CCIE: Root Guard, BPDU Guard, BPDU Filter, and Loop Guard
The BPDU guard feature can be globally enabled on the switch or can be enabled per port, but the feature operates with some differences. At the global level, you enable BPDU guard on Port Fast-enabled ports by using the spanning-tree portfast bpduguard default global configuration command. Spanning tree shuts down ports that are in a Port Fast-operational state if any BPDU is received on them. In a valid configuration, Port Fast-enabled ports do not receive BPDUs. Receiving a BPDU on a Port…