Hi All,
Im slightly confused about this feature, my understanding is that if you have a port with portfast enabled and connect a switch downstream, BPDU Guard will actively block the incoming BPDU's and put the port into err-disabled state.
However i was wondering if this feature would also protect the port with BPDU Guard enabled from a Hub being connected downstream?
My initial reaction was to think it would not due to BPDU's being a feature unique to a switch (am i right?) however the wonderfully concise Cisco Press CCNP BCMSN Exam Certification Guide
By David Hucaby, a series which have always been an entertaining and humerous read from start to finish and difficult to put down
, confused the living hell out of me on this one.
It says:-
Use BPDU Guard on all Switch ports where STP Portfast is enabled. This prevents any possibility that a
switch being added to the port, either intentionally or by mistake. BPDU's would not normally be expected there
and would be detected if a switch or hub was inadvertently connected.
Naturally, BPDU gard does not prevent a bridging loop from forming if a hub is connected to the portfast port.
So which is it, this paragraph says switch, then switch or a hub, then not a hub.
