(Optional) Configuring a Priority for a Switch in an MSTI
Context
In an MSTI, there can be only one root bridge, which is the logical center of the MSTI. The root bridge should be a high-performance switch; however, the priority of such a device may not be the highest on the network. To ensure that such a device is selected as the root bridge, set a low priority for low-performance switches, and set a high priority for high-performance switches. A smaller priority value indicates a higher priority.
Procedure
- Run system-view
The system view is displayed.
- Run stp process process-id
The MSTP process view is displayed.
- Run stp [ instance instance-id ] priority priority
A priority is set for the switch in an MSTI.
The default priority value of the switch is 32768.
If instance-id is not specified, a priority is set for the switch in MSTI 0.
To configure a switch as the primary root bridge, run the stp [ instance instance-id ] root primary command directly. The priority value of this switch is 0.
To configure a switch as the secondary root bridge, run the stp [ instance instance-id ] root secondary command. The priority value of this switch is 4096.
In an MSTI, a switch cannot act as the primary root bridge and secondary root bridge at the same time.
If the stp [ instance instance-id ] root primary or stp [ instance instance-id ] root secondary command has been executed to configure the device as the root bridge or secondary root bridge, to change the device priority, run the undo stp [ instance instance-id ] root command to disable the root bridge or secondary root bridge function and run the stp [ instance instance-id ] priority priority command to set a priority.