I have two ISPs at my location. I normally have my Pi-Aware connected to Brightspeed on wlan0 with gateway address 10.11.0.3. Is there a way to automatically switch to the wireless DSL on eth1 with gateway address 10.11.0.5 if the Brightspeed service goes down? Ideally I’d like it to swtich back when Brightspeed comes back up since I cannot remote into it through the wireless DSL.
Maybe using the metric parameters in the Raspberry Pi dhcpcd config file is an option for you ?
https://forums.raspberrypi.com/viewtopic.php?t=304782
With zerotier or tailscale you can manage it over both connections.