Reference Guide

● priority priority value — Set a bridge priority value in increments of 4096 (0 to 61440).
Valid priority values are: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960,
45056, 49152, 53248, 57344, and 61440. All other values are rejected.
● root — Enter a primary or secondary root.
● primary — Enter a device as a primary root.
● secondary — Enter a device as a secondary root.
Default Not configured
Command Mode CONFIGURATION
Usage
Information
The MSTP determines the root bridge but you can assign one bridge a lower priority to increase the
probability it being the root bridge. A lower priority-value increases the probability of the bridge
becoming a root bridge. The no version of this command resets the value to the default.
Example
OS10(config)# spanning-tree mst 0 priority 0
OS10(config)# spanning-tree mst 2 root primary
Supported
Releases
10.2.0E or later
spanning-tree msti
Configures the MSTI, cost, and priority values for an interface.
Syntax
spanning-tree msti instance {cost cost | priority value}
Parameters
● msti instance — Enter the MST instance number (0 to 63).
● cost cost — (Optional) Enter a port cost value (1 to 200000000). Default values:
○ 100 Mb/s Ethernet interface = 200000
○ 1-Gigabit Ethernet interface = 20000
○ 10-Gigabit Ethernet interface = 2000
○ Port-channel interface with one 100 Mb/s Ethernet = 200000
○ Port-channel interface with one 1 Gigabit Ethernet = 20000
○ Port-channel interface with one 10 Gigabit Ethernet = 2000
○ Port-channel with two 1 Gigabit Ethernet = 18000
○ Port-channel with two 10 Gigabit Ethernet = 1800
○ Port-channel with two 100 Mbps Ethernet = 180000
● priority value — Enter a value in increments of 16 as the priority (0 to 240, default 128) .
Default Priority value is 128
Command Mode INTERFACE
Usage
Information
The cost is a value based on the interface type. The greater the cost value, the less likely the port is
selected to be a forwarding port. The priority influences the likelihood that a port is selected to be a
forwarding port if several ports have the same cost.
Example
OS10(conf-if-eth1/1/1)# spanning-tree msti 1 priority 0
OS10(conf-if-eth1/1/1)# spanning-tree msti 1 cost 3
Supported
Releases
10.2.0E or later
spanning-tree mst configuration
Enters MST mode to configure MSTP from Configuration mode.
Syntax
spanning-tree mst configuration
Parameters None
Layer 2 207