Hello Eyad
When you have communication between hosts that are not directly connected, you must go through several “hops” from network to network to get there. That’s where IP routing comes in. IP routing, which operates at Layer 3 of the OSI model, allows for end-to-end communication and enables a packet to find its way to the destination based on the destination IP address.
However, ARP is still used in this process. Routing involves finding the very next hop to which the packet should be sent to get to its destination. Once a router determines the next hop IP from its routing table, it needs to encapsulate that IP packet into an Ethernet frame. What destination MAC address will it put there? The MAC address that corresponds to the next-hop IP. If it doesn’t know it already from its ARP table, it will send out an ARP request for that information.
So on a hop by hop basis, ARP is still used. That’s the great thing about the OSI layered model, ARP operates at Layer 2 on a hop by hop basis, while IP works at Layer 3 dealing with end to end communication.
Take a look at this post as well, as it may add some helpful information:
I hope this has been helpful!
Laz