HP procurve 8100fl series Management And Configuration Manual page 142

Spanning-Tree Operation
Configuring MSTP
9-26
Syntax: spanning-tree instance < 1..16 > priority <priority-multiplier>
This command sets the priority for the specified port 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:
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 > display.
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 > priority < priority-multiplier >
For example, configuring port gig5/2 with a priority multiplier of
"3" in instance 1, results in this line in the show running output:
interface GigabitEthernet5/2
spanning-tree instance 1 priority 3
(priority-multiplier) x 16