I have been reading through this website for hours but haven't been able to solve my issue. My private network is this: comcast cable/tv/phone modem to which I have connected a linksys wireless router and tv via Ethernet. I have a fire tv device I would like to connect via ethernet- I have already purchased the fire tv Ethernet adapter (fire tv is too slow on wifi). My problem occurs when I plug in the fire tv into the lan port on my linksys wifi router the wifi stops working. The fire tv setup for Ethernet connection asks me to imput router IP, prefix length (whatever that is), gateway, dns1, and dns2. I have setup the fire tv Ethernet via someones help guide but it did not work. Any help would be very appreciated.