hi at the moment i have a cable modem/router and planning to get a m9 to increase wifi coverage over my 2 floors. The m9 could be used as AP (as i need to connect sonos, tv box and console via LAN) an

I have the s4 with 3 units, i hook up my switch to the main s4 ( thats plugged into the router) and it crashes . plug a single device into it and it works. all i want to do is this, Modem>s4>switch wi