Your company needs to set up a VPN connection between its AWS VPC and its on-premises data center. There is a need to implement GRE VPN as the standard routing protocol. How would you implement this requirement?

Answer options:

A.Use AWS Managed VPN connections.
B.Use CloudHub VPN to create a secure VPN connection.
C.Create an EC2 instance and then use a software from the AWS Marketplace.
D.Use AWS Direct Connect.

Answer – C
Since there is a requirement to use a custom routing protocol instead of IPSec, the normal AWS VPN managed connections cannot be used. Instead, you have to decide to create an EC2 instance and use a custom VPN software from the AWS Marketplace. The below diagram from the AWS Documentation shows how this can be set up.
Options A and B are invalid because these don’t support the GRE protocol for encryption.
Option D is invalid because this should be used for direct connection between an AWS VPC and an on-premises data center.
For more information on Custom VPN connections, please refer to the below URL:
https://docs.aws.amazon.com/aws-technical-content/latest/aws-vpc-connectivity-options/software-vpn-network-to-amazon.html