AWS Certified Advanced Networking – Specialty ANS-C00 – Question044

A company is about to migrate an application from its on-premises data center to AWS. As part of the planning process, the following requirements involving DNS have been identified.
On-premises systems must be able to resolve the entries in an Amazon Route 53 private hosted zone.
Amazon EC2 instances running in the organization’s VPC must be able to resolve the DNS names of on-premises systems
The organization’s VPC uses the CIDR block 172.16.0.0/16.
Assuming that there is no DNS namespace overlap, how can these requirements be met?

A.
Change the DHCP options set for the VPC to use both the Amazon-provided DNS server and the on-premises DNS systems. Configure the on-premises DNS systems with a stub-zone, delegating the name server 172.16.0.2 as authoritative for the Route 53 private hosted zone.
B. Deploy and configure a set of EC2 instances into the company VPC to act as DNS proxies. Configure the proxies to forward queries for the on-premises domain to the on-premises DNS systems, and forward all other queries to 172.16.0.2. Change the DHCP options set for the VPC to use the new DNS proxies. Configure the on-premises DNS systems with a stub-zone, delegating the name server 172.16.0.2 as authoritative for the Route 53 private hosted zone.
C. Deploy and configure a set of EC2 instances into the company VPC to act as DNS proxies. Configure the proxies to forward queries for the on-premises domain to the on-premises DNS systems, and forward all other queries to the Amazon-provided DNS server (172.16.0.2). Change the DHCP options set for the VPC to use the new DNS proxies. Configure the on-premises DNS systems with a stub-zone, delegating the proxies as authoritative for the Route 53 private hosted zone.
D. Change the DHCP options set for the VPC to use both the on-premises DNS systems. Configure the on-premises DNS systems with a stub-zone, delegating the Route 53 private hosted zone’s name servers as authoritative for the Route 53 private hosted zone.

Correct Answer: C