For all of these options first install macchanger.

sudo DEBIAN_FRONTEND=noninteractive apt install macchanger

Random MAC for every NIC

Create a file at /etc/udev/rules.d/81-mac-spoof.rules like so.

ACTION=="add", SUBSYSTEM=="net", RUN+="/usr/bin/macchanger -r $name"

Random MAC for a specific NIC

If the original MAC address of the NIC was dc:a6:32:d0:7b:de then create a file at /etc/udev/rules.d/81-mac-spoof.rules like so.

ACTION=="add", SUBSYSTEM=="net", ATTR{address}=="dc:a6:32:d0:7b:de", RUN+="/usr/bin/macchanger -r $name"

Notes

• https://wiki.archlinux.org/title/MAC_address_spoofing