Cisco Catalyst 2950 Command Reference Manual page 508

spanning-tree uplinkfast
Do not enable the root guard on interfaces that will be used by the UplinkFast feature. With UplinkFast,
the backup interfaces (in the blocked state) replace the root port in the case of a failure. However, if root
guard is also enabled, all the backup interfaces used by the UplinkFast feature are placed in the
root-inconsistent state (blocked) and prevented from reaching the forwarding state.
If you set the max-update-rate to 0, station-learning frames are not generated, so the spanning-tree
topology converges more slowly after a loss of connectivity.
Examples This example shows how to enable UplinkFast:
Switch(config)# spanning-tree uplinkfast
You can verify your setting by entering the show spanning-tree summary privileged EXEC command.
Related Commands Command
show spanning-tree
spanning-tree stack-port
spanning-tree vlan
Catalyst 2950 and Catalyst 2955 Switch Command Reference
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Description
summary Displays a summary of the spanning-tree port states.
Enables cross-stack UplinkFast (CSUF) on an interface and
accelerates the choice of a new root port when a link or switch
fails or when spanning tree reconfigures itself.
root primary Forces this switch to be the root switch.
Chapter 2 Catalyst 2950 and 2955 Cisco IOS Commands
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