AWS Certified Advanced Networking Specialty Practice Exam

In a transit VPC architecture, what is essential for enhancing inter-region communication?

1. VPN connections only

2. GRE tunneling between regions

3. Only using public IPs

4. Multiple transit gateways

The correct answer is: GRE tunneling between regions

In a transit VPC architecture, GRE (Generic Routing Encapsulation) tunneling plays a crucial role in enhancing inter-region communication. GRE is a tunneling protocol that encapsulates a wide variety of network layer protocols, effectively allowing secure and point-to-point communication over the Internet or other types of networks. By using GRE, organizations can create virtual point-to-point links to connect geographically diverse regions. This decouples the underlying physical network and makes it possible to transport packets from various protocols, not limited to IPv4 or IPv6. Consequently, GRE tunnels can support multicast traffic and provide a seamless way to interconnect different regions, facilitating complex networking scenarios and enhancing the overall interconnectivity of the cloud architecture. Moreover, GRE is beneficial in scenarios where organizations need to maintain a hybrid architecture, integrating on-premises networks with AWS regions via a unified method. This flexibility significantly enhances the ability to manage inter-region communication efficiently while supporting various data workloads. Other options, while they might provide connectivity, lack the specific benefits that GRE tunneling offers in terms of encapsulation and protocol diversity that is essential in a transit VPC designed for inter-region communication.