Which protocol uses broadcasting at layer 3?

DHCP uses a packet called a Discover packet. This packet is addressed to 255.255.255.255. Although ARP uses a broadcast, it is a layer 2 broadcast, not a layer 3 broadcast. IGMP is a layer 3 protocol that uses unicast to register members of a multicast group. SNMP is a layer 3 management protocol that uses unicasts for messaging.