AWS Solutions Architect Associate Practice Test

What can be done to enable a legacy application in a VPC to access on-premises services without reconfiguration?

1. An AWS Direct Connect link between the VPC and the internal network.

2. An Internet gateway to allow a VPN connection.

3. An Elastic IP address on the VPC instance.

4. Entries in Amazon Route 53 that allow the instance to resolve its dependencies.

The correct answer is: An AWS Direct Connect link between the VPC and the internal network.

To enable a legacy application in a Virtual Private Cloud (VPC) to access on-premises services without needing to reconfigure the application itself, establishing an AWS Direct Connect link is the most efficient solution. AWS Direct Connect provides a dedicated network connection from the on-premises environment to the AWS VPC, which allows for seamless communication between the two networks. This dedicated line can enhance performance and reduce latency when compared to standard internet connections, providing a more stable and consistent networking experience. Additionally, using Direct Connect can simplify the network architecture, as it allows the legacy application to access on-premises resources as if they were part of the same network without the need to change application configurations. While the other options might seem viable, they do not effectively address the requirement of accessing on-premises services without reconfiguration. For instance, setting up an Internet gateway to facilitate a VPN connection typically requires additional network adjustments or configurations, and may introduce complexities that might require changes to the legacy application. An Elastic IP address allows an instance to be accessed over the internet but does not inherently provide access to private on-premises resources. Lastly, having entries in Amazon Route 53 allows instances to resolve domain names, but it does not create a direct connection to on-premises services