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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 8 Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard
Configuring UplinkFast
This example shows how to display the UplinkFast feature settings for all VLANs:
Console> show spantree uplinkfast
Station update rate set to 15 packets/100ms.
uplinkfast all-protocols field set to off.
VLAN port list
------------------------------------------------
1-20 1/1(fwd),1/2-1/5
21-50 1/9(fwd), 1/6-1/8, 1/10-1/12
51-100 2/1(fwd), 2/12
Console>
Disabling UplinkFast
To disable UplinkFast and restore the default spanning tree bridge priority, port cost, and port-VLAN
cost values to their default values, enter the clear spantree uplinkfast command.
Caution
Use caution when entering the clear spantree uplinkfast command. This command restores the
port-VLAN costs on all ports to the default minus one (18) and the port cost to the default value (19). If
you have configured per-VLAN load sharing on redundant trunk links, the load-sharing configuration
can be affected by this command.
You can disable only spanning tree UplinkFast processing on the switch using the set spantree
uplinkfast disable command. This command does not affect the bridge priority, port cost, and
port-VLAN cost values on the switch.
Note
When you disable UplinkFast, it affects all VLANs on the switch. You cannot disable UplinkFast on a
per-VLAN basis.
To disable UplinkFast on a switch, perform this task in privileged mode:
This example shows how to disable UplinkFast on the switch and restore the default bridge priority, port
cost, and port-VLAN cost values:
Console> (enable) clear spantree uplinkfast
This command will cause all portcosts, portvlancosts, and the
bridge priority on all vlans to be set to default.
Do you want to continue (y/n) [n]? y
VLANs 1-1005 bridge priority set to 32768.
The port cost of all bridge ports set to default value.
Task
Command
Step 1
(Optional) Disable UplinkFast processing on the switch and
restore the default bridge priority, port cost, and port-VLAN
cost values.
clear spantree uplinkfast
Step 2
(Optional) Disable UplinkFast processing on the switch
without affecting the bridge priority, port cost, and
port-VLAN cost values.
set spantree uplinkfast disable
Step 3
Verify that UplinkFast is enabled.
show spantree uplinkfast