Usage Scenario
If a port of an RSTP/MSTP device is directly connected to an STP device, the port automatically switches to the STP mode and then sends configuration BPDUs to communicate with the remote device. If the STP device is powered off, removed, or is configured to run RSTP/MSTP, the port on the RSTP/MSTP device cannot switch back to the RSTP/MSTP mode. As a result, the RSTP/MSTP device cannot communicate with other RSTP/MSTP devices.
To address this problem, run the
stp mcheck command. After this command is run on a port, the port will automatically switch from the STP mode back to the RSTP/MSTP mode.
Precautions
Running the stp mcheck command in the MSTP process view configures all ports bound to the MSTP process to automatically switch back to the RSTP/MSTP mode.