AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 219

A company is running its application servers on Amazon EC2 instances. The EC2 instances run in separate VPCs that are connected by a transit gateway. The EC2 instances launch in a private subnet with a route to the transit gateway for internal and external connectivity. The external connectivity is provided by a VPC with firewall devices that perform an inspection for packets that ingress and egress through an internet gateway.

A network engineer needs to help the company’s application team increase the payload size per packet delivery between the EC2 instances. All network connectivity must be through the transit gateway

What should the network engineer do to meet these requirements?

Answer options

• A. Enable jumbo frames on the transit gateway. Instruct the application team to set the maximum transmission unit (MTU) of the system’s network interfaces to 9001 bytes.
• B. Instruct the application team to set the maximum transmission unit (MTU) of the VPC to 8500 bytes.
• C. Instruct the application team to set up enhanced networking on the system by using the enhanced networking adapter. Set the maximum transmission unit (MTU) to 9001 bytes.
• D. Instruct the application team to set the maximum transmission unit (MTU) of the system’s network interfaces to 8500 bytes.

Correct answer: D

Explanation

The correct answer is D because configuring the MTU of the system's network interfaces to 8500 bytes allows for larger packet sizes without fragmentation while maintaining compatibility with standard Ethernet frames. Options A and C suggest increasing the MTU to 9001 bytes, which may not be supported across all devices in the network path. Option B suggests changing the VPC MTU, which does not directly impact the EC2 instances' packet size configuration.