[Explained] MAC address

The MAC (Media Access Control) address is an identifier that every network device uses to uniquely identify itself on a network.

It’s made up of a 6 byte hexadecimal number that is burned into every NIC (network interface card).

The MAC address: 00–04–5A-63-A1–66.

00–04–5A — the first 3 bytes identify the manufacturer of the NIC (network interface card).

63-A1–66 — the last 3 bytes are a unique number from the manufacturer that identifies each device on a network.

The MAC address is also referred to as the physical or hardware address.

MAC has a different appearance in operating systems:

• Windows — 00–04–5A-63-A1–66
• Linux/Apple — 00:04:5A:63:A1:66
• Cisco — 0004.5A63.A166

The purpose of the MAC address is so network devices can communicate with each other. It doesn’t matter how far away each device is located — they can still communicate.

If devices talk to each other using the MAC address.

Then, what is the purpose of the an IP address?

The reason why we still use MAC addresses is that public and private IP addresses can periodically change. The IP address can be changed by the network admin or by your SIP.

BUT, the MAC addresses don’t change. They are permanent.

The way TCP/IP works, that a networking device needs both an IP address and a MAC address.

The IP and MAC addresses work together so that devices can talk to each other.

As stated before:

• A MAC address is used to identify a device.
• An IP address is used to locate a device.

For a real example, we can take a village where we find many private houses. In this scenario, the house address corresponds to the IP address, and the owner’s name corresponds to the MAC address.

Summary:

• IP address tells us WHERE a networking device is located.
• A MAC address tells us WHO the device is.