I am intermittently having ports shut down on switches throughout my company. The switches I have are Cisco 3560 catalyst. When I check the port it is in an err-disable state. I can bring the port up by doing the shutdown no shutdown command on the interface. When I check the status on the port to see why it went down the reason listed is bpduguard. Bpduguard is enabled on the port. But my understanding was bpduguard detected bpdu packet. I though bpdu packets only came from devices like switches. The devices that are connected to the ports that go into the err-disable state are computers (Dell 9200). Why would the switch think that the computers are sending out bpdu packets.
Any insight would be most appreciated.