What is a MAC Address? Full Form & How to Find It

What is a MAC Address?

A MAC address is a unique identifier assigned to a NIC (Network Interface Controller/Card). It is a 48-bit (or 64-bit) address, tied to the network adapter and usually written in hexadecimal. The full form of MAC address is Media Access Control address.

Why Use MAC Address?

A MAC address is a unique number used to track a device on a network. It provides a secure way to identify senders or receivers and prevent unwanted access. MAC addresses are also used on public Wi-Fi, such as at an airport, to identify a specific device.

Architecture of MAC

The figure below shows the architecture of a MAC address:

The MAC Address example above shows that the structure contains:

• A MAC address made up of 6 octets (groups of eight bits).
• The first three octets, which form the Organizationally Unique Identifier (OUI), a 24-bit number identifying the manufacturer or vendor.
• The last three octets, which are specific to the device (the NIC-specific portion).
• Each octet made up of 8 bits, for example a0 through a7.
• Bit a0 (the least-significant bit of the first octet), which sets the transmission type: 0 for unicast (single destination), 1 for multicast.
• Bit a1, which sets administration: 0 for a globally unique, OUI-enforced address, and 1 for a locally administered address.

Types of MAC Addresses

The two types of MAC addresses are:

Universally Administered Address

UAA is the most widely used type. It is given to the network adapter during manufacturing. The first three octets identify the organization or manufacturer that issued the identifier, and the remaining octets are assigned by that manufacturer.

Locally Administered Address

LAA is an address that changes the adapter’s MAC. A network administrator may assign it to a device, overriding the manufacturer’s address. An LAA does not contain an OUI (Organizationally Unique Identifier). The full form of LAA is Locally Administered Address.

How to find MAC address in Windows?

Below is a step-by-step process to find a MAC address in Windows, using two methods:

Finding the MAC address with the Command Prompt

Step 1) Click on the “Start” button.

Step 2) Type “command prompt” in the search box.

Step 3) In the Command Prompt, type ipconfig /all and press Enter.

Step 4) The command output is displayed.

Scroll down to the value next to “Physical Address”; this value is your MAC address.

Finding MAC address from Network Connection Settings

Another way is to check your network adapter details in Windows.

Step 1) Click on the “Start” button.

Step 2) Type “view network status and tasks” in the search box.

Step 3) Click on your active network connection.

Step 4) In the next screen, click on “Details”.

Step 5) Locate the “Physical Address” entry.

The value shown for the physical address is your MAC address. These steps cover Windows; for other systems, see the guide to finding and changing a MAC address on macOS and Linux.

How To Change The MAC Address in Windows

You can also change, or spoof, the MAC address Windows presents, using Device Manager or the Registry:

Using the Device Manager to change MAC address

Step 1) Click on the “Start” button.

Step 2) Type “device manager” in the search box.

Step 3) Click on “Network Adapters” to expand the tree.

Step 4) Right-click the network adapter and click on “Properties”.

Step 5) In the next screen, click on the “Advanced” tab.

Step 6) Under “Property”, select “Network Address”.

Step 7) In the “Value” field, type the MAC address you want.

Step 8) Restart your PC to enable the change.

Step 9) Verify by typing ipconfig/all in the Command Prompt.

Using Registry to change MAC address

Step 1) Click on the “Start” button.

Step 2) Type “run” in the search box.

Step 3) Type REGEDIT and press “OK”.

Step 4) Navigate to this registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<network adapter>\Parameters

Step 5) Right-click and choose “New” -> “String Value”.

Step 6) Name the value “NetworkAddress” and press Enter.

Step 7) Double-click the new value and enter the adapter’s new MAC value.

Step 8) Press “OK” to save the new value.

Step 9) Restart your PC to enable the changes.

Step 10) Verify by typing ipconfig/all in the Command Prompt.

Difference between MAC address and IP address

The following table shows key differences between a MAC address and an IP address:

FAQs