184 CHAPTER 14: MSTP CONFIGURATION[4210-mst-region] active region-configuration# Specify Switch B as the root bridge of spanning tree instance 3.[4210] stp instance 3 root primary3 Configure Switch C.# Enter MST region view.<4210> system-view[4210] stp region-configuration# Configure the MST region.[4210-mst-region] region-name example[4210-mst-region] instance 1 vlan 10[4210-mst-region] instance 3 vlan 30[4210-mst-region] instance 4 vlan 40[4210-mst-region] revision-level 0# Activate the settings of the MST region manually.[4210-mst-region] active region-configuration# Specify Switch C as the root bridge of spanning tree instance 4.[4210] stp instance 4 root primary4 Configure Switch D# Enter MST region view.<4210> system-view[4210] stp region-configuration# Configure the MST region.[4210-mst-region] region-name example[4210-mst-region] instance 1 vlan 10[4210-mst-region] instance 3 vlan 30[4210-mst-region] instance 4 vlan 40[4210-mst-region] revision-level 0# Activate the settings of the MST region manually.[4210-mst-region] active region-configuration