Wi-PWN
ESP8266 firmware for performing deauthentication attacks
... clients safely from a wireless network. Because these management packets are unencrypted, you just need the MAC to address of the Wi-Fi router and of the client device which you want to disconnect from the network. You don’t need to be in the network or know the password, it’s enough to be in its range. With the 802.11w-2009 updated standards, management frames are encrypted by default.