Your company plans to create a Direct Connect connection and have a VPN as a backup connection. Which of the following must be done to ensure that the AWS Direct connect connection is the preferred path?

Answer options:

A.Ensure that prefixes are advertised the same on both connections.
B.Ensure that the longest prefix is advertised on AWS Direct connect.
C.Ensure that AS_PATH prepending is configured on AWS Direct Connect.
D.Ensure that the shortest prefix is advertised on AWS Direct connect.

Answer – A
By default, AWS will choose AWS Direct Connect. In order to ensure architecture for proper failover, the AWS Documentation mentions the following points.
To configure the hardware VPN as a backup for your Direct Connect connection:
· Be sure that you use the same virtual private gateway for both Direct Connect and the VPN connection to the VPC.· If you are configuring a Border Gateway Protocol (BGP) VPN, advertise the same prefix for Direct Connect and the VPN.
· If you are configuring a static VPN, add the same static prefixes to the VPN connection that you are announcing with the Direct Connect virtual interface.
· If you are advertising the same routes toward the AWS VPC, the Direct Connect path is always be preferred, regardless of AS path prepending.
Options B, C and D are incorrect because these are not the right configurations when configuring an active/passive connection with AWS Direct Connect and AWS VPN.
For more information on these points, please refer to the below URL
https://aws.amazon.com/premiumsupport/knowledge-center/configure-vpn-backup-dx/