Reference Guide

spanning-tree mst
Congures an MST instance and determines root and bridge priorities.
Syntax
spanning-tree mst instance number priority | root {primary | secondary}
Parameters
• instance number — Enter an MST instance number (0 to 63).
• 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 congured
Command Mode CONFIGURATION
Usage Information The MST protocol 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
Congures 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
Layer 2 203