AWS Certified DevOps Engineer – Professional — Question 58

A company's DevOps engineer is working in a multi-account environment. The company uses AWS Transit Gateway to route all outbound traffic through a network operations account. In the network operations account, all account traffic passes through a firewall appliance for inspection before the traffic goes to an internet gateway.
The firewall appliance sends logs to Amazon CloudWatch Logs and includes event severities of CRITICAL, HIGH, MEDIUM, LOW, and INFO. The security team wants to receive an alert if any CRITICAL events occur.
What should the DevOps engineer do to meet these requirements?

Answer options

• A. Create an Amazon CloudWatch Synthetics canary to monitor the firewall state. If the firewall reaches a CRITICAL state or logs a CRITICAL event, use a CloudWatch alarm to publish a notification to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the security team's email address to the topic.
• B. Create an Amazon CloudWatch mettic filter by using a search for CRITICAL events. Publish a custom metric for the finding. Use a CloudWatch alarm based on the custom metric to publish a notification to an Amazon Simple Notification Service (Amazon SNS) topic. Subscribe the security team's email address to the topic.
• C. Enable Amazon GuardDuty in the network operations account. Configure GuardDuty to monitor flow logs. Create an Amazon EventBridge (Amazon CloudWatch Events) event rule that is invoked by GuardDuty events that are CRITICAL. Define an Amazon Simple Notification Service (Amazon SNS) topic as a target. Subscribe the security team's email address to the topic.
• D. Use AWS Firewall Manager to apply consistent policies across all accounts. Create an Amazon EventBridge (Amazon CloudWatch Events) event rule that is invoked by Firewall Manager events that are CRITICAL. Define an Amazon Simple Notification Service (Amazon SNS) topic as a target. Subscribe the security team's email address to the topic.

Correct answer: B

Explanation

The correct answer is B because it directly addresses the need to filter for CRITICAL events in the firewall logs and set up a custom metric that triggers a CloudWatch alarm for notifications. Option A is incorrect as it relies on a canary which is not necessary for log monitoring. Option C suggests using GuardDuty, which is not applicable for this firewall setup, and D focuses on Firewall Manager, which does not pertain to the specific logging requirements of the firewall appliance.