- A
Configure the health check to use the client IP as source.
Why wrong: Health checks use the load balancer's IP, not client IP.
- B
Enable Proxy Protocol on the load balancer.
Why wrong: Proxy Protocol is used for external load balancers that NAT; internal pass-through already preserves IP.
- C
Use a backend service with session affinity.
Why wrong: Session affinity does not affect client IP preservation.
- D
No configuration is needed; client IP is preserved by default.
Internal TCP/UDP LB is pass-through, so client IP is preserved automatically.
Question 103 of 1,000
PCNE Configuring Network Services Practice Question
This PCNE practice question tests your understanding of configuring network services. 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.
An organization has deployed an internal TCP/UDP load balancer in their VPC. They need to ensure that the load balancer preserves the client IP address when forwarding traffic to backend instances. Which configuration is required?
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
✓
No configuration is needed; client IP is preserved by default.
Internal TCP/UDP Load Balancers are pass-through load balancers (Layer 4). They preserve the client IP address by default because they forward packets directly without NAT. No special configuration is needed; the backend instances see the original source IP.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Configure the health check to use the client IP as source.
Why it's wrong here
Health checks use the load balancer's IP, not client IP.
- ✗
Enable Proxy Protocol on the load balancer.
Why it's wrong here
Proxy Protocol is used for external load balancers that NAT; internal pass-through already preserves IP.
- ✗
Use a backend service with session affinity.
Why it's wrong here
Session affinity does not affect client IP preservation.
- ✓
No configuration is needed; client IP is preserved by default.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
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.
Visual reference
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related PCNE NAT questions on configuration and troubleshooting.
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Configuring Network Services — study guide chapter
Learn the concepts, then practise the questions
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FAQ
Questions learners often ask
What does this PCNE question test?
Configuring Network Services — This question tests Configuring Network Services — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: No configuration is needed; client IP is preserved by default. — Internal TCP/UDP Load Balancers are pass-through load balancers (Layer 4). They preserve the client IP address by default because they forward packets directly without NAT. No special configuration is needed; the backend instances see the original source IP.
What should I do if I get this PCNE question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related PCNE NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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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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