From: gladston@br.ibm.com
Date: Thu Apr 07 2005 - 14:01:37 GMT-3
Any help trying to understand this Cisco explanation highly appreciated.
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quoted
Understanding BPDU Filtering
At the global level, you can enable BPDU filtering on Port Fast-enabled ports by using the spanning-tree portfast bpdufilter default global configuration command. This command prevents ports that are in a Port Fast-operational state from sending or receiving BPDUs.
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12225seb/scg/swstpopt.htm#wp1046220
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So does it mean that a port configured with just Portfast (no bpdu filtering) will send BPDUs?
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quoted
If a BPDU is received on a Port Fast-enabled port, the port loses its Port Fast-operational status, and BPDU filtering is disabled.
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Can I understand it as "if a port is configured just with Portfast, if a BPDU is received, nothing is done."
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quoted
At the interface level, you can enable BPDU filtering on any port without also enabling the Port Fast feature by using the spanning-tree bpdufilter enable interface configuration command. This command prevents the port from sending or receiving BPDUs.
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The behaviour of 'interface level' is the same of 'global configuration" on the sense that "If a BPDU is received on a Port Fast-enabled port, the port loses its Port Fast-operational status, and BPDU filtering is disabled."?
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