My Raspi 4 has a custom metal case, which means the on-board Wifi chip has a hard time getting a reliable signal to my router downstairs. Therefore I want to use an external USB-Wifi adapter and then disable the internal one.

Currently I have three working connections to my router, Eth0, Wlan0 and Wlan1.

Soon I will unplug Eth0 (as I'm only using a cable while I'm setting everything up). which will leave me with the two Wifi connections.

My question is, how can I turn off the built-in Wifi device, without disabling the external Wifi dongle?

The external dongle uses RTL8812AU drivers (github.com/gordboy/rtl8812au.git).

The reasons I want to do this are to keep power consumption down, and also avoid multiple connections to the router because it keeps network routing simpler.

1 Answer 1


I recommend you enable Predictable Network Interface Names (in raspi-config) - this is not essential, but eliminates any possibility of a race condition.

Add denyinterfaces wlan0 to the end of the /etc/dhcpcd.conf file (but above any other added interface lines) which will prevent dhcpcd from attempting to activate the on-board WiFi.

See How to set up networking/WiFi for more detail.

I am not sure if you can just disable the on-board WiFi, but any power saving would be negligible if not activated.

  • Nice. After I turned on Predictable Network Interface Names in raspi-config and rebooted, the device names changed from wlan0 and wlan1, to wlan1 and wn19123fe234a (or some hex garbage like that). I had to use denyinterfaces on both wlan0 and wlan1 to get the desired result. Thanks for the help.
    – Wossname
    Jul 18, 2019 at 13:23
  • The link explains the naming, which is based on MAC, so uniquely identifies the interface.
    – Milliways
    Jul 18, 2019 at 23:39

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