Which Cisco Catalyst feature automatically disables the port in an operational PortFast upon receipt of a BPDU?
A. BackboneFast B. UplinkFast C. Root Guard D. BPDU Guard E. BPDU Filter
Correct Answer: D
We only enable PortFast feature on access ports (ports connected to end stations). But if someone does not know he can accidentally plug that port to another switch and a loop may occur when BPDUs are being transmitted and received on these ports.
With BPDU Guard, when a PortFast receives a BPDU, it will be shut down to prevent a loop.