Question 80 of 1,705
Network ImplementationmediumMultiple ChoiceObjective-mapped

ANS-C01 Network Load Balancer (NLB) Practice Question

This ANS-C01 practice question tests your understanding of network implementation. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. A key principle to apply: network Load Balancer (NLB). 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 is deploying a multi-tier web application across two AWS Regions. The application uses an Application Load Balancer (ALB) in each region, and traffic must be distributed to the closest healthy ALB using Route 53 latency-based routing. The application requires that clients maintain the same source IP address when the request is forwarded from the ALB to the backend targets. The backend targets are EC2 instances in private subnets. The company also needs to ensure that traffic between the ALB and targets stays within AWS. What should the company implement to meet these requirements?

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

Deploy a Network Load Balancer (NLB) in each region with targets in public subnets. Use Route 53 latency-based routing to the NLB.

Option A is correct because Network Load Balancer (NLB) preserves the client source IP by default, meeting the requirement for source IP preservation. Targets can be placed in public subnets, and traffic between the NLB and targets remains within the VPC, satisfying the condition that traffic stays within AWS. With an internet-facing NLB, Route 53 latency-based routing can be used to distribute traffic to the closest healthy NLB across regions. Options B, C, D, and E are incorrect: B incorrectly relies on an internal ALB with PrivateLink, which does not support Route 53 latency routing and does not preserve source IP; C and E use ALB, which does not preserve source IP; D uses Global Accelerator, which does not use Route 53 and does not preserve source IP when ALB is an endpoint.

Key principle: Network Load Balancer (NLB)

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Deploy a Network Load Balancer (NLB) in each region with targets in public subnets. Use Route 53 latency-based routing to the NLB.

    Why this is correct

    Correct: NLB preserves source IP, targets in public subnets stay within VPC, and Route 53 latency routing can point to NLB's DNS name.

    Related concept

    Network Load Balancer (NLB)

  • Deploy an internal ALB in each region. Place targets in private subnets. Use VPC endpoints for the ALB (AWS PrivateLink) and Route 53 latency-based routing to the VPC endpoint.

    Why it's wrong here

    Incorrect: Internal ALB with PrivateLink cannot be used with Route 53 latency routing, and PrivateLink does not preserve client IP.

  • Deploy an Application Load Balancer (ALB) with internet-facing scheme in each region. Use Route 53 latency-based routing to the ALB.

    Why it's wrong here

    Incorrect: Internet-facing ALB does not preserve source IP; traffic between ALB and targets uses private IPs, but client IP is lost.

  • Use AWS Global Accelerator with endpoints in each region. Attach the ALB as an endpoint and enable client IP preservation on the accelerator.

    Why it's wrong here

    Incorrect: Global Accelerator uses anycast IP, not Route 53 latency routing, and it does not preserve source IP when the endpoint is an ALB.

  • Deploy an ALB with internet-facing scheme in each region. Use Route 53 latency-based routing to the ALB. Place targets in public subnets to preserve source IP.

    Why it's wrong here

    Incorrect: Similar to C; ALB does not preserve source IP regardless of subnet placement.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap is that many candidates assume an Application Load Balancer (ALB) or Global Accelerator can preserve the client source IP. However, ALB terminates the client connection and does not preserve the source IP. Only Network Load Balancer (NLB) preserves the source IP by default. Additionally, Route 53 latency-based routing requires a DNS endpoint; NLB provides this with its DNS name.

Trap categories for this question

  • Similar concept trap

    Incorrect: Similar to C; ALB does not preserve source IP regardless of subnet placement.

Detailed technical explanation

How to think about this question

AWS PrivateLink for internal ALBs uses VPC endpoint services that map to the ALB's network interfaces, allowing traffic to flow through the AWS backbone without traversing the internet. When a client sends a request via a VPC endpoint, the ALB forwards it to targets with the original client IP preserved in the X-Forwarded-For header, but the source IP in the IP packet is the ALB's private IP—true source IP preservation requires the ALB to be configured with 'preserve_client_ip' enabled (supported only for internal ALBs). In a multi-region setup, Route 53 latency-based routing evaluates health checks and latency measurements to route traffic to the closest healthy VPC endpoint, ensuring optimal performance and fault tolerance.

KKey Concepts to Remember

  • Network Load Balancer (NLB)
  • Source IP Preservation
  • Route 53 Latency-Based Routing
  • Internet-Facing Load Balancer

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 Load Balancer (NLB)

Real-world example

How this comes up in practice

A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

Visual reference

192.168.1.0 /24 256 addresses (254 usable) 192.168.1.0 /25 Subnet A 128 addr (126 usable) 192.168.1.128 /25 Subnet B 128 addr (126 usable) Borrowing 1 bit from host portion creates 2 subnets (/25)

What to study next

Got this wrong? Here's your next step.

Review network Load Balancer (NLB), then practise related ANS-C01 questions on the same topic to reinforce the concept.

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FAQ

Questions learners often ask

What does this ANS-C01 question test?

Network Implementation — This question tests Network Implementation — Network Load Balancer (NLB).

What is the correct answer to this question?

The correct answer is: Deploy a Network Load Balancer (NLB) in each region with targets in public subnets. Use Route 53 latency-based routing to the NLB. — Option A is correct because Network Load Balancer (NLB) preserves the client source IP by default, meeting the requirement for source IP preservation. Targets can be placed in public subnets, and traffic between the NLB and targets remains within the VPC, satisfying the condition that traffic stays within AWS. With an internet-facing NLB, Route 53 latency-based routing can be used to distribute traffic to the closest healthy NLB across regions. Options B, C, D, and E are incorrect: B incorrectly relies on an internal ALB with PrivateLink, which does not support Route 53 latency routing and does not preserve source IP; C and E use ALB, which does not preserve source IP; D uses Global Accelerator, which does not use Route 53 and does not preserve source IP when ALB is an endpoint.

What should I do if I get this ANS-C01 question wrong?

Review network Load Balancer (NLB), then practise related ANS-C01 questions on the same topic to reinforce the concept.

What is the key concept behind this question?

Network Load Balancer (NLB)

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Last reviewed: Jun 11, 2026

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This ANS-C01 practice question is part of Courseiva's free Amazon Web Services 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 ANS-C01 exam.