SCS-C02 Question 269
Single answerYour organization has deployed an application on Amazon EC2 instances in a private subnet behind an Application Load Balancer (ALB). Users are reporting intermittent connectivity issues when accessing the application. Upon investigation, you find that the application uses UDP for certain real-time features. How should you address this issue while maintaining the security and functionality of the application?
- A
Replace the Application Load Balancer with a Network Load Balancer, as it supports UDP traffic.
- B
Switch the application to use TCP instead of UDP for all communications.
- C
Enable UDP passthrough on the Application Load Balancer.
- D
Deploy an AWS Global Accelerator to improve UDP traffic handling.
Show answer and explanation
Correct answer: A
Explanation
Application Load Balancers only support TCP-based protocols like HTTP, HTTPS, and WebSocket. For applications that rely on UDP, a Network Load Balancer is the appropriate choice, as it is designed to handle both TCP and UDP traffic. This solution ensures that the application's real-time features using UDP will work as expected while maintaining security and functionality.
- A. Correct.
Correct. Network Load Balancers (NLBs) support UDP traffic, whereas Application Load Balancers (ALBs) only support HTTP/HTTPS and WebSocket traffic, which are TCP-based. Replacing the ALB with an NLB is the appropriate solution for handling UDP traffic.
- B. Incorrect.
Incorrect. While switching to TCP may resolve the issue, this approach requires modifying the application, which can be time-consuming and might not be feasible depending on the application's design.
- C. Incorrect.
Incorrect. Application Load Balancers do not support UDP traffic, so there is no option to enable UDP passthrough. This is not a valid solution.
- D. Incorrect.
Incorrect. AWS Global Accelerator improves performance and routing for global applications but does not address the underlying limitation of UDP support in the Application Load Balancer.