You’ve set up a set of EC2 Linux-based instances in a placement group. You’ve chosen instances with Enhanced Networking enabled. You want to ensure that a minimal number of packets can be sent across the network interfaces. How could you achieve this?

Answer options:

A.Set the Network Access Control List to the maximum network packet size.
B.Set the Placement Group settings to the maximum network packet size.
C.Change the MTU setting on the network interface for each instance.
D.Change the Jumbo frame setting on the network interface for each instance.

Answer – C
The AWS Documentation mentions on the MTU can be set for Linux-based instances.
Check and Set the MTU on Your Linux Instance
Some instances are configured to use jumbo frames, and others are configured to use standard frame sizes. You may want to use jumbo frames for network traffic within your VPC, or you may want to use standard frames for Internet traffic. Whatever your use case, we recommend verifying that your instance will behave the way you expect it to. You can use the procedures in this section to check your network interface`s MTU setting and modify it if needed.
To check the MTU setting on a Linux instance
You can check the current MTU value using the following IP command. Note that in the example output, MTU 9001 indicates that this instance uses jumbo frames.
To set the MTU value on a Linux instance
You can set the MTU value using the IP command. The following command sets the desired MTU value to 1500, but you could use 9001 instead.
2. (Optional) To persist your network MTU setting after a reboot, modify the following configuration files based on your operating system type.
Options A, B and D are all invalid because no such settings exist.
For more information on network MTU, please visit the following URL:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/network_mtu.html