I have been in this field a long long time and I saw something today that really baffled me. I have a network of 8 pcs. Using one Windows 7 pc as a server. All of a sudden, none of the 8 pcs (all Windows 7, 64 bit Dell XPS') could NOT talk to each other or the server. But, I can remote into one of the 8 pcs and can get on the net. So it was not the cable modem or the hub. I need to verify the pc I logged into had a fixed IP address but no...the server (Windows 7 pc) had a fixed IP address and it was isolated from everything else but still had access to the internet. The AV on all is Norton Internet Security 2013/14. In my past experience, if there is an attack, Symantec's products shutdown the offending IP address...so this is what I am going on. At other places, I have Symatnec Endpoint Protection blocking attacking pcs for 10 minutes. Becuase all of a sudden, everything started working again. The pcs were already updated with Microsoft Updates...strange things happen on every second Tuesday of the month I swear. What do you think? The hubs are all new, switches are new, cable modem is new. Wiring is in perfect shape.