AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 126

A company deploys a software solution on Amazon EC2 instances that are in a cluster placement group. The solution's UI is a single HTML page. The HTML file size is 1,024 bytes. The software processes files that exceed 1,024 MB in size. The software shares files over the network to clients upon request. The files are shared with the Don't Fragment flag set. Elastic network interfaces of the EC2 instances are set up with jumbo frames.

The UI is always accessible from all allowed source IP addresses, regardless of whether the source IP addresses are within a VPC, on the internet, or on premises. However, clients sometimes do not receive files that they request because the files fail to travel successfully from the software to the clients.

Which options provide a possible root cause of these failures? (Choose two.)

Answer options

• A. The source IP addresses are from on-premises hosts that are routed over AWS Direct Connect.
• B. The source IP addresses are from on-premises hosts that are routed over AWS Site-to-Site VPN.
• C. The source IP addresses are from hosts that connect over the public internet.
• D. The security group of the EC2 instances does not allow ICMP traffic.
• E. The operating system of the EC2 instances does not support jumbo frames.

Correct answer: B, C

Explanation

Options B and C are valid potential causes for the transmission failures because both on-premises routes (via Site-to-Site VPN and public internet) may encounter issues with file sizes exceeding the MTU, particularly with the Don't Fragment flag set. Option A is less likely since AWS Direct Connect typically handles larger file transfers efficiently. Options D and E are not directly related to the issue of file transmission failure under the specified conditions.