A legacy data processing solution is moved to EC2 instances in private subnets within one VPC. The solution uses Amazon S3 for input and output data and DynamoDB for state. VPC flow logs are collected. The solution uses a single NAT gateway to reach the internet to register a license at a vendor hostname. The company found NAT gateway charges (USE2-NatGateway-Bytes) are higher than expected. What should the network engineer do to identify and fix the issue? (Choose two.)

The high NAT Gateway charges indicate that traffic is unnecessarily flowing through it. Inspecting VPC flow logs (the correct answer) will show the source and destination IPs and ports for all network traffic, allowing the engineer to identify which specific traffic is using the NAT Gateway. This helps pinpoint the applications or services contributing to the high costs. Confirming that gateway VPC endpoints for Amazon S3 and DynamoDB exist and are associated with the route tables (the other correct answer) is crucial. Without these endpoints, traffic to S3 and DynamoDB from private subnets would traverse the NAT Gateway to reach these public AWS services, incurring significant data processing charges. Gateway endpoints allow this traffic to stay within the AWS network, bypassing the NAT Gateway. VPC Traffic Mirroring is for deep packet inspection and troubleshooting specific traffic flows, not for identifying overall NAT Gateway usage patterns or cost analysis. An AWS Cost and Usage Report provides billing details but doesn't explain why the charges are high or what traffic caused them. Restricting outbound security group rules is a good security practice but won't prevent S3/DynamoDB traffic from using the NAT Gateway if endpoints aren't configured.