1-33Configuring the Mode a Port Uses to Recognize/Send MSTP PacketsRefer to Configuring the Mode a Port Uses to Recognize/Send MSTP Packets in the section about rootbridge configuration.Enabling Output of Port State Transition InformationRefer to Enabling the Output of Port State Transition Information in the section about root bridgeconfiguration.Enabling the MSTP FeatureRefer to Enabling the MSTP Feature in the section about root bridge configuration.Performing mCheckMSTP has three working modes: STP compatible mode, RSTP mode, and MSTP mode.If a port on a device running MSTP (or RSTP) connects to a device running STP, this port willautomatically migrate to the STP-compatible mode. However, it will not be able to migrate automaticallyback to the MSTP (or RSTP) mode, but will remain working in the STP-compatible mode under thefollowing circumstances:z The device running STP is shut down or removed.z The device running STP migrates to the MSTP (or RSTP) mode.By then, you can perform an mCheck operation to force the port to migrate to the MSTP (or RSTP)mode.Configuration Prerequisitesz MSTP has been correctly configured on the device.z MSTP is configured to operate in MSTP mode or RSTP-compatible mode.Configuration ProcedureYou can perform mCheck on a port through the following two approaches, which lead to the sameresult.Performing mCheck globallyFollow these steps to perform global mCheck:To do... Use the command... RemarksEnter system view system-view —Perform mCheck stp mcheck RequiredPerforming mCheck in interface viewFollow these steps to perform mCheck in interface view:
