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Spanning-Tree Portfast Default Options

On a 3750, if all 3 options are configured - which option has preference? I'm trying to figure out, how the switch will react if a BPDU is received.

spanning-tree portfast bpduguard default

spanning-tree portfast default

spanning-tree portfast bpdufilter default

1 REPLY
Cisco Employee

Re: Spanning-Tree Portfast Default Options

Hello,

Because of the behavior of the BPDU Filter activated at the global level, it will send 10 or 11 BPDUs out of each edge port to see if a BPDU arrives on that port. If it does, the BPDU Filter feature will be deactivated for that port.

As the BPDU Filter on the global level does not actually prevent the switch from receiving and processing BPDUs, the BPDU Guard will take action if a BPDU is received on an edge port and disable it.

Best regards,

Peter

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