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README.md
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README.md

MAC Address

Types of Addresses

  • Physical Address (MAC Address)
  • Logical Address (IP Address)

MAC Address (Media Access Control)

  • A MAC address can also be referred to as :

    • Hardware address
    • Adapter address
    • BIA (Burned-in address)
    • CAM address (Content addressable memory)
    • EHA (Ethernet hardware address)
    • BSSID (Basic service set identifier)

  • A MAC address is a unique hardware identification number, but you can usually change the address in software.

  • It is a hexadecimal number. (The NIC converts this hexadecimal number into binary numbers before processing and using it on the network.)

  • Each network interface connected to your network — whether it’s your router, wireless device, or network card in your computer — has a unique MAC address.

    • (Wi-Fi Router and Access Points have multiple MAC addresses, not just one. They have multiple network interfaces)

  • MAC address is used on data link layer on the network which means that MAC address is visible only on your local LAN or Wi-Fi network. MAC address is not transmitted beyond the first router on your network, so it's not visible to any website you visit.

  • A MAC address consists of six groups of two characters (numbers or letters). These groups are separated by colons(:), hyphens(-), or nothing at all.

  • MAC addresses are available from 00-00-00-00-00-00 through FF-FF-FF-FF-FF-FF.

    • Examples:

      • D4-FB-6A-7C-31-B4
      • d4:fb:6a:7c:31:b4
      • D4FB6A7C31B4

    MAC is not case-sensitive, but it tends to appear either all lower case or all upper case.

  • The first three numbers (i.e. AA:BB:CC) are used to identify a NIC’s manufacturer and are known as an Organizational Unique Identifier (OUI). The OUI is followed by a unique identifier since here too there can be no two devices with the same MAC address.

MAC-address

What MAC addresses are used for?

  • A DHCP server (like your router) uses a MAC address to assign an IP address to a NIC. Without MAC, an adapter can’t get an IP address. Without an IP address, the device can’t connect at all.

    • For example:

      • When a browser on your computer needs to grab a web page from a server on the Internet, for example, that request passes down through several layers of the TCP/IP protocol.

      • The web address you type gets translated to the IP address of the server. Your computer sends the request to your router, which then sends it out onto the Internet.

      • At the hardware level of your network card, though, your network card is only looking at other MAC addresses for interfaces on the same network.

      • It knows to send the request to the MAC address of your router’s network interface.

  • MAC Address Filtering: Networks can use MAC address filtering, only allowing devices with specific MAC addresses to connect to a network. This isn’t a great security tool because people can spoof their MAC addresses.

  • Device Tracking: Because they’re unique, MAC addresses can be used to track you. When you walk around, your smartphone scans for nearby Wi-Fi networks and broadcasts its MAC address. A company named Renew London used trash bins in the city of London to track people’s movements around the city based on their MAC addresses. Apple’s iOS 8 will use a random MAC address each time it scans for nearby Wi-Fi networks to prevent this sort of tracking.

  • Device Identification: Many airport Wi-Fi networks and other public Wi-Fi networks use a device’s MAC address to identify it. For example, an airport Wi-Fi network might offer a free 30 minutes and then ban your MAC address from receiving more Wi-Fi. Change your MAC address and you could get more Wi-Fi. (Free, limited Wi-Fi may also be tracked using browser cookies or an account system.)

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Reasons you might want to change your MAC

For the most part, though, a MAC address is permanent when you don’t do anything. Consequently, if someone knows your device’s MAC (like your phone’s), they can potentially keep track of you — both at local (LAN) and Internet (WAN) levels.

For this reason, by default, modern mobile devices automatically use a temporary random “virtual” (or “private”) MAC address when it connects to a new or public Wi-Fi network.

And that’s also one of the reasons, now and then, you might want to change your device’s MAC.

Take “change” with a loose meaning of the word. It’s more of a spoofing than changing since this is only at the software level. The real MAC will return when you restart or reset the device.

Some reasons:

  • You know your computer has been blocked or restricted from a network and want to sneak through (this is unethical behavior).

  • You’re about to join a new network — like a public Wi-Fi — and don’t want folks to know your device’s real MAC.

How to change the MAC Address :

change the MAC address

To undo this, repeat steps then choose Not Present before clicking OK.


Some computers have two network adapters — one for Wi-Fi and the other for Ethernet, so you will see two MAC addresses in the system configuration.


If two devices are sharing the same MAC address in a network, both devices will get the same IP address, and you’ll have an IP conflict situation, and neither device will get connected.


To find your adapter's physical address : ipconfig /all

Broadcast MAC Address - ff:ff:ff:ff:ff:ff

  • The MAC address used for broadcast is ff:ff:ff:ff:ff:ff.

  • Broadcast is "one to all" type of communication. In other words; "send once receive all".

↗ Sheet for all MAC addresses