So here’s a question that really bothered me for the longest time: Why do computers have both physical, MAC addresses and also IP addresses? Adobe acrobat. Why does your computer need two addresses to connect to a network?
Isn’t an IP address sufficient? What is a MAC address anyway?
On a Mac, everything is designed to work just the way you expect it to — from operating it with simple, intuitive gestures to asking Siri to find a file to having your apps automatically update themselves.
This is going to be fun. Keep reading for my enlightening explanation. First let’s talk about MAC addresses because they’re not as famous as their pretentious cousins, IP addresses. Magical Mac Addresses Usually, when someone says Mac they think of the titular computer that elicits cupidity in children and mania in men. Admittedly, the Mac is a thing of beauty but when we hear the term “Mac Addresses” we’re talking about an entirely different beast. A MAC Address, also known as a Physical Address or Burned-in-Address, is just a device identifier.
It’s a long number, 6 bytes to be exact, usually written in base-16 (Hexadecimal) and represents a unique device address for the purposes of communicating with other devices on a network. The device can be anything from a PC or a Printer, a TV or a toaster, an X-box or Xerox copier – if it needs to communicate with other devices it most likely has a MAC address. You can so you should take a look at your own MAc.
The first half of the MAC address identifies the vendor of your network interface and the last half is an arbitrary assignment from that vendor. So in theory, every MAC address in the world is one of a kind. It’s kind of like your unique digital fingerprint. But wait, what about IP addresses? Initially it might seem that IP addresses and MAC addresses are redundant because both are unique identifiers of networked devices. These networked devices are known as hosts and need IP addresses so they can communicate with other hosts. So if IP addresses help hosts communicate with each other why do we need MAC addresses?
I’ll show you but first I’ve got to explain a little bit about TCP/IP. A quick TCP/IP primer TCP/IP is the most prevalent networking protocol stack in existence. Think of TCP as the stuff computers would talk about if they were at a cocktail party or networking event (pun intended).
Just as humans use different languages to communicate ideas and feelings, so computers have their own way of conveying data. The “language” is known as a protocol and defines the rules of communication between computers. Back in the nacient beginnings of the internet it felt like every vendor on earth had their own language for talking with other computers. In the early 80’s, IBM had its thing, Apple had its thing, Xerox had its thing and it was a mess.