A bank uses SQL Server Always On availability groups across three VMs in a subnet and needs a listener IP that receives client requests while the responding replica performs Direct Server Return (DSR) for high throughput. Which Load Balancer configuration is appropriate to implement DSR for the internal Always On listener?

The correct option is to create an Internal Standard Load Balancer with a static private frontend IP, configure a load-balancing rule for the AG listener port, and enable Floating IP (Direct Server Return). SQL Server Always On Availability Groups require a load balancer with DSR (Floating IP) enabled to ensure that client connections to the listener IP are distributed, but responses return directly from the active replica, bypassing the load balancer for improved performance. A Standard Load Balancer supports Floating IP, which is essential for this scenario. Using an Internal Basic Load Balancer is incorrect because Basic Load Balancers do not support Floating IP (DSR). Deploying an Application Gateway is incorrect because it is a Layer 7 load balancer and is not suitable for SQL Server Always On listener traffic, which operates at Layer 4. Assigning the listener IP directly to one VM is incorrect because it defeats the purpose of an availability group listener, which needs a single IP that can float between replicas and be managed by a load balancer for high availability.