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Multiple Instance Spanning-Tree Operation
Configuring MSTP
Syntax: spanning-tree instance < 1..16 >< port-list > priority <priority-multiplier>
This command sets the priority for the specified port(s) in the
specified MST instance. (For a given port, the priority setting
can be different for different MST instances to which the port
may belong.) The priority range for a port in a given MST
instance is 0-255. However, this command specifies the
priority as a multiplier (0 - 15 ) of 16. That is, when you
specify a priority multiplier of 0 - 15, the actual priority
assigned to the switch is:
(priority-multiplier) x 16
For example, if you configure “2” as the priority multiplier on
a given port in an MST instance, then the actual Priority setting
is 32. Thus, after you specify the port priority multiplier in
an instance, the switch displays the actual port priority (and
not the multiplier) in the show spanning-tree instance < 1..16 >
or show spanning-tree < port-list > instance < 1..16 > displays.
You can view the actual multiplier setting for ports in the
specified instance by executing show running and looking for
an entry in this format:
spanning-tree instance < 1..15 > < port-list > priority < priority-
multiplier >
For example, configuring port A2 with a priority multiplier
of “3” in instance 1, results in this line in the show running
output:
spanning-tree instance 1 A2 priority 3