AWS Certified Security – Specialty — Question 197

A company hosts an application on Amazon EC2 that is subject to specific rules for regulatory compliance. One rule states that traffic to and from the workload must be inspected for network-level attacks. This involves inspecting the whole packet.
To comply with this regulatory rule, a security engineer must install intrusion detection software on a c5n.4xlarge EC2 instance. The engineer must then configure the software to monitor traffic to and from the application instances.
What should the security engineer do next?

Answer options

• A. Place the network interface in promiscuous mode to capture the traffic.
• B. Configure VPC Flow Logs to send traffic to the monitoring EC2 instance using a Network Load Balancer.
• C. Configure VPC traffic mirroring to send traffic to the monitoring EC2 instance using a Network Load Balancer.
• D. Use Amazon Inspector to detect network-level attacks and trigger an AWS Lambda function to send the suspicious packets to the EC2 instance.

Correct answer: C

Explanation

The correct answer is C, as VPC traffic mirroring allows for the comprehensive inspection of network packets by duplicating the traffic and sending it to the monitoring instance. Option A is insufficient because promiscuous mode alone does not provide the necessary mirroring capability. Option B does not facilitate full packet inspection but rather focuses on flow logs, which are less detailed. Option D incorrectly suggests using Amazon Inspector, which is not designed for real-time traffic inspection.