What Is A MAC Address And Why You Should Know About It?

Lakshan Mamalgaha
4 min readSep 19, 2019

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You have definitely heard about the MAC address and you must know what is it?. Whether you use wireless or wired network at your home or office you are not only need the network software but also the hardware ( such as routers, cables etc) transmit data from your device or computer to your ISP and vice versa from thousands of miles away from you.

And when transmitting data have to ensure the data reaches only you without being altered or overheard. This is handled by the network address. All the data comes down to the network addresses, more commonly known as a Media Access Control (MAC) address. In Computer Network various types of address are introduced; each works at different layer. Media Access Control Address (MAC) is a physical address which works at Data Link Layer. Both IP addresses and MAC addresses are unique identifiers, and together they make data transmission successful. Now let’s see further information on MAC address.

Media Access Control (MAC) Address

A MAC address is a 48-bits hardware identification number that uniquely identifies each device on a network. This is embedded into every network card (known as Network Interface Card) during the time of manufacturing, such as an Ethernet card or Wi-Fi card, and therefore cannot be changed. MAC Address is also known as Physical Address of a network device. For communications within a network segment, it is used as a network address for most IEEE 802 network technologies, including Ethernet, Wi-Fi, and Bluetooth. MAC Address is word wide unique, since millions of network devices exists and we need to uniquely identify each.

Typically MAC addresses are used only to transmit packets from one device to the next as data travels on a network.

That means that your computer’s network adapter’s MAC address travels the network only until the next device along the way. If you have a router, then your machine’s MAC address will go no further than that. The MAC address of your router’s internet connection will show up in packets sent further upstream, until that too is replaced by the MAC address of the next device — likely either your modem or your ISP’s router.

Even if someone knows your device MAC address, that knowledge certainly doesn’t help them do anything either good or bad.

MAC Address vs. IP Address

Both MAC addresses and IP addresses are used by a TCP/IP networks for different purposes. IP addresses are assigned as part of connecting to a network, and MAC addresses are assigned at the time hardware is manufactured.

All devices on the same network have unique MAC addresses. Therefore MAC addresses can be easily used when diagnosing network issues, such as problems with IP addresses. The reason is MAC addresses never change, as opposed to a dynamic IP address, which can change from time to time. Therefore MAC address make a more reliable way to identify senders and receivers of data on the network when diagnosing network issues.

Key Differences Between MAC Address and IP Address

  1. MAC address uniquely identifies each device on a network whereas IP address identifies a connection to a device in a network.
  2. MAC address is 48 bits (6 bytes) hexadecimal address and IP address has two versions, IPv4 a 32-bit address and IPv6 a 128-bit address.
  3. MAC address embedded into device by the manufacturer of interface hardware whereas IP address is assigned by the network administrator or Internet Service Provider (ISP).
  4. Something called the ARP (Address Resolution Protocol) translates an IP address into a MAC address. The ARP is like a passport that takes data from an IP address through an actual piece of computer hardware

MAC addresses and staying safe

When it comes to staying safe, MAC addresses aren’t part of the discussion, because they never travel beyond your local network, and they can’t be hidden, as they’re required for networking to work. Many network adapters allow you to override the MAC address, but even so, it still identifies your computer on the local network.

IP addresses are also required for networking to work. The network has to know which computer to send data to. You can, in many cases, use things like anonymization services and the like to appear to be coming from a different IP address, but that doesn’t change the fact that your machine is still reachable by some IP address.

How to find MAC address

All most all the network devices consists with a MAC address. You can see your network adapter’s MAC addresses by using the command prompt in Windows with the ipconfig /all command. It looks something like this

In Unix/Linux you can use the following commands

Command for UNIX/Linux -  ifconfig -a
ip link list
ip address show

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