A startup firm is looking for a backup & replication solution with AWS. A Pilot Light Architecture will be deployed on an EC2 instance within a VPC which sends a small amount of replication traffic to primary servers deployed at the Data Centre. For this connectivity, the client is planning to use AWS VPN between Data Centre & VGW deployed in this VPC. Before deploying a final solution, the Client IT Team successfully tested replication traffic with a VGW attached to a TEST VPC & CGW at Data Centre. Now the client is planning to move to PRODUCTION VPC as a final solution. Which of the following options will you, as an AWS network consultant, suggest for moving VPN connectivity seamlessly to PRODUCTION VPC with the least changes to the network & in a quick way?

Answer options:

A.Create a new VGW at PRODUCTION VPC& create a new VPN Connection from CGW with a different Tunnel IP address.
B.Detach the VGW from TEST VPC & attach it to PRODUCTION VPC with the same Tunnels IP address.
C.Detach the VGW from TEST VPC & attach it to PRODUCTION VPC with different Tunnels IP addresses.
D.Create a new VGW at PRODUCTION VPC& use the existing VPN Connection from CGW with the same Tunnel IP address.

Correct Answer – B
VPN connection is between VGW & CGW. VPN connection is not associated with a VPC, but it is associated with VGW. So, to move a VPN Connection to a different VPC, VGW can be detached from the existing VPC & attached to another VPC with no changes in Tunnel IP address or any changes in CGW. In the above case, the client can detach VGW from TEST VPC & attach it to PRODUCTION VPC with no changes at CGW.
Option A is incorrect as creating a new VGW & new VPN connection will require to start all configurations from the initial stage which will be time-consuming.
Option C is incorrect as When VGW is detached from one VPC & attached to another VPC, Tunnel IP remains the same & not required to be changed. If there is a change in Tunnel IP, corresponding changes will be required at customer end CGW.
Option D is incorrect as the existing VPN connection will not work with New VGW, for this changes need to be done at CGW.
 For more information on using moving VGW between VPCs, refer to the following URL
 https://www.youtube.com/watch?v=Qep11X1r1QA