21-10
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 21 Configuring Optional STP Features
Enabling PortFast BPDU Filtering
Name Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
VLAN0001 0 0 0 1 1
VLAN0010 0 0 0 2 2
---------------------- -------- --------- -------- ---------- ----------
2 vlans 0 0 0 3 3
Router#
Router#
show spanning-tree interface fastEthernet 4/4 detail
Port 196 (FastEthernet4/4) of VLAN0010 is forwarding
Port path cost 1000, Port priority 160, Port Identifier 160.196.
Designated root has priority 32768, address 00d0.00b8.140a
Designated bridge has priority 32768, address 00d0.00b8.140a
Designated port id is 160.196, designated path cost 0
Timers:message age 0, forward delay 0, hold 0
Number of transitions to forwarding state:1
The port is in the portfast mode by default
Link type is point-to-point by default
BPDU:sent 10, received 0
Router(config-if)#
spanning-tree portfast trunk
%Warning:portfast should only be enabled on ports connected to a single
host. Connecting hubs, concentrators, switches, bridges, etc... to this
interface when portfast is enabled, can cause temporary bridging loops.
Use with CAUTION
Router(config-if)#
^Z
Router#
show spanning-tree interface fastEthernet 4/4 detail
Port 196 (FastEthernet4/4) of VLAN0010 is forwarding
Port path cost 1000, Port priority 160, Port Identifier 160.196.
Designated root has priority 32768, address 00d0.00b8.140a
Designated bridge has priority 32768, address 00d0.00b8.140a
Designated port id is 160.196, designated path cost 0
Timers:message age 0, forward delay 0, hold 0
Number of transitions to forwarding state:1
The port is in the portfast mode by portfast trunk configuration
Link type is point-to-point by default
BPDU:sent 30, received 0
Router#
Enabling PortFast BPDU Filtering
These sections describe how to configure PortFast BPDU filtering.
To enable PortFast BPDU filtering globally, perform this task:
BPDU filtering is set to default on each port. This example shows how to enable PortFast BPDU filtering
on the port and verify the configuration in PVST+ mode:
Command
Purpose
Step 1
Router(config)#
spanning-tree portfast
bpdufilter default
Enables BPDU filtering globally on the router.
Step 2
Router#
show spanning-tree summary totals
Verifies the configuration.