Specifications
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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 12 Configuring STP
Configuring Spanning-Tree Features
Configuring the Switch Priority of a VLAN
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 vlan vlan-id root primary and the spanning-tree vlan vlan-id root secondary global
configuration commands to modify the switch priority.
Beginning in privileged EXEC mode, follow these steps to configure the switch priority of a VLAN:
To return the switch to its default setting, use the no spanning-tree vlan vlan-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 vlan vlan-id root primary and the spanning-tree vlan vlan-id root secondary global
configuration commands to modify the hello time.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
spanning-tree vlan vlan-id priority priority Configure the switch priority of a VLAN.
• For vlan-id, you can specify a single VLAN identified by
VLAN ID number, a range of VLANs separated by a
hyphen, or a series of VLANs separated by a comma. The
range is 1 to 4094 when the EI is installed and 1 to 1005
when the SI is installed.
• 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 4096, 8192, 12288, 16384,
20480, 24576, 28672, 32768, 36864, 40960, 45056,
49152, 53248, 57344, and 61440. All other values are
rejected.
Step 3
end Return to privileged EXEC mode.
Step 4
show spanning-tree vlan vlan-id Verify your entries.
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.