AWS Certified SysOps Administrator – Associate — Question 261

A company is trying to connect two applications. One application runs in an on-premises data center that has a hostname of host1.onprem private. The other application runs on an Amazon EC2 instance that has a hostname of host1.awscloud private. An AWS Site-to-Site VPN connection is in place between the on-premises network and AWS.

The application that runs in the data center tries to connect to the application that runs on the EC2 instance, but DNS resolution fails. A SysOps administrator must implement DNS resolution between on-premises and AWS resources.

Which solution allows the on-premises application to resolve the EC2 instance hostname?

Answer options

• A. Set up an Amazon Route 53 inbound resolver endpoint with a forwarding rule for the onprem.private hosted zone. Associate the resolver with the VPC of the EC2 instance. Configure the on-premises DNS resolver to forward onprem.private DNS queries to the inbound resolver endpoint.
• B. Set up an Amazon Route 53 inbound resolver endpoint. Associate the resolver with the VPC of the EC2 instance. Configure the on-premises DNS resolver to forward awscloud.private DNS queries to the inbound resolver endpoint.
• C. Set up an Amazon Route 53 outbound resolver endpoint with a forwarding rule for the onprem.private hosted zone. Associate the resolver with the AWS Region of the EC2 instance. Configure the on-premises DNS resolver to forward onprem.private DNS queries to the outbound resolver endpoint.
• D. Set up an Amazon Route 53 outbound resolver endpoint. Associate the resolver with the AWS Region of the EC2 instance. Configure the on-premises DNS resolver to forward awscloud.private DNS queries to the outbound resolver endpoint.

Correct answer: B

Explanation

Option B is correct because it establishes an inbound resolver for the EC2 instance's VPC and configures the on-premises DNS resolver to forward the appropriate DNS queries. The other options either set up forwarding for the wrong hosted zone or use outbound resolvers, which are not suitable for resolving on-premises DNS queries to AWS resources.