Configuring The Switch Priority - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 17 Configuring MSTP

Configuring the Switch Priority

You can configure the switch priority and make it more likely that the switch will be chosen as the root
switch.
Note Exercise care when using this command. For most situations, we recommend that you use the
spanning-tree mst instance-id root primary and the spanning-tree mst instance-id root secondary
global configuration commands to modify the switch priority.
Beginning in privileged EXEC mode, follow these steps to configure the switch priority. This procedure
is optional.
Command
Step 1 configure terminal
Step 2 spanning-tree mst instance-id priority priority
Step 3
end
Step 4 show spanning-tree mst instance-id
Step 5
copy running-config startup-config
To return the switch to its default setting, use the no spanning-tree mst instance-id priority global
configuration command.
Configuring the Hello Time
You can configure the interval between the generation of configuration messages by the root switch by
changing the hello time.
Note Exercise care when using this command. For most situations, we recommend that you use the
spanning-tree mst instance-id root primary and the spanning-tree mst instance-id root secondary
global configuration commands to modify the hello time.
78-11194-09
Purpose
Enter global configuration mode.
Configure the switch priority for an MST instance.
• For instance-id, you can specify a single instance, a
range of instances separated by a hyphen, or a series of
instances separated by a comma. The range is 0 to 15.
For priority, the range is 0 to 61440 in increments of
•
4096; the default is 32768. The lower the number, the
more likely the switch will be chosen as the root switch.
Valid priority values are 0, 4096, 8192, 12288, 16384,
20480, 24576, 28672, 32768, 36864, 40960, 45056,
49152, 53248, 57344, and 61440. All other values are
rejected.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring MSTP Features
17-19