spanning tree

[glen.grant]

I am trying to get my hands around the difference between bpduguard and bpdu filtering on a interface , we have both enabled on access ports and we continue to have a problem when a person plugs one of these little unmanaged switches or hubs where the hub gets plugged into a main ciscoswitch on 2 different ports and creates a runaway condition in spanning tree and it kills the whole network. When you enable bpduguard and filtering shouldn't this protect the network and shutdown one of the ports ? Also confused about this in cisco's documents about bpdufilter as we have it enabled on all access ports.

Usage Guidelines

Caution Use care when entering the spanning-tree bpdufilter enable command. Enabling BPDU filtering on an interface is approximately equivalent to disabling the spanning tree for this interface. It is possible to create bridging loops if this command is not correctly used.

[glen.grant]

Thanks guys for all your help this is my understanding as well after reading over docs again. Unfortunetly that means we have a "LOT" of fixing to do on dozens of boxes and probably why we keep having these meltdowns because we have both those commands on the interfaces because we have basically turned off bpdu's both xmit and recieve so if someone did plug 2 ports together bpduguard could not work because there are no bpdu's being tranmitted out the user access port . It will probably fix our problem just having the one or the other bpduguard or filter command globally. Thanks again , happy holidays..