Each network interface card (NIC) has a unique MAC (Media Access Control) address. This applies to all types of network cards, including Ethernet cards and WiFi cards. A MAC address is a six-byte or 12-digit hexadecimal number that is used to uniquely identify a host on a network.
An example of a MAC address is 1F-2E-3D-4C-5B-6A, and it refers to the OSI model layer 2 network protocol. In modern networks, ARP, or Address Resolution Protocol, translates a MAC address into a Layer 3 address, such as an IP address. The MAC address can also be called a physical address. Read my post on how to find out your MAC address if you don’t know it.
All MAC addresses are hardcoded into the network card and can never be changed. However, you can change or spoof the MAC address in the operating system itself using a few simple tricks.
So why would you change your MAC address? There are many reasons for this, mostly related to bypassing any MAC address filter installed on your modem, router, or firewall. Changing the MAC address can help you bypass certain network restrictions by emulating an unlimited MAC address or spoofing a MAC address that is already authorized.
For example, a Wi-Fi network might allow only authorized computers to connect to the network and filter computers based on their MAC address. If you can find a valid MAC address, you can spoof your MAC address and access your Wi-Fi network.
Another example: you have an internet service provider that only allows a certain number of computers to connect to the internet from your home. If you have other computers that need to be connected, you can spoof the MAC address of the authorized computer and connect from another computer.
Change Windows MAC Address
You can easily change the MAC address of your network card in Windows by following these steps.
Step 1: Click “Start” then “Control Panel” then “Network Connections” and right-click the network connection for which you want to change the MAC address and select “Properties”. Typically this will be either a local area network connection or a wireless network connection.
If you are using Windows Vista, Windows 7 or later, you need to go to Control Panel, then to Network and Internet, then to Network and Sharing Center, and then click Manage network connections or Change adapter settings.
Then you can right-click the adapter and select Properties.
Step 2. On the “General” or “Network” tab, click the “Configure” button.
Step 3. Now go to the “Advanced” tab and click the “Locally Managed Address” or “Network Address” property.
The default is None. Go ahead, click the Value radio button and enter a new MAC address. The MAC address is a combination of 6 pairs of numbers and symbols, that is, 40-A2-D9-82-9F-F2. The MAC address must be entered without a dash.
You can go to the command line and type IPCONFIG / ALL to verify that the MAC address has been changed. Restart your computer for the changes to take effect.
This is the easiest way to change your MAC address in Windows. You can also do this through the registry, but this is a much more technical way and probably not required by most people.
Change the OS X MAC address
Changing the MAC address in OS X is definitely not as easy as it is in Windows. First, you have to use Terminal (similar to the command line in Windows) to actually change the MAC address.
Second, you need to manually define the technical name of the adapter before you can change the settings. I’ll explain everything below step by step, but sometimes it gets a little tricky.
First, let’s find out the current MAC address of your Mac. You can do this in one of two ways: through System Preferences or through Terminal. Open System Preferences, click Network, and then click the Advanced button. Be sure to first select the appropriate interface (WiFi, Ethernet, etc.) from the list on the left.
Click on the Hardware tab and you will see that the first line is the MAC address. I thought I could just select “Manual” from the “Configure” dropdown, but that doesn’t allow editing the MAC address.
In Terminal, you can get the MAC address by entering the following command:
ifconfig en0 | grep ether
This will give you the MAC address for the en0 interface. Depending on how many interfaces you have on your computer, you may need to run this command multiple times, adding 1 to the number each time. For example, I ran the following commands until I got to a nonexistent interface.
Now you can simply compare the MAC addresses listed here with the one you saw in System Preferences. In my case, my WiFi MAC is f8: 1e: df: d8: 9d: 8a is the same as en1, so this is the interface that I have to use for the following commands.
Before we change the MAC address, you can use a useful command in Terminal to generate a random MAC address if you need one.
openssl rand -hex 6 | sed ‘s / (. ) / 1: / g; s /.$// â€™
Now that you have a new MAC address, you can change the current one using the following command below. Replace XX with the actual MAC address you want to use.
sudo ifconfig en0 ether xx: xx: xx: xx: xx: xx
To do this, you need to be logged in as an administrator or enable the root account in OS X. By default, root is disabled, and is best left disabled if possible. Just log in as administrator and you should be able to run the command without any problems. However, it will ask for a password before changing the MAC address.
Also, the address will not change if you are still connected to a Wi-Fi network. You need to disconnect from any networks first and then run the command. Surprisingly, disconnecting from a wireless network in OS X is far from intuitive. You need to press and hold the Option key and then click the Wi-Fi icon to see the disable option.
So here is a rundown of all the commands I followed to get the current MAC address, generate a random one, update the MAC address, and then check if it actually changed.
As I mentioned earlier, this is definitely not as easy as it is on Windows, but you should be able to do it simply by copying and pasting the commands above. If you have any questions, do not hesitate to leave comments. Enjoy!