Refer to the exhibit.

In the Cisco ACI environment, when an engineer wants to enforce a specific path for ICMP replies and prevent packets from taking a direct path, setting Layer 2 Unknown Unicast to Hardware Proxy on the bridge domain (BD1) is the appropriate action. This setting ensures that the unknown unicast traffic, which includes ICMP packets destined for an unknown MAC address, is forwarded to the spine proxy. The spine proxy then forwards the packets based on the endpoint table information, ensuring that the packets follow the expected path through the fabric and do not take any shortcuts or direct paths that bypass the intended routing.