multiple interface

I have watchdog working on my raspberry pi using the interface eth0. I have also set a backup wifi connection (IOT device has static local wifi IP set (no DHCP)) incase the ethernet goes down. I can not seem to figure out how to set up the wifi as a backup in watchdog so it only reboots when...

i have 4 Ubuntu 20.04 VMs running on VirtualBox. Each Ubuntu has 4 network adapters which i have added, they are all in bridged connection. My goal with this ideea is to have different networks such as (10.1.1.10/24 or 20.2.2.20/24 ore 30.3.3.30/24) on each interface so that VM(1,2,3,4) has 3...