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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 10 Configuring STP
Configuring Advanced STP Features
Configuring Cross-Stack UplinkFast
Before enabling CSUF, make sure your stack switches are properly connected. For more information,
see the
“Connecting the Stack Ports” section on page 10-16
.
Beginning in privileged EXEC mode, follow these steps to enable CSUF:
To disable CSUF on an interface, use the no spanning-tree stack-port interface configuration
command. To disable UplinkFast on the switch and all its VLANs, use the no spanning-tree uplinkfast
global configuration command.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
spanning-tree uplinkfast [max-update-rate
pkts-per-second]
Enable UplinkFast on the switch.
(Optional) For max-update-rate pkts-per-second, specify the
number of packets per second at which update packets are sent. The
range is 0 to 65535; the default is 150 packets per second.
Step 1
interface interface-id
Enter interface configuration mode, and specify the GBIC interface
on which to enable CSUF.
Step 2
spanning-tree stack-port
Enable CSUF on only one stack-port GBIC interface.
The stack port connects to the GigaStack GBIC multidrop
backbone. If you try to enable CSUF on a Fast Ethernet or a
Gigabit-capable Ethernet port, you receive an error message.
If CSUF is already enabled on an interface and you try to enable it
on another interface, you receive an error message. You must
disable CSUF on the first interface before enabling it on a new
interface.
Use this command only on access switches.
Step 3
end
Return to privileged EXEC mode.
Step 4
show spanning-tree
Verify your entries.
Step 5
copy running-config startup-config
(Optional) Save your entries in the configuration file.
