Some BPDUs can be expected on the network, but it is not ideal for them to flood the network.  Have you looked at the logs on the Cisco switches? They may provide some insight. Are spanning tree priorities manually configured to control which switch is your root switch? Are the interfaces that plug into spanning tree unaware devices set to portfast? Here is a Cisco blog with some further info on some spanning tree features: [URL]
Hi All,   Our File server share freeze so noticed following packets in the capture. Not sure our user computers( Vlan10)  or servers (Vlan80) should see the switch communication?  We also have voip phones.  Client PC Capture: [IMAGE] Server Capture: [IMAGE] As 
RSTP Packets