Using usb wifi and onboard wifi simultaneously to connect to internet

Question

I have a raspberry at a very remote site where the wifi range is not that great. I am using a USB wifi with the antenna to connect to the wifi. Should I disable the onboard wifi in this case as I am using external USB wifi.?

Also, is it safe to keep both the interfaces enabled (USB wifi + onboard wifi) on static IP address connected to the same ssid.? Will they create any clash.? I was planning to keep both the interfaces enabled, just in case if one fails for some reason, another interface can keep the things going.?

Thanks

Answer 1

It doesn't matter if both interfaces are activated when then build in isn't configured in /etc/wpa_supplicant/wpa_supplicant.conf. But to avoid possible confusion I would prefer to disable the build in wifi interface with putting this into the /boot/config.txt:

# Disable Pi3 onboard WiFi
dtoverlay=pi3-disable-wifi

To use two interfaces for failover it isn't done to give both an ip address. Wifi will not switch over automatically. You have to reboot. To avoid this you must use bonding. Here is a suggestion to use dynamic failover.

Answer 2

You have 2 options, (1) Disable onboard WiFi or (2) Use networkmanager instead of ifupdown.

(1) is explained already as another answer by @Ingo

(2) You can install networkmanager using apt install networkmanager

You can follow https://askubuntu.com/questions/377687/how-do-i-connect-to-a-wifi-network-using-nmcli to connect to network.

You can follow https://askubuntu.com/questions/947965/how-to-trigger-network-manager-autoconnect to make networkmanager autoconnect.