My father was an IT/ networking master. He died last week and I'm trying to figure out why some of his computers and routers do not have internet. We DO have wifi (although not as fast as usual). I traced all LAN cables down to one huge networking box that has one cable going to the first router. When I unplug this LAN cable the whole house loses all internet including wifi. When I hard wire into this router with a LAN cable coming from 1 of the 4 ports I do not have internet access therefore none of the computers, switches, or other routers that are connected via these LAN cables have internet. But again the wifi works from this router. I didn't know this could even be possible. All internet searches bring up the opposite problem (wired internet but no wifi). Please help me I am not a completely useless person when it comes to this stuff but compared to my dad I felt like.