ANS-C01 Question 372
Select 2Your organization has deployed a multi-region application hosted in both the US-East-1 and EU-West-1 AWS Regions. The application uses an Amazon VPC with a Virtual Private Gateway (VGW) in each region and is connected through AWS Transit Gateway. Users in the US have reported high latency when accessing resources in the EU region. Upon investigation, you find that packets are being fragmented. What changes can you make to improve network performance while maintaining reachability?
- A
Adjust the Maximum Transmission Unit (MTU) setting on the Transit Gateway attachments to match the workload requirements.
- B
Enable jumbo frames by increasing the MTU of the underlying EC2 instances to 9001 bytes.
- C
Configure a Direct Connect gateway for the application to bypass the Transit Gateway.
- D
Ensure Path MTU Discovery (PMTUD) is enabled on all application endpoints and test its functionality.
- E
Use a VPN connection between the regions instead of the Transit Gateway to eliminate packet fragmentation.
Show answer and explanation
Correct answers: A, D
Explanation
Packet fragmentation often leads to increased latency and degraded performance. In this scenario, adjusting the MTU settings on the Transit Gateway attachments ensures that the packet size aligns with the network path, reducing fragmentation. Enabling Path MTU Discovery allows the network to dynamically discover the optimal packet size, further mitigating fragmentation issues. These solutions improve network performance while maintaining reachability.
- A. Correct.
Adjusting the MTU setting on the Transit Gateway attachments can help align the packet size with the network path, reducing the likelihood of fragmentation and improving performance.
- B. Incorrect.
Enabling jumbo frames by increasing the MTU on EC2 instances to 9001 bytes may not resolve the fragmentation issue unless the entire network path, including Transit Gateway, supports it. This is not guaranteed in this scenario.
- C. Incorrect.
Using a Direct Connect gateway does not directly address the packet fragmentation or latency issue related to MTU configuration. It also changes the architecture significantly.
- D. Correct.
Enabling Path MTU Discovery (PMTUD) ensures that the network dynamically identifies the optimal packet size for transmission, avoiding fragmentation and improving performance.
- E. Incorrect.
Using a VPN connection instead of Transit Gateway does not inherently resolve packet fragmentation issues and may introduce additional complexity or latency.