A company has two VPCs (VPC A and VPC B) in the `us-east-1` Region. An application running… — AWS Certified Solutions Architect - Associate

A company has two VPCs (VPC A and VPC B) in the `us-east-1` Region. An application running on Amazon EC2 instances in private subnets in VPC A needs to transfer $40\text{ TB}$ of data monthly to a database cluster in VPC B. Additionally, the EC2 instances in VPC A upload $15\text{ TB}$ of backup data to Amazon S3 daily. Currently, VPC A and VPC B are connected using an AWS Transit Gateway, and all external traffic from the private subnets, including the S3 backup traffic, is routed through a central NAT Gateway. A solutions architect needs to reduce data transfer costs.

Which combination of actions will meet these requirements most cost-effectively? (Select TWO.)

Create a Gateway VPC Endpoint for Amazon S3 in VPC A, and associate it with the route tables of the private subnets.Answer
Establish a VPC Peering connection between VPC A and VPC B, and route the traffic between the VPCs through the peering connection.Answer
C
Deploy an Interface VPC Endpoint for Amazon S3 in VPC A to route the backup traffic privately.
D
Route the Amazon S3 backup traffic through the existing AWS Transit Gateway to a NAT Gateway in VPC B.
E
Provision a NAT Instance in VPC A to replace the NAT Gateway, and route the Amazon S3 backup traffic through it.

Answer

Create a Gateway VPC Endpoint for Amazon S3 in VPC A and associate it with the route tables of the private subnets, and establish a VPC Peering connection between VPC A and VPC B and route the traffic between the VPCs through the peering connection.

To optimize costs, the solutions architect should address both the S3 backups and the cross-VPC data transfer. For S3, using a Gateway VPC Endpoint is free and bypasses the NAT Gateway data processing fees. For cross-VPC traffic, since there are only two VPCs in the same Region with high data volumes, VPC Peering is more cost-effective than AWS Transit Gateway because VPC Peering does not charge hourly or data processing fees.

Step-by-Step Solution

Analyze S3 backup data transfer costs.

15\text{ TB}

of data daily sent via a NAT Gateway incurs high NAT Gateway data processing charges (approx. $0.045 per GB).

Identifying the primary source of the data transfer cost is the first step to optimization.

Select the most cost-effective S3 routing option.

A Gateway VPC Endpoint for Amazon S3 is free to create and incurs no data processing charges, bypassing the NAT Gateway completely.

Replacing NAT Gateway routing with a Gateway VPC Endpoint for S3 traffic removes NAT Gateway processing fees.

Analyze cross-VPC data transfer costs.

40\text{ TB}

of monthly data transferred through AWS Transit Gateway incurs both hourly attachment fees and per-GB processing charges ($0.02 per GB).

Evaluating the Transit Gateway costs allows comparison with alternative routing options.

Select the most cost-effective cross-VPC routing option.

VPC Peering has no hourly charge and no data processing charges, charging only for standard data transfer rates between Availability Zones.

Replacing Transit Gateway with VPC Peering for a point-to-point connection between two VPCs in the same Region eliminates Transit Gateway data processing fees.

Key Concept

Data transfer cost optimization using Gateway VPC Endpoints for S3 and VPC Peering instead of NAT Gateway and Transit Gateway for high-volume point-to-point transfers.

Question

Answer

Step-by-Step Solution

Key Concept

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