SOA-C02 Networking and Content Delivery Practice Question
A SysOps administrator is setting up a Network Load Balancer (NLB) to handle millions of requests per second. The target group consists of EC2 instances that are in a single Availability Zone. Which of the following is a potential issue?
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
✓
If the single AZ becomes unavailable, the NLB will not automatically fail over to other AZs.
Option A is the correct answer because if the NLB is provisioned in a single Availability Zone (AZ) and that AZ fails, the NLB will not automatically fail over to other AZs, which is a potential issue for high availability. Option B is incorrect because an NLB can be associated with only one AZ. Option C is incorrect because the NLB can preserve the source IP address when using instance targets. Option D is incorrect because the NLB can handle high throughput even in a single AZ.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
If the single AZ becomes unavailable, the NLB will not automatically fail over to other AZs.
Why this is correct
If only one Availability Zone is configured, the NLB has a single load balancer node with an Elastic Network Interface in that AZ. When that AZ becomes unavailable, the NLB node itself and every registered target are unreachable simultaneously, so the NLB cannot re-route traffic elsewhere because no other AZ has an ENI or target group membership. Automatic failover to another AZ is only possible if at least one additional AZ is enabled and has healthy targets.
- ✗
The NLB cannot be associated with only one Availability Zone.
Why it's wrong here
An NLB can absolutely be associated with a single Availability Zone. During creation or later in the console, you can select one subnet in a single AZ as the target capacity; AWS does not impose a minimum number of AZs. The documentation explicitly allows one or more AZs, but using only one AZ sacrifices high availability, not feature support.
- ✗
The NLB cannot preserve the source IP address of the client.
Why it's wrong here
This is incorrect because NLB is a Layer 4 pass-through load balancer; it forwards TCP/UDP/TLS packets without rewriting the source IP header. The target instance sees the original client IP directly by default, and no proxy protocol is required for basic source IP preservation. ALB and CLB instead perform connection termination and typically rely on X-Forwarded-For.
- ✗
The NLB will not be able to handle the traffic volume due to the single AZ limitation.
Why it's wrong here
A single AZ does not impose a throughput limitation on NLB; each NLB node scales elastically to handle very high traffic, and NLB is designed for millions of requests per second even from one node. The real risk is that if that one AZ fails, capacity drops to zero because there is no second node or target location. Thus the statement confuses a scaling capability with an availability constraint.
Go deeper
Related to this question
About these practice questions
This SOA-C02 question is part of Courseiva's 1,169-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SOA-C02 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 SOA-C02 exam.