To use a random MAC address on Debian 12, you can utilize a few different methods, including temporary changes or setting it to generate random addresses automatically. Here's how you can do it:

Method 1: Temporary Change Using macchanger

1. Install macchanger: Open a terminal and install macchanger using the following command:

   sudo apt update
   sudo apt install macchanger
   

2. Identify Your Network Interface: Find the name of your network interface (e.g., wlan0, eth0) by running:

   ip link
   

3. Bring Down the Interface: Replace wlan0 with your interface name:

   sudo ip link set wlan0 down
   

4. Change the MAC Address: Use macchanger to set a random MAC address:

   sudo macchanger -r wlan0
   

5. Bring Up the Interface:

   sudo ip link set wlan0 up
   

6. Verify the Change:

   ip link show wlan0
   

Method 2: Permanent Random MAC Address on Startup

To have a random MAC address every time you boot, you can modify the Network Manager configuration.

1. Open NetworkManager Configuration: Edit the connection file for your network interface. The path may vary, but you can typically find it in /etc/NetworkManager/system-connections/. You can list the available connections with:

   sudo ls /etc/NetworkManager/system-connections/
   

   Then open the specific connection file using a text editor (replace YourConnection with the actual connection name):

   sudo nano /etc/NetworkManager/system-connections/YourConnection
   

2. Modify the Configuration: Look for the [802-11-wireless] section and add or modify the following lines:

   [connection]
   ...
   ethernet.cloned-mac-address=random
   

   or for Wi-Fi connections:

   [802-11-wireless]
   ...
   802-11-wireless.cloned-mac-address=random
   

3. Save and Exit: Save the file and exit the editor.

4. Restart NetworkManager: Restart the NetworkManager to apply the changes:

   sudo systemctl restart NetworkManager
   

Method 3: Manual Random MAC Address Generation

If you want to generate a random MAC address manually, you can use a simple script or command.

1. Generate a Random MAC Address: You can use the following command to generate a random MAC address:

   printf '02:%x:%x:%x:%x:%x:%x\n' $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256))
   

2. Set the Random MAC Address: Use ip to change the MAC address as shown in Method 1, substituting XX:XX:XX:XX:XX:XX with the output of the above command.

Notes

• Temporary Changes: The MAC address will revert to the original on reboot unless you use the NetworkManager method.
• Network Policies: Be aware that changing your MAC address may violate certain network policies.
• Conflict Avoidance: Ensure that the generated MAC address does not conflict with other devices on your network.

By following these methods, you can effectively use a random MAC address on your Debian 12 system!