Host OS MAC address Spoofing

My computers are connecting to and behind a router, after pressing switch button on the computer box to power on the computer, what time the router knows my MAC address? When the computer makes network traffic? At BIOS time, booting time before desktop environment or when? At this time does the customed MAC address using? Sorry I don’t know how to assign the customed MAC address to Ubuntu before making connection to the AP.

It knows as soon as you connect to the network.

Create a systemd service that spoofs the MAC address before connecting.

In my configuration, I have a file called /etc/systemd/system/macspoof.service which contains

Description=Spoofs MAC addresses

ExecStart=/usr/bin/macchanger -e interface


Replace “interface” with the name of your network interface and enable the service.

another thing to take into consideration if you are concerned about mac address fingerprinting is your hostname in your operating system as well. this gets left out of the discussion in a lot of places. randomize the hostname along with the mac for extra precaution, especially if your hostname is unique.

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Open Firefox Browser? Or at BIOS time? How do I identify the when I connect to the network?

it will most likely be when your network-manager icon shows you are connected to the network. do you have your computer set to automatically connect to the network when you plug in an ethernet cable or various wifi hotspots are in range? if so, disable the autoconnections. this should prevent you from connecting to the network before you spoof or change your mac address or hostname. plus, if you go mobile with your computer, it prevents you from having a potentially unique fingerprint that can be sniffed based on the wifi networks your machine is attempting to connect to.

Neither. When whatever is managing your network (e.g. network-manager) connects to wifi or ethernet.

In Ubuntu 18.04 network-manager allows you to random MAC address, next time if automatically connect to the network is enabled, would MAC address change before connecting to the network?

Is MAC address back to manufactory since switch to stanby or wake up?



i am not familiar enough with the latest version of ubuntu because i have not used it. so i cannot answer.

I’d suggest to use a package analyzer such as tshark / wireshark. I wouldn’t be surprised at all to find some bugs which result in the real MAC leaking anyhow.

Networking / MAC address is quite complex. See Tails - MAC address anonymization to get an overview how many moving parts are involved and why it could go wrong.

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The wireless card will first list the hotspots around if the Network Manager is enabled, does only receive the list can make MAC address leaked?

Yes. My previous comment applies.