NetworkManager MAC spoofing
----------------------------------------------------------------------

* Basic nmcli commands

+ Show connections

  $ nmcli con show

+ Show network devices

  $ nmcli dev status

+ Bring-up interface

  $ nmcli con up <profile> 

+ Bring-down interface

  $ nmcli con down <profile> 

+ Show links

  $ ip link show


* Supported Modes

permanent: use the permanent MAC address of the device.  
preserve:  don’t change the MAC address of the device upon activation.
random:    generate a randomized value upon each connect.
stable:    generate a stable, hashed MAC address.
unset:     this is the default value which allows 

Examples:

+ Change cloned mode

  $ nmcli con modify <WiFi_profile> wifi.cloned-mac-address stable

  $ nmcli con modify <Wired_profile> 802-3-ethernet.cloned-mac-address random

+ Mask-setting to preserve OUI
  
  $ nmcli con modify <profile> \
    802-3-ethernet.genrate-mac-address-mask FF:FF:FF:00:00:00

+ Mask-setting creating a burned-in address. Several OUI can follow.
  
  $ nmcli con modify <profile> \
    802-3-ethernet.generate-mac-address-mask \
    FF:FF:FF:00:00:00 00:50:E4:00:00:00 00:50:E5:00:00:00


More info can be found at:
https://blogs.gnome.org/thaller/2016/08/26/mac-address-spoofing-in-networkmanager-1-4-0/
http://linuxizate.com/nmcli-configuracion-red-nmcli/
https://developer.gnome.org/NetworkManager/stable/settings-802-3-ethernet.html