TIP: ARP may sound similar to a Network Address Translation (NAT), but you need to understand that NAT is used for addressing and locating networks whereas, ARP is used to deliver the actual data to the physical device. Once the request reaches the correct network using the IP address, ARP is what converts an IP address to a MAC address and delivers the data packet to the right computer. The IP address is what is first used to find the right network. So, the router sends a broadcast that says “hey everyone, if you have IP address X, please tell me what your MAC address is.” One of your computers will respond “Hello, I have IP address X and my MAC address is XYZ, please forward the data to my MAC address.”

Your router is basically trying to resolve (find) the physical address of which computer this IP address belongs to.

So, the router sends an ARP broadcast request on the LAN. When you router wants to send data packets to your computer with IP address ‘X’, the router needs to know what your computers MAC address is. If your computer has two Ethernet ports and dual-band wireless, it will have four MAC addresses. If it has dual-band wireless capability, it will have a MAC address for each wireless band. If the computer has two Ethernet ports, it will have a MAC address for each Ethernet port. Each network controller has its own MAC address. In the previous image, I have one Etherent controller, and one wireless controller.

What is network mac address