[c-nsp] BPDU Filtering

[Sergey Velikanov [Intelsoft]]

Hi


Cisco's doc says

"At the global level, you can enable BPDU filtering on Port Fast-enabled interfaces by using the
spanning-tree portfast bpdufilter default global configuration command. This command prevents
interfaces that are in a Port Fast-operational state from sending or receiving BPDUs. The interfaces still
send a few BPDUs at link-up before the switch begins to filter outbound BPDUs. You should globally
enable BPDU filtering on a switch so that hosts connected to these interfaces do not receive BPDUs. If
a BPDU is received on a Port Fast-enabled interface, the interface loses its Port Fast-operational status,
and ____ BPDU filtering is disabled _____."


Could you clarify some moments?

1) Port Fast Enabled, BPDU filtering Enabled:

Port do not send BPDU, but what happen if it receive BPDU?
according to docs, catalyst disable BPDU filter also port lost PortFast status, so port participate in STP election process. Am I right?


2)  Port Fast Disable, BPDU filtering Enabled:
Port do not send BPDU,if port receive BPDU it silent drop this packet,isn't it?