AGW1 is an Application Gateway that has a routing rule (Rule1) sending requests for http://www.contoso.com to backend pool Pool1. Pool1 targets VMSS1. You deployed a new virtual machine scale set VMSS2 and must configure AGW1 so that all requests for http://www.adatum.com go to VMSS2, while requests for http://www.contoso.com continue to reach Pool1. Which three actions should you perform?

To direct requests for a new hostname (http://www.adatum.com) to a new backend (VMSS2) while maintaining existing routing, you need to configure three core Application Gateway components. First, add a backend pool to define VMSS2 as a target for traffic. Second, add a listener to specify that the Application Gateway should listen for incoming requests on http://www.adatum.com. Finally, add a rule to connect the new listener (for http://www.adatum.com) to the new backend pool (containing VMSS2), ensuring requests are routed correctly. Modifying an HTTP setting or adding an HTTP setting would be relevant if you needed to change parameters like port, protocol, or cookie-based affinity for an existing backend pool, but not for routing a new hostname to a new backend.