AWS Certified Solutions Architect – Associate (SAA-C02) — Question 162

A solutions architect is performing a security review of a recently migrated workload. The workload is a web application that consists of Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. The solutions architect must improve the security posture and minimize the impact of a DDoS attack on resources.
Which solution is MOST effective?

Answer options

• A. Configure an AWS WAF ACL with rate-based rules. Create an Amazon CloudFront distribution that points to the Application Load Balancer. Enable the WAF ACL on the CloudFront distribution.
• B. Create a custom AWS Lambda function that adds identified attacks into a common vulnerability pool to capture a potential DDoS attack. Use the identified information to modify a network ACL to block access.
• C. Enable VPC Flow Logs and store then in Amazon S3. Create a custom AWS Lambda functions that parses the logs looking for a DDoS attack. Modify a network ACL to block identified source IP addresses.
• D. Enable Amazon GuardDuty and configure findings written to Amazon CloudWatch. Create an event with CloudWatch Events for DDoS alerts that triggers Amazon Simple Notification Service (Amazon SNS). Have Amazon SNS invoke a custom AWS Lambda function that parses the logs, looking for a DDoS attack. Modify a network ACL to block identified source IP addresses.

Correct answer: A

Explanation

Answer A is the most effective because it incorporates AWS WAF with rate-based rules to directly mitigate DDoS attacks while routing traffic through CloudFront, which offers additional DDoS protection. The other options involve more complex setups and do not provide the same level of immediate protection against DDoS attacks as using WAF and CloudFront together.