I have network based on stupid hubs.
And freebsd router in center of this network.
Today i see in 'systat -vmstat' :
Interrupts 8005 em1:rx 0
That was a loop on one hub.
Is there any way to detect this and email me if this happent?
Either institute sufficient administrative controls to prevent loops from being formed or replace your hubs with switches capable of running spanning tree.