Cisco Nexus 5000 Series Switch CLI Software Configuration Guide (OL-16597-01, July 2009)

• no spanning-tree bpduguard—Enables BPDU Guard on the interface if it is an operational edge port
and if the spanning-tree port type edge bpduguard default command is configured.
Before You Begin
Ensure that STP is configured.
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configure terminal
Step 1
Specifies the interface to configure, and enters the
interface configuration mode.
switch(config)# interface type
slot/port
Step 2
Enables or disables BPDU Guard for the specified
spanning tree edge interface. By default, BPDU Guard is
disabled on physical Ethernet interfaces.
switch(config-if)# spanning-tree
bpduguard {enable | disable}
Step 3
(Optional)
Disables BPDU Guard on the interface.
switch(config-if)# no spanning-tree
bpduguard
Step 4
Enables BPDU Guard on the interface if it is an
operational edge port and if you enter the
spanning-tree port type edge bpduguard
default command.
Note
This example shows how to explicitly enable BPDU Guard on the Ethernet edge port 1/4:
switch# configure terminal
switch (config)# interface ethernet 1/4
switch(config-if)# spanning-tree bpduguard enable
switch(config-if)# no spanning-tree bpduguard
Enabling BPDU Filtering Globally
You can enable BPDU Filtering globally by default on spanning tree edge ports.
If an edge port with BPDU Filtering enabled receives a BPDU, it loses its operation status and as edge port
and resumes the regular STP transitions. However, this port maintains it configuration as an edge port.
Be careful when using this command: using it incorrectly can cause bridging loops.Caution
When enabled globally, BPDU Filtering is applied only on ports that are operational edge ports. Ports
send a few BPDUs at linkup before they effectively filter outbound BPDUs. If a BPDU is received on an
edge port, it immediately loses its operational edge port status and BPDU Filtering is disabled.
Note
Before You Begin
Ensure that STP is configured.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01 207
About STP Extensions
Enabling BPDU Filtering Globally