You plan to migrate a Classic Load Balancer to an Application Load Balancer or a Network Load Balancer. For the new load balancer listener, you need to define two rules that route requests based on the host name in the host header. Then the traffic will be routed to two different target groups accordingly. How would you configure the new load balancer?

Answer options:

A.Create a Network Load Balancer and select the HTTP protocol in the listener. Configure the host-based routing in the listener.
B.Launch a new Network Load Balancer and choose the TCP protocol in its listener. Route the traffic based on the path.
C.Set up an Application Load Balancer and configure several rules in the listener to perform path-based routing.
D.Use an Application Load Balancer and configure host-based routing in the listener rule.

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.