A global airlines company uses hybrid connectivity for application servers deployed in high availability mode in both on-premises & VPC. They have created VPC A & VPC B spread across three Availability Zones for deploying multiple servers. The airlines IT team is planning to set up a new DNS server at on-premises locations. Servers in both VPC A & VPC B will need to forward queries to new DNS servers. IT Head is looking to implement a least complex solution which can be implemented with ease. As AWS consultants, they are looking for your guidance to implement this solution with the least management overhead & low cost.
Which of the following solutions can be deployed to meet this requirement?

Answer options:

A.Configure Route 53 Resolver with an outbound endpoint in VPC A & forwarding rules shared with VPC
B.B.Configure Route 53 Resolver with an inbound endpoint in VPC A & forwarding rules shared with VPC
B.C.Configure Distributed forwarders on each instance within VPN A & VPC B which would forward queries to on-premises DNS servers.
D.Configure Zonal forwarders on multiple instances within VPN A & VPC B which would forward queries to on-premises DNS servers.

Correct Answer – A
Route 53 Resolver can be set up easily with low cost to forward DNS queries between on-premises & VPC. In the above case, since DNS servers at on-premises locations need to be used for servers deployed in VPC, a Route 53 Resolver outbound endpoint needs to be set up with forwarding rules. This outbound endpoint is not required to be created for each VPC, but a single endpoint can be shared between multiple VPCs. There is no management overhead with this outbound endpoint, as once it`s set up, you just need to manage forwarding rules.
Option B is incorrect as Inbound endpoints can be used to forward queries from on-premises into VPC.Option C is incorrect as configuring DNS forwarders on all instances will require additional admin work.
Option D is incorrect as implementing Zonal Forwarders is complex & will incur a higher cost than Router 53 Resolver Outbound endpoint.
For more information on using AWS Route 53 Resolver, refer to the following URL
https://d1.awsstatic.com/whitepapers/hybrid-cloud-dns-options-for-vpc.pdf