You have VPC and EC2 Instances hosted in the subnet. You need to diagnose layer 4 traffic and see which requests are ACCEPTED and REJECTED. Which of the following would help in fulfilling this requirement?

Answer options:

A.Enabling CloudTrail
B.Installing IDS on each Instance
C.Enabling VPC Flow Logs
D.Using Cloudwatch logs

Answer – C
VPC Flow Logs can be used to fulfill this requirement. Below is a snippet from the AWS Documentation which shows the fields which get recorded in VPC Flow logs.
For more information on VPC Flow logs, please refer to the below URL
https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/flow-logs.html
Note:
The external devices can support only up to Layer 4 as given in the attached screenshot.
Also, note that VPC flow logs can be configured to support all the external devices` traffic to and fro from a VPC. Therefore, VPC flow logs is compliant with all the corresponding protocols that are represented in each and every layer till Layer 4.