“A multicast address identifies multiple interfaces, and is used for one-to-many communication. With the appropriate multicast routing topology, packets addressed to a multicast address are delivered to all interfaces that are identified by the address.
“IPv6 multicast addresses have the Format Prefix of 1111 1111. An IPv6 address is simple to classify as multicast because it always begins with FF. Multicast addresses cannot be used as source addresses.
“Multicast addresses include additional structure to identify their flags, scope, and multicast group, as shown in the following illustration.”