Q & A on Which Hosts Respond to an ARP Request? Q: When a arp request coming, does the procedure reply anyway or only when the target address is matched? The former is introduced in Douglas E.Comer and David L.Stevens, Internetworking with TCP/IP volume 2, why? A: The implementation in volume 2 follows the ARP protocol standard. In essence, ARP used when a computer, X, wants to find the hardware address of another computer, Y, on the same network. X broadcasts an ARP Request to which Y responds. Although all computers on the network receive the request, they do not respond because X is not trying to communicate with them.