ARP works between Layers 2 and 3 of the Open Systems Interconnection model (OSI model). The MAC address exists on Layer 2 of the OSI model, the data link layer. The IP address exists on Layer 3, the network layer.

How ARP works in a layer 2 and Layer 3?

For me ARP is a service protocol that glues together layer 2 and layer 3 protocols. It solves the problem that you need to add a layer 2 (MAC) destination address over a shared media like Ethernet or Wireless LAN using IP packets. But ARP is a separate process with separate packets.

How does ARP work in layer 2?

ARP forces all receiving hosts to compare their IP addresses with the IP address of the ARP request. So if host 1 sends another IP packet to host 2, host 1 searches its ARP table for the router 1 MAC address.