How to reduce "Data Processed by NAT Gateways" charges?

Hello Sushant,

First, determine the major sources of traffic through your NAT gateway. Then, consider the following strategies for reducing data transfer and processing charges.

• Determine whether the instances sending the most traffic are in the same Availability Zone as the NAT gateway. If they're not, create new NAT gateways in the same Availability Zone as the resource to reduce cross-AZ data transfer charges.

• Determine whether the majority of your NAT gateway charges are from traffic to Amazon Simple Storage Service (S3) or Amazon DynamoDB in the same Region. If they are, set up a gateway VPC endpoint. Route traffic to and from the AWS resource through the gateway VPC endpoint, rather than through the NAT gateway. There's no data processing or hourly charges for using gateway VPC endpoints.

• If most traffic through your NAT gateway is to AWS services that support interface VPC endpoints, then create an interface VPC endpoint for the services. See pricing details for interface VPC endpoints to determine the potential cost savings.

• If most of your internet traffic is destined to non-AWS resources, consider using an internet gateway for instances generating the highest traffic. Unlike NAT gateways, internet gateways give your instances direct internet access at no cost. Security groups and network access control lists can be configured to prevent unauthorized access to instances, depending on your security policies. For connectivity through internet gateways, instances must be in a public subnet and have a public IP or Elastic IP address associated with its network interface.

Note: You can set up alarms to monitor use of your NAT gateway in the future using Amazon CloudWatch.

Reference