Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A company has a VPC with public and private subnets. An Application Load Balancer (ALB) is deployed in the public subnets, and an Auto Scaling group of web servers is deployed in the private subnets. The web servers need to frequently make HTTPS requests to an external API. The API provider requires that all requests originate from a consistent set of static IP addresses for whitelisting. The SysOps administrator must ensure that outbound traffic from the web servers has static source IP addresses. Which solution should be implemented?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Place the web servers in public subnets and assign each instance an Elastic IP address.
This would give static IPs but exposes the instances directly to the internet, increasing the attack surface and going against the requirement for private subnets.
B
Best answer
Deploy a NAT gateway in a public subnet with an Elastic IP and route outbound traffic from the private subnets through the NAT gateway.
The NAT gateway provides a static Elastic IP for outbound traffic from private instances, fulfilling the requirement securely.
C
Distractor review
Create a VPC endpoint for the external API service.
VPC endpoints are only supported for AWS and some third-party services listed in AWS PrivateLink. Most external APIs do not support VPC endpoints.
D
Distractor review
Use AWS Global Accelerator to provide static IP addresses for outbound traffic.
Global Accelerator provides static IPs for inbound traffic to your application, not for outbound traffic from your instances.
Common exam trap
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.
Technical deep dive
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.
Related practice questions
Related SOA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A company uses Amazon CloudFront to deliver content to a global audience. The origin is an Application Load Balancer in us-east-1. The SysOps administrator wants to reduce costs by minimizing the number of requests that reach the origin server. Which action should the administrator take?
Question 2
A company runs a batch processing application on Amazon EC2 that runs for 2 hours every night. The workload can tolerate interruptions. Which EC2 purchasing option provides the lowest cost for this use case?
Question 3
A SysOps administrator needs to monitor the CPU utilization of an Amazon RDS DB instance and receive an alarm when CPU utilization exceeds 80% for 5 consecutive minutes. Which AWS service should be used to create this alarm?
Question 4
A company runs a critical web application on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The application uses session stickiness (sticky sessions) to maintain user sessions. The SysOps administrator notices that when instances are replaced during a scale-in or failure event, users lose their session data. The administrator needs to preserve session data across instance failures without losing stickiness benefits. What should the administrator do?
Question 5
A company runs a production web application on a single Amazon EC2 instance. The application experiences a predictable and steady workload 24/7. The SysOps administrator wants to minimize compute costs for this instance while ensuring it remains available during the expected workload. Which EC2 purchasing option should the administrator use?
Question 6
A company has a VPC with public and private subnets. The private subnets host application servers that need to make outbound HTTPS connections to the internet. The SysOps administrator must implement a solution that provides outbound internet connectivity while preventing inbound connections from the internet. Additionally, the solution must allow the company to control which domains the application servers can access. Which solution should the administrator implement?
FAQ
Questions learners often ask
What does this SOA-C02 question test?
CIDR notation defines the prefix length.
What is the correct answer to this question?
The correct answer is: Deploy a NAT gateway in a public subnet with an Elastic IP and route outbound traffic from the private subnets through the NAT gateway. — To provide static outbound IP addresses from private subnets, a NAT gateway with an Elastic IP can be used. The web servers route their internet-bound traffic through the NAT gateway, which has a static public IP. This IP can be whitelisted by the API provider. Placing web servers in public subnets with Elastic IPs would expose them directly to the internet, which is a security concern and not recommended. VPC endpoints are used for private connectivity to AWS services only. AWS Global Accelerator is for inbound traffic acceleration, not outbound.
What should I do if I get this SOA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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