Table of Contents
Advertisement
Chapter 15
Configuring MSTP
Configuring Port Priority
If a loop occurs, the MSTP uses the port priority when selecting an NNI to put into the forwarding state.
You can assign higher priority values (lower numerical values) to NNIs that you want selected first and
lower priority values (higher numerical values) that you want selected last. If all interfaces have the same
priority 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 port priority of an
interface. This procedure is optional.
Command
Step 1
configure terminal
Step 2
interface interface-id
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
Note
The show spanning-tree mst interface interface-id privileged EXEC command displays information
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.
78-17058-01
Purpose
Enter global configuration mode.
Specify an interface to configure, and enter interface
configuration mode.
Valid interfaces include physical NNIs and NNI port
channels. The port-channel range is 1 to 48.
If a physical interface is not an NNI, enter the
Note
port-type nni interface configuration command
before attempting to configure MST port priority.
If the interface is a port channel, all members of the
port channel must be NNIs.
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 15.
•
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.
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
Configuring MSTP Features
15-17
Hide quick links:
Advertisement
Table of Contents
Troubleshooting
