Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A company has two VPCs in different AWS regions (us-east-1 and eu-west-1) that are peered. Applications in both VPCs need to communicate using private IP addresses. The ping tests are successful, but the latency is significantly higher than expected. Which change is most likely to improve the latency between the VPCs?
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
Best answer
Enable DNS resolution for the VPC peering connection.
Correct. When DNS resolution is enabled, instances can resolve private DNS names of instances in the peered VPC, ensuring traffic stays within the AWS backbone and avoids unnecessary hops or public internet routing.
B
Distractor review
Use a Transit Gateway instead of VPC Peering for cross-region connectivity.
Incorrect. Changing to Transit Gateway does not inherently improve latency; it adds a hub but traffic still traverses the AWS backbone.
C
Distractor review
Increase the MTU on the instances' network interfaces to 9001.
Incorrect. While jumbo frames can improve throughput, latency is not significantly affected by MTU changes.
D
Distractor review
Configure ECMP (Equal-Cost Multi-Path) routing on the VPC peering connection.
Incorrect. VPC Peering does not support ECMP; it is a one-to-one connection.
Common exam trap
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.
Technical deep dive
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.
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?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Enable DNS resolution for the VPC peering connection. — VPC Peering connections across regions do not support reflexive DNS resolution by default. By enabling 'DNS resolution' from the requester VPC and 'DNS hostname' in the accepter VPC, instances can resolve private DNS names of peered VPC instances, which may lead to more direct routing. However, cross-region VPC peering traffic is routed through AWS backbone, but DNS resolution can affect whether the private IP of the instance is used or if traffic goes via public internet. Increasing MTU might help but the issue is likely DNS resolution. Transit Gateway does not inherently reduce latency across regions. The ECMP (Equal-cost multi-path routing) is not applicable to VPC peering.
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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