Configuring Path Cost - Cisco IE 3000 Software Configuration Manual

Configuring MSTP Features
Command
Step 3
spanning-tree mst instance-id port-priority priority
Step 4
end
Step 5 show spanning-tree mst interface interface-id
or
show spanning-tree mst instance-id
Step 6 copy running-config startup-config
The show spanning-tree mst interface interface-id privileged EXEC command displays information
Note
only if the port is in a link-up operative state. Otherwise, you can use the show running-config interface
privileged EXEC command to confirm the configuration.
To return the interface to its default setting, use the no spanning-tree mst instance-id port-priority
interface configuration command.

Configuring Path Cost

The MSTP path cost default value is derived from the media speed of an interface. If a loop occurs, the
MSTP 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, the MSTP puts the interface with the lowest interface number in the
forwarding state and blocks the other interfaces.
Beginning in privileged EXEC mode, follow these steps to configure the MSTP cost of an interface. This
procedure is optional.
Command
Step 1 configure terminal
Step 2 interface interface-id
Cisco IE 3000 Switch Software Configuration Guide
17-20
Purpose
Configure the port priority.
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
4094.
For priority, the range is 0 to 240 in increments of 16.
•
The default is 128. The lower the number, the higher
the priority.
The priority values are 0, 16, 32, 48, 64, 80, 96, 112,
128, 144, 160, 176, 192, 208, 224, and 240. All other
values are rejected.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Purpose
Enter global configuration mode.
Specify an interface to configure, and enter interface
configuration mode. Valid interfaces include physical ports and
port-channel logical interfaces. The port-channel range is 1 to 6.
Chapter 17 Configuring MSTP
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