ANS-C01 Question 427
Select 3You are designing a hybrid architecture where on-premises resources connect to AWS via a Direct Connect connection. The on-premises network uses a default MTU (Maximum Transmission Unit) size of 1500 bytes, while the AWS Direct Connect connection supports jumbo frames with an MTU of 9001 bytes. To optimize bandwidth usage and minimize fragmentation, which actions should you take?
- A
Enable jumbo frames on your on-premises network devices and configure them to use an MTU of 9001 bytes.
- B
Configure your AWS Direct Connect virtual interface to use an MTU of 1500 bytes.
- C
Ensure that all intermediary network devices between your on-premises environment and AWS support an MTU of 9001 bytes.
- D
Use TCP MSS clamping to adjust the TCP segment size for traffic passing through the Direct Connect connection.
- E
Do nothing, as AWS Direct Connect automatically adjusts for MTU mismatches.
Show answer and explanation
Correct answers: A, C, D
Explanation
To optimize bandwidth and minimize packet fragmentation when using AWS Direct Connect, you should enable jumbo frames by configuring an MTU of 9001 bytes on both the on-premises network and the Direct Connect virtual interface. Additionally, all intermediary devices must support the larger MTU, and TCP MSS clamping can help ensure proper segment size alignment in case of mismatches. AWS Direct Connect does not automatically handle MTU mismatches, so proactive configuration is required.
- A. Correct.
Correct: Enabling jumbo frames on the on-premises network devices and configuring them to use an MTU of 9001 bytes allows you to take full advantage of the bandwidth optimization provided by AWS Direct Connect.
- B. Incorrect.
Incorrect: Configuring the AWS Direct Connect virtual interface to use an MTU of 1500 bytes would result in inefficient bandwidth usage as it does not leverage jumbo frames, which are supported by Direct Connect.
- C. Correct.
Correct: Ensuring that all intermediary network devices support an MTU of 9001 bytes is necessary to avoid packet fragmentation and to maintain end-to-end jumbo frame compatibility.
- D. Correct.
Correct: Using TCP MSS clamping helps adjust the TCP segment size to align with the MTU, preventing fragmentation in scenarios where mismatches occur.
- E. Incorrect.
Incorrect: AWS Direct Connect does not automatically adjust for MTU mismatches; you must explicitly configure the MTU and ensure compatibility across all components.