To configure your network properly, your primary eero must be connected directly to your modem with no other devices in between. If you want to use a switch in addition to your eeros, you can connect a switch to any of your eeros, but it should not be placed between the main eero and your modem. The order should be:
Modem > eero > switch
You can also connect your eeros to each other wirelessly or via a wired Ethernet connection. Additional devices like external hard drives or printers can also be connected to your eeros via Ethernet.
The USB port on your eero is currently only for diagnostic purposes. Please don’t connect anything to your eeros via USB.