Refer to the exhibit. An application called App_1 is hosted on the server called S1. A silent host application, App_2, is hosted on S2. Both applications use the same VLAN encapsulation. Which…

Setting Unicast Routing to Hardware Proxy primarily influences L3 routing behavior and does not directly facilitate L2 endpoint learning of silent hosts through flooding.

Setting the L2 Unknown Unicast to Flood in the Bridge Domain configuration causes the ACI leaf to flood traffic for unknown destination MAC addresses within that BD. This action will send an ARP request or data frame targeting the silent App_2 to all ports in the BD, including the port where App_2 resides, forcing App_2 to respond and thus be learned by ACI Leaf 2.

Setting L3 Unknown Multicast to Optimized flood pertains to multicast traffic handling and does not address the L2 learning mechanism for a silent unicast host.

Setting Multi-Destination Flooding to Drop would prevent the necessary flooding of unknown unicast, broadcast, and multicast traffic, thereby hindering the learning of a silent host.