21-16
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 21 Configuring Optional STP Features
Enabling Loop Guard
This example shows how to enable loop guard:
Router# configure
terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
interface fastEthernet 4/4
Router(config-if)#
spanning-tree guard loop
Router(config-if)#
^Z
This example shows how to verify the configuration:
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 filter is enabled
Loop guard is enabled on the port
BPDU:sent 0, received 0
Router#
Tip
For additional information (including configuration examples and troubleshooting information), see the
documents listed on this page:
http://www.cisco.com/en/US/products/hw/routers/ps368/tsd_products_support_series_home.html
Command
Purpose
Step 1
Router(config)#
interface
{
type
1
slot/port
} |
{
port-channel
port_channel_number
}
1.
type
=
ethernet
,
fastethernet
,
gigabitethernet
, or
tengigabitethernet
Selects a port to configure.
Step 2
Router(config-if)#
spanning-tree guard loop
Configures loop guard.
Step 3
Router(config)#
end
Exits configuration mode.
Step 4
Router#
show spanning-tree interface 4/4 detail
Verifies the configuration impact on that port.