Command:

set spantree uplinkfast

Mode:

Switch> (enable)


Syntax:

set spantree uplinkfast enable [rate station_update_rate] [all-protocols {off | on}]

set spantree uplinkfast disable


Syntax Description:

enable

Keyword that enables a fast switchover.

rate station_update_rate

(Optional) Keyword and variable that specify the number of multicast packets transmitted per 100 ms when an alternate port is chosen after the root port goes down.

all-protocols

(Optional) Keyword that specifies whether the switch generates dummy multicast packets for all protocol groups (IP, IPX, and Group) in a network with switches using protocol filtering.

off

(Optional) Keyword that prevents the switch from generating multicasts for all protocol groups.

on

(Optional) Keyword that causes the switch to generate multicasts for all protocol groups.

disable

Keyword that disables Uplink Fast Switchover.

 


Command Description:

Use the set spantree uplinkfast command to enable and Uplink Fast Switchover to alternate ports when the root port fails. This command applies to a switch, not to a WAN.

The set spantree uplinkfast enable command has the following results:

If you run set spantree uplinkfast enable on a switch that has this feature already enabled, only the station update rate is updated. The rest of the parameters are not modified.

If you run set spantree uplinkfast disable on a switch, the UplinkFast feature is disabled, but the switch priority and port cost values are not reset to the factory defaults. To reset the values to the factory defaults, enter the clear spantree uplinkfast command.

The default station_update_rate value is 15 packets per 100 ms, which is equivalent to a 1 percent load on a 10-Mbps Ethernet port. If you specify this value as 0, the switch does not generate station-update-rate packets.

Use the all-protocols on keywords on switches that have UplinkFast enabled but do not have protocol filtering enabled, and that are connected to upstream switches in the network that have protocol filtering enabled. The all-protocols on keywords cause the switch to generate multicasts for each protocol-filtering group.

On switches with both UplinkFast and protocol filtering enabled, or if no other switches have protocol filtering enabled, you do not need to use the all-protocols on keywords.

 


Example:

This example shows how to enable the spantree UplinkFast feature and specify the number of multicast packets transmitted to 40 packets per 100 ms:

Console>(enable) set spantree uplinkfast enable rate 40

VLANs 1-1005 bridge priority set to 49152.
The port cost and portvlancost of all ports increased to above 3000.
Station update rate set to 40 packets/100ms.
uplinkfast turned on for bridge.
Console> (enable)
 

This example shows how to disable the spantree UplinkFast feature:

console> (enable) set spantree uplinkfast disable

Uplinkfast disabled for switch.
Use clear spantree uplinkfast to return stp parameters to default.
console>(enable) clear spantree uplink
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.
The portvlancost of all bridge ports set to default value.
uplinkfast disabled for bridge.
Console> (enable)
 

This example shows how to enable the all-protocols feature:

Console> (enable) set spantree uplinkfast enable all-protocols on

uplinkfast update packets enabled for all protocols.
uplinkfast already enabled for bridge.
 

This example shows how to disable the all-protocols feature:

Console> (enable) set spantree uplinkfast disable all-protocols off

uplinkfast all-protocols field set to off.
uplinkfast already enabled for bridge.
Console> (enable)

 


Misconceptions:
None

Related Commands:
show spantree

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