Cisco Nexus 5000 Series Switch CLI Software Configuration Guide (OL-16597-01, July 2009)

PurposeCommand or Action
•
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 from 1 to
4094.
•
For cost, the range is from 1 to 200000000. The default
value is auto, which is derived from the media speed of
the interface.
This example shows how to set the MST interface port cost on Ethernet 3/1 for MSTI 4:
switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if)# spanning-tree mst 4 cost 17031970
Configuring the Switch Priority
You can configure the switch priority for an MST instance so that it is more likely that the specified switch
is chosen as the root bridge.
Exercise care when using this command. For most situations, we recommend that you enter the
spanning-tree mst root primary and the spanning-tree mst root secondary global configuration
commands to modify the switch priority.
Note
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configure terminal
Step 1
Configures a switch priority as follows:switch(config)#
spanning-tree mst
Step 2
•
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 from 1 to 4094.
instance-id priority
priority-value
• For priority, the range is from 0 to 61440 in increments of
4096; the default is 32768. A lower number indicates that the
switch will most likely be chosen as the root bridge.
Priority values are 0, 4096, 8192, 12288, 16384, 20480, 24576,
28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and
61440. The system rejects all other values.
This example shows how to configure the priority of the bridge to 4096 for MSTI 5:
switch# configure terminal
switch(config)# spanning-tree mst 5 priority 4096
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
192 OL-16597-01
Configuring MST
Configuring the Switch Priority