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Catalyst 2960 Switch SoftwareConfiguration Guide
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Chapter15 Configuring STP
Configuring Spanning-Tree Features
Note The show spanning-tree interface interface-id privileged EXEC command displays information only
if the port is in a link-up operative state. Otherwise, y ou can use the show running-config interface
privileged EXEC command to confirm the configuration.
To return to the default setting, use the no spanning-tree [vlan vlan-id] port-priority interface
configuration command. For information on how to configure load shari ng on trunk ports by using
spanning-tree port priorities, see the “Configuring Trunk Ports for Load Sharing” section on page 12-20.
Configuring Path Cost
The spanning-tree path cost default value is derived from the media speed of an interface. If a loop
occurs, spanning tree uses cost when selecting an interface to put in the forwarding state. You can assign
lower cost values to interfaces that you want selected first and higher cost values that you want selected
last. If all interfaces have the same cost value, spanning tree puts the interface with the lowest interface
number in the forwarding state and blocks the other interfa ces.
Step3 spanning-tree port-priority priority Configure the port priority for an interface.
For priority, the range is 0 to 240, in increments of 16; the
default is 128. Valid values are 0, 16, 32, 48, 64, 80, 96,
112, 128, 144, 160, 176, 192, 208, 224, and 240. All other
values are rejected. The lower the number, the higher the
priority.
Step4 spanning-tree vlan vlan-id port-priority priority Configure the port priority for 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.
For priority, the range is 0 to 240, in increments of 16;
the default is 128. Valid values are 0, 16, 32, 48, 64,
80, 96, 112, 128, 144, 160, 176, 192, 208, 224, and
240. All other values are rejected. The lower the
number, the higher the priority.
Step5 end Return to privileged EXEC mode.
Step6 show spanning-tree interface interface-id
or
show spanning-tree vlan vlan-id
Verify your entries.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose