User's Manual

PurposeCommand or Action
(Optional)
Returns the switch priority, diameter, and hello-time to default
values.
switch(config)# no spanning-tree
mst instance-id root
Step 3
This example shows how to configure the switch as the secondary root switch for MSTI 5:
switch# configure terminal
switch(config)# spanning-tree mst 5 root secondary
Configuring the Port Priority
If a loop occurs, MST uses the port priority when selecting an interface to put into the forwarding state. You
can assign lower priority values to interfaces that you want selected first and higher priority values to the
interface that you want selected last. If all interfaces have the same priority value, MST puts the interface
with the lowest interface number in the forwarding state and blocks the other interfaces.
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configure terminal
Step 1
Specifies an interface to configure, and enters interface
configuration mode.
switch(config)# interface {{type
slot/port} | {port-channel
number}}
Step 2
Configures the port priority as follows:switch(config-if)# spanning-tree
mst instance-id port-priority
priority
Step 3
•
For instance-id, you can specify a single MSTI, a range
of MSTIs separated by a hyphen, or a series of MSTIs
separated by a comma. The range is from 1 to 4094.
•
For priority, the range is 0 to 224 in increments of 32.
The default is 128. A lower number indicates a higher
priority.
The priority values are 0, 32, 64, 96, 128, 160, 192, and 224.
The system rejects all other values.
This example shows how to set the MST interface port priority for MSTI 3 on Ethernet port 3/1 to 64:
switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if)# spanning-tree mst 3 port-priority 64
You can only apply this command to a physical Ethernet interface.
Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
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Configuring Multiple Spanning Tree
Configuring the Port Priority