CLI Reference Guide-R07

Chapter 19 | Spanning Tree Commands
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Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆ This command stops all Bridge Protocol Data Units (BPDUs) from being
transmitted on configured edge ports to save CPU processing time. This
function is designed to work in conjunction with edge ports which should only
connect end stations to the switch, and therefore do not need to process
BPDUs. However, note that if a trunking port connected to another switch or
bridging device is mistakenly configured as an edge port, and BPDU filtering is
enabled on this port, this might cause a loop in the spanning tree.
◆ BPDU filter can only be configured on an interface if the edge port attribute is
not disabled (that is, if edge port is set to enabled or auto with the spanning-
tree edge-port command).
Example
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree edge-port
Console(config-if)#spanning-tree bpdu-filter
Console(config-if)#
Related Commands
spanning-tree edge-port (463)
spanning-tree
bpdu-guard
This command shuts down an edge port (i.e., an interface set for fast forwarding) if
it receives a BPDU. Use the no form without any keywords to disable this feature, or
with a keyword to restore the default settings.
Syntax
spanning-tree bpdu-guard [auto-recovery [interval interval]]
no spanning-tree bpdu-guard [auto-recovery [interval]]
auto-recovery - Automatically re-enables an interface after the specified
interval.
Note: If the auto-recovery option is not set and bpdu guard detects a BPDU the
edge port will be shutdown and must be manually recovered using the command,
no shutdown on the disabled interface. For example if edge port Ethernet 1/3 is
shutdown the following command will restore it:
Console(config)#interface ethernet 1/3
Console(config-if)#no shutdown
Console(config-if)#