Load Balancer Configuration Guide

Correct Answer - D.

Option A is incorrect because, in this scenario, Application Load Balancer should be chosen as Network Load Balancer that runs at the network layer and does not support host-based routing.

Option B is incorrect because, with Network Load Balancer, you cannot route the traffic based on the host header.

Option C is incorrect because path-based routing routes requests based on the URL in the requests.

However, the requests need to be routed based on the host header.

Option D is CORRECT because you can define rules in the Application Load Balancer listener by adding host conditions.

Then the requests are forwarded based on the host field of the HTTP header.

Reference:

https://aws.amazon.com/elasticloadbalancing/features/. https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html.

To route requests based on the hostname in the host header to two different target groups, you would need to use an Application Load Balancer or a Network Load Balancer, as the Classic Load Balancer does not support this functionality.

Option A is not a correct solution as Network Load Balancer does not support host-based routing. It only supports IP-based routing.

Option B is also incorrect, as it routes traffic based on the path and not on the hostname in the host header.

Option C is partially correct as an Application Load Balancer can perform path-based routing, but for the given requirement, you need to use host-based routing.

Therefore, the correct answer is option D, which suggests using an Application Load Balancer and configuring host-based routing in the listener rule. Here are the steps to configure this:

1. Create a new Application Load Balancer.
2. Configure the listener to use the HTTP or HTTPS protocol.
3. Create two target groups, one for each set of targets that you want to route traffic to.
4. Configure the listener rule to route traffic based on the hostname in the host header. To do this, you need to:
   • Choose the "Host header" option in the routing configuration.
   • Add the hostnames that you want to route traffic to.
   • Specify the target group that each hostname should route traffic to.

By following these steps, the Application Load Balancer will be able to route requests based on the hostname in the host header to the appropriate target group.