Leaflet

22
OL-11615-01
To enable BPDU guard on an interface of a system running Cisco IOS, use the spanning-tree
bpduguard command. You must first enable PortFast on the port.
Switch(config)# interface type slot/port
Switch(config-if)# spanning-tree portfast
Switch(config-if)# spanning-tree bpduguard {enable | disable}
This example shows how to enable spanning tree BPDU guard on an interface:
Switch(config)# interface GigabitEthernet2/1
Switch(config-if)# spanning-tree portfast
Switch(config-if)# spanning-tree bpduguard enable
For more information on the spanning-tree bpduguard command on the Catalyst 6500, refer to the
following URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/122sx/cmdref/s1.htm#wp1084894
For more information on the spanning-tree bpduguard command on the Catalyst 4500, refer to the
following URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/12_2_31s/cmdref/snmp
_vtp.htm#wp1065041
BPDU guard can be enabled globally on systems running Cisco IOS by using the spanning-tree portfast
bpduguard default command. When enabled globally, BPDU guard applies to all interfaces that are in
an operational PortFast state.
Switch(config)# spanning-tree portfast bpduguard default
This example shows how to enable BPDU guard globally:
Switch(config)# spanning-tree portfast bpduguard
For more information on the spanning-tree portfast bpduguard default command on the Catalyst
6500, refer to the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/122sx/cmdref/s1.htm#wp1087959
For more information on the spanning-tree portfast bpduguard default command on the Catalyst
4500, refer to the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/12_2_31s/cmdref/snmp
_vtp.htm#wp1076298