As a SysOps Administrator, you have been asked to calculate the total network usage for all the EC2 instances of a company and determine which instance used the most bandwidth within a date range.

Which Amazon CloudWatch metric(s) will help you get the needed data?

Ref:

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/viewing_metrics_with_cloudwatch.html

Ans:

NetworkIn and NetworkOut - You can determine which instance is causing high network usage using the Amazon CloudWatch NetworkIn and NetworkOut metrics. You can aggregate the data points from these metrics to calculate the network usage for your instance.

NetworkIn - The number of bytes received by the instance on all network interfaces. This metric identifies the volume of incoming network traffic to a single instance.

The number reported is the number of bytes received during the period. If you are using basic (five-minute) monitoring and the statistic is Sum, you can divide this number by 300 to find Bytes/second. If you have detailed (one-minute) monitoring and the statistic is Sum, divide it by 60. Units of this metric are Bytes.

NetworkOut - The number of bytes sent out by the instance on all network interfaces. This metric identifies the volume of outgoing network traffic from a single instance.

The number reported is the number of bytes sent during the period. If you are using basic (five-minute) monitoring and the statistic is Sum, you can divide this number by 300 to find Bytes/second. If you have detailed (one-minute) monitoring and the statistic is Sum, divide it by 60. Units of this metric are Bytes.