How to track AWS data transfer charges?

Question

I want help on understanding the AWS cost explorer graph to track the huge data transfer usage. I have noticed the AWS account bills for jan, Feb and March (till current date) where it is showing a huge data transfer charge as a bill line item (image attached AWS Bill line Item)

regional data transfer - in/out/between EC2 AZs or using elastic IPs or ELB

. Further i checked it in AWS Cost Explorer reports by applying Group by filter Region wise and can see that it has data transfer for each region but also for

No Region

, i am not able able to understand this bar graph (please see the image attached and yellow graph AWS Cost Explorer Reports Region Wise) with level "No Region".

Answer 1

A good starting point would be to enable VPC Flow Logs. VPC Flow Logs will show you where the source and destination of all the traffic within your VPC. After you've analysed the logs, you should have a good indication of where to begin investigating.

Out of context but adding it here as it might help you: for some services such as S3, you can enable object-level logging to help you understand what is accessing your objects, which could help you further understand why you're paying for data transfers.

You can avoid paying for data transfer charges between AWS services by using VPC Endpoints. VPC endpoints allow you to connect directly to the service rather than over the internet, which will avoid incurring extra data charges. More on VPC Endpoints here.