SCS-C02 Question 268
Single answerAn organization is running a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The security team needs to troubleshoot intermittent connectivity issues reported by users. During the investigation, they identify that the issue occurs only when users upload large files. Which of the following TCP/IP concepts will most likely help the security team identify and resolve the issue?
- A
Maximum Transmission Unit (MTU) size
- B
TCP three-way handshake
- C
UDP packet loss
- D
DNS resolution time
Show answer and explanation
Correct answer: A
Explanation
The issue described in the scenario is likely caused by a mismatch or misconfiguration in the MTU size. When packets are larger than the MTU, fragmentation occurs, and if fragmentation is not handled correctly, it can lead to connectivity issues, especially with large file transfers. Understanding and analyzing MTU size is essential for troubleshooting such scenarios.
- A. Correct.
MTU size determines the maximum size of a packet that can be sent over the network without fragmentation. When large files are uploaded and the MTU is misconfigured, it can cause issues such as packet loss or delays, making this concept highly relevant to the scenario.
- B. Incorrect.
The TCP three-way handshake is used to establish a connection between a client and server, and it is not directly related to issues caused by large file uploads or MTU misconfigurations.
- C. Incorrect.
UDP packet loss is unrelated to this issue because the web application runs over TCP (as it involves reliable file uploads and connections). UDP is more relevant for use cases like streaming or DNS queries.
- D. Incorrect.
While DNS resolution time can cause delays in connecting to a web application, it is not relevant to troubleshooting issues that occur specifically during large file uploads.