Exam AWS Certified Cloud Practitioner topic 1 question 109 discussion

The answer is C - TransitGateway. The more complicated topology is the more likely TransitGateway will be the answer.

C is correct. https://aws.amazon.com/transit-gateway/?whats-new-cards.sort-by=item.additionalFields.postDateTime&whats-new-cards.sort-order=desc AWS Transit Gateway connects VPCs and on-premises networks through a central hub. This simplifies your network and puts an end to complex peering relationships. It acts as a cloud router – each new connection is only made once.

AWS Transit Gateway is the best option for simplifying the management and reducing operational costs when interconnecting a large number of VPCs across multiple AWS accounts within a single AWS Region. AWS Transit Gateway acts as a central hub that connects multiple VPCs and on-premises networks, simplifying network management and routing. It also reduces the operational complexity and costs associated with managing many individual VPC peering connections.

B> AWS Transit Gateway simplifies the management of such a network by allowing the company to connect all their VPCs and on-premises networks through a central hub. This reduces operational complexity and can help lower costs by eliminating the need for multiple peering connections. Transit Gateway acts as a scalable and efficient solution for managing large-scale network architectures. Option C is disqualifies due to below restriction: By default, you can establish up to 50 active VPC peering connections per VPC in AWS. If needed, you can request an increase for this limit up to 125 active VPC peering connections per VPC. Refer https://docs.aws.amazon.com/vpc/latest/peering/vpc-peering-basics.html#vpc-peering-limitations

C because of the cost saving reason

Based on https://d1.awsstatic.com/whitepapers/building-a-scalable-and-secure-multi-vpc-aws-network-infrastructure.pdf Gateway vs VPC peering section, VPC peering achieves lower cost which is part of the question

VPC endpoints: Connect your VPC to supported AWS services without going over the internet. VPC peering: Connect two VPCs so that they can communicate with each other as if they were on the same network. Transit gateways: Connect your VPCs, on-premises networks, and VPN connections to a centralized hub.

https://docs.aws.amazon.com/vpc/latest/peering/what-is-vpc-peering.html Pricing for a VPC peering connection There is no charge to create a VPC peering connection. All data transfer over a VPC Peering connection that stays within an Availability Zone (AZ) is free. Charges apply for data transfer over a VPC Peering connections that cross Availability Zones and Regions. For more information, see Amazon EC2 Pricing. Transit Gateway maybe a better choice when "simplify management" is the only need, however, it's not free... Needs: interconnection + simplify management + reduce operational cost...... Thus, I'll stick with VPC peering connection.

Advantages of VPC peering Low cost since you need to pay only for data transfer. No bandwidth limit.

C. AWS Transit Gateway: AWS Transit Gateway is designed for connecting multiple VPCs, VPNs, and on-premises networks in a scalable and centralized manner, making it a suitable choice for simplifying management and reducing costs when interconnecting multiple VPCs. D. VPC peering: VPC peering is a way to connect two VPCs directly. While it's useful for connecting two VPCs, it doesn't scale well when you have thousands of VPCs to interconnect, and it doesn't provide centralized management and routing control across all the VPCs. So, for the scenario described, AWS Transit Gateway is the most appropriate choice.

A transit gateway enables you to attach VPCs and VPN connections in the same Region and route traffic between them. A transit gateway works across AWS accounts, and you can use AWS RAM to share your transit gateway with other accounts. After you share a transit gateway with another AWS account, the account owner can attach their VPCs to your transit gateway. A user from either account can delete the attachment at any time.

I'm sticking with D. VPC peering. VPC Peering and Transit Gateway are used to connect multiple VPCs. VPC Peering provides Full-mesh architecture while Transit Gateway provides hub-and-spoke architecture. Transit Gateway gives VPC connectivity at scale and simplifies VPC-to-VPC communication management over VPC Peering with a large number of VPCs. nowhere in the question does it say that they need to reach outside their network. only connect VPC's

C. AWS Transit Gateway "AWS Transit Gateway connects your Amazon Virtual Private Clouds (VPCs) and on-premises networks through a central hub. This connection simplifies your network and puts an end to complex peering relationships. Transit Gateway acts as a highly scalable cloud router—each new connection is made only once." https://aws.amazon.com/transit-gateway/

In question the below easily indicate the answer as Option C "The company has thousands of VPCs in a various AWS accounts that it wants to interconnect."

AWS Transit Gateway is the AWS service that can help simplify the management and reduce operational costs of interconnecting multiple VPCs (Virtual Private Clouds) spread across various AWS accounts in a single AWS Region. AWS Transit Gateway acts as a hub that allows for the centralization of network traffic between VPCs and on-premises networks. With AWS Transit Gateway, the pharmaceutical company can establish a single connection to the transit gateway and use it to efficiently route traffic between all the interconnected VPCs. By using AWS Transit Gateway, the company can simplify its network architecture, reduce the number of VPN connections or Direct Connect links required, and manage its network routing policies in a centralized manner. This simplification and consolidation of network connectivity can lead to operational cost savings and improved management efficiency.

Why Transit Gateway: AWS Transit Gateway connects VPCs and on-premises networks through a central hub. Why Not peering: Peering works for a small number of VPCs. Mainly if two VPCs. connecting peer-to-peer connection across multiple VPCs create a complex infrastructure which is difficult to manage and control.

C. AWS Transit Gateway