Prefixes are routed. ARP, in IPv6, is replaced by a function of Neighbor Discovery Protocol (NDP) called Neighbor Advertisment (NA) and Neighbor Solicitation (

Prefixes are routed. ARP, in IPv6, is replaced by a function of Neighbor Discovery Protocol (NDP) called Neighbor Advertisment (NA) and Neighbor Solicitation (NS) where L2 MAC is sent in it's messaging. The NS messaging leverages multicast to communicate with the broader set of hosts for discovery. Basically it sends a message to the multicast address containing the IPv6 address such that it can discover it's MAC. So the flooding/broadcasting for MAC of v4 is replaced by a much more efficient L3 to L2 lookup in v6.