2-727
Catalyst 6500 Series Switch Command Reference—Release8.4
OL-6244-01
Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands set spantree uplinkfast
set spantree uplinkfast
To enable fast switchover to alternate ports when the root port fails, use the set spantree uplinkfast
command. This command applies to a switch, not to a WAN.
set spantree uplinkfast {enable | disable} [rate station_update_rate] [all-protocols {off | on}]
Syntax Description
Defaults The default station_update_rate is 15 packets per 100 milliseconds.
Command Types Switch command.
Command Modes Privileged.
Usage Guidelines This command is not supported by the NAM.
This command is not available in MST mode.
The set spantree uplinkfast enable command has the following results:
•Changes the bridge priority to 49152 for all VLANs (allowed VLANs).
•Increases the path cost and portvlancost of all ports to a value grea ter tha n 3000 .
•On detecting the failure of a root port, an instant cutover occurs to an alternate port selected by
Spanning Tree Protocol.
If you run the set spantree uplinkfast enable command on a switch that has this feature already enabled,
only the station update rate is updated. The rest of th e pa rame ter s a re n ot m odi fied.
If you run the set spantree uplinkfast disable command on a switch, the UplinkFast feature is disabl ed
but the switch priority and port cost values are not reset to the default settings. To reset the values to the
default settings, enter the clear spantree uplinkfast command.
The default station_update_rate value is 15 packets per 100 milliseconds, which is equivalent to a
1-percent load on a 10-megabit per second Ethernet network. If yo u speci fy t his value as 0, t he
generation of these packets is turned off.
enable Enables fast switchover.
disable Disables fast switchover.
rate
station_update_rate (Optional) Specifies the number of multicast packets transmitted per 100 ms
when an alternate port is chosen after the root port goes down.
all-protocols (Optional) Specifies whether or not to generate multicast packets for all
protocols (IP, IPX, AppleTalk, and Layer2 packets).
off (Optional) Turns off the all-protocols feature.
on (Optional) Turns on the all-protocols feature.