[K12OSN] Excessive collisions cripple network -- Suggestions for solutions?

[Tom Wolfe]

Our Linux labs continue to work great. However, our network has now become 
much bigger, with lots of little satellite switches in our mini labs 
(classes that are serviced by a single Cat 5e wire now have 5-15 K12LTSP 
clients via simple switches).

Every couple of months it seems that accidentally ?someone? plugs both 
ends of an ethernet cable into the same switch. This ends up sending out 
collisions like nuts and slows or cripples our network. I then have to 
figure out where the problem is and fix it.

Are there any recommendations out there on how to prevent these problems 
from affecting my whole network, e.g. is there a switch that will shut 
down a port if it's generating too many collisions or problems? And maybe 
even email me to alert me of the problem??

Suggestions would be appreciated!

Regards,
Tom Wolfe