This property specifies whether or not a multicast MAC address should be used for cluster operations. If this option is enabled, ...

This property specifies whether or not a multicast MAC address should be used for cluster operations. If this option is enabled, Network Load Balancing converts the cluster MAC address belonging to the cluster adapter into a multicast address. It also ensures that the cluster's primary IP address resolves to this multicast address as part of the ARP protocol. At the same time, the adapter can now use its original, built-in MAC address, which, in unicast mode, was disabled.