Basic question for the community (non-tech guy here). I have several devices needing to be connected to my router and/or modem inputs  (eeros, pool device, etc). I am out of space for ethernet inputs on both ATT modem and eeros. Do I need to purchase more Eeros for plug-in capabilities or something else to attach to my ATT modem? Trying to figure out what I need to purchase. Many thanks in advance.