We typically like to have a computer connect to a network other than that of the FlashRouter during a Teamviewer session. This can be a modem, another router, or a smartphone hotspot.
The goal is to setup Internet via WiFi on a router that is NOT your FlashRouter. This way we can wire into the FlashRouter network at the same time to make changes and reboot without getting disconnect from your main WiFi network.
For anyone who is having Internet connection issues through their FlashRouter this aspect of the setup is very important.
My FlashRouter is already flashed and I have Internet...
If you have Internet on the FlashRouter already, but require assistance with your WiFi or VPN setup, you can connect directly to the FlashRouter as you like via wired or WiFi to begin your TeamViewer session.