Who knows the IP address of a network participant if they do not know it themselves? A special RARP server does. This server, which responds to RARP requests, can also be a normal computer in the network. However, it must have stored all MAC addresses with their assigned IP addresses. If a network participant sends an RARP request to the network, only these special servers can respond to it.
Since the requesting participant does not know their IP address, the data packet (i.e. the request) must be sent on the lowest layers of the network as a broadcast. This means that the packet is sent to all participants at the same time. However, only the RARP server will respond. If there are several of these servers, the requesting participant will only use the response that is first received. The request-response format has a similar structure to that of the ARP.