Which Destination Address is Used in an ARP Request Frame?
When a device sends an Address Resolution Protocol (ARP) request frame, the destination address is always set to the broadcast MAC address FF:FF:FF:FF:FF:FF.
This is because the requesting device does not yet know the MAC address of the other device it wants to communicate with. By broadcasting its ARP request using this address, all machines on the same subnet can pick up the request and respond if they have the requested IP address.
This is how ARP requests facilitate communication between two devices in a network.
Example:
For example, if device A wants to communicate with device B, it will send an ARP request frame with its own IP address as the source address and FF:FF:FF:FF:FF:FF as the destination address.
All devices on the network will pick up this broadcast, but only device B can respond since it is the only one with the IP address that device A is looking for.
Device B will then send an ARP reply frame back to device A, containing its own MAC address as the source and device A’s MAC address as the destination, thus establishing a connection between them.
