Enable Private Google Access on the subnet
- ✗
Set up Cloud NAT for the instances
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
- CIDR notation defines the prefix length.
- Block size helps identify subnet boundaries.
- Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
- The required host count determines the smallest suitable subnet.
TExam Day Tips
- Write the block size before choosing the subnet.
- Check whether the question asks for hosts, subnets or a specific address range.
- Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related PCNE subnetting questions on CIDR, address ranges, and subnet selection.
- →
Managing, Monitoring, and Optimising Network Operations — study guide chapter
Learn the concepts, then practise the questions
- →
Managing, Monitoring, and Optimising Network Operations practice questions
Targeted practice on this topic area only
- →
All PCNE questions
1,000 questions across all exam domains
- →
Google Professional Cloud Network Engineer study guide
Full concept coverage aligned to exam objectives
- →
PCNE practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCNE practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Configuring Network Services practice questions
Practise PCNE questions linked to Configuring Network Services.
Implementing Hybrid Interconnectivity practice questions
Practise PCNE questions linked to Implementing Hybrid Interconnectivity.
Managing, Monitoring, and Optimising Network Operations practice questions
Practise PCNE questions linked to Managing, Monitoring, and Optimising Network Operations.
Designing, Planning, and Prototyping a GCP Network practice questions
Practise PCNE questions linked to Designing, Planning, and Prototyping a GCP Network.
Implementing VPC Instances practice questions
Practise PCNE questions linked to Implementing VPC Instances.
Implementing network security practice questions
Practise PCNE questions linked to Implementing network security.
Implementing a Virtual Private Cloud practice questions
Practise PCNE questions linked to Implementing a Virtual Private Cloud.
PCNE fundamentals practice questions
Practise PCNE questions linked to PCNE fundamentals.
PCNE scenario practice questions
Practise PCNE questions linked to PCNE scenario.
PCNE troubleshooting practice questions
Practise PCNE questions linked to PCNE troubleshooting.
Practice this exam
Start a free PCNE practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this PCNE question test?
Managing, Monitoring, and Optimising Network Operations — This question tests Managing, Monitoring, and Optimising Network Operations — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Enable Private Google Access on the subnet — Private Google Access allows instances without external IPs to reach Google APIs over the internal network, avoiding internet egress charges.
What should I do if I get this PCNE question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related PCNE subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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 →
Keep practising
More PCNE practice questions
- An organization is migrating to Google Cloud and requires connectivity between their on-premises network and VPC. They p…
- A company is migrating on-premises DNS to Google Cloud. They have a hybrid network using Cloud VPN and want to resolve o…
- A network engineer is configuring a Cloud Router for BGP peering with an on-premises router over a VPN tunnel. The on-pr…
- A company uses Cloud NAT to allow private instances to reach the internet. They notice that egress traffic from Compute…
- You are setting up Partner Interconnect with a service provider that offers both Layer 2 and Layer 3 options. Your on-pr…
- Match each VPC networking concept to its definition.
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.
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.