Story from best friend's work

[Akasa]

My best friend is a teacher who has a clue when it comes to computers. Her school is loosing their IT person to silicone valley and he's training her on the issues he sees so she can help keep the school running.
The most common error on the network that takes it down? Teachers take the chord coming out of the hub from the input and plug the other end on the output "To keep the cord off the floor."

[Chromatix]

Don't most hubs and switches have protection against precisely this problem? Hubs will usually detect it as "excessive collisions on port" and disable it after a few seconds, while switches will simply not include the looped ports in their spanning tree. (Not sure what they do about broadcasts though. Hmm...)

[Broomjockey]

Somehow, when the input is plugged in to the output, I don't think it'll matter what protections the hub/switch has, you won't be getting an outside signal.