A host X, with IP address 200.100.70.10 and a MAC address of A has a packet to send another host Y with IP address 200.100.70.100, but its MAC address is unknown. Fill in the blank to create an ARP request, and an appropriate Ethernet frame:

IP asks ARP to create an ARP broadcast message, filling in sender physical address A , sender IP address , target MAC address .

The resulting ARP packet is passed onto the data link layer, where it gets encapsulated in a link frame using, physical address as a source address, and physical address as the destination address.