Minimizing Network Traffic on EC2 Instances with Enhanced Networking

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

To ensure that a minimal number of packets can be sent across the network interfaces of EC2 instances in a placement group with Enhanced Networking enabled, the MTU (Maximum Transmission Unit) setting needs to be adjusted. Therefore, option C is the correct answer.

Here's a detailed explanation of the answer:

A placement group is a logical grouping of instances within a single Availability Zone that enables applications to participate in a low-latency, 10 Gbps network. Enhanced Networking is a feature that enables high-performance networking capabilities on instances, such as increased packet per second (PPS) performance, lower network jitter, and lower latency.

To optimize network performance, it is recommended to set the MTU of the network interface to the maximum packet size supported by the network. MTU is the largest size of packet that a network protocol can transmit.

By setting the MTU to the maximum packet size, you can ensure that the network traffic is fragmented into the smallest number of packets, which reduces network overhead and improves network performance.

Option A, setting the Network Access Control List (NACL) to the maximum packet size, is incorrect because NACLs are used to control traffic to and from subnets and instances. They do not affect the MTU setting of network interfaces.

Option B, setting the Placement Group settings to the maximum packet size, is also incorrect because Placement Groups do not have any settings that relate to the MTU setting of network interfaces.

Option D, changing the Jumbo frame setting on the network interface for each instance, is also incorrect because Jumbo frames are used for sending larger packets than the standard MTU size, and it requires all network devices to support Jumbo frames. Jumbo frames may improve network performance, but it is not related to the goal of reducing the number of packets sent across the network interfaces.