If you cannot connect to a certain computer over a network, there might be something wrong with the remote computer or with your Internet connection. Or maybe your router needs a reset. Or your Internet provider could be having a temporarily problem that they’ll surely solve, telling you to please be patient and don’t bother calling. Or maybe it’s the fault of one of the routers, switches, access points, servers, or other network hosts that are in between you and the remote computer. How would you know for sure?