stp mcheck
Function
The stp mcheck command configures a port to switch from the STP mode back to the RSTP/MSTP/VBST mode.
By default, a port transitions from the STP mode to the RSTP/MSTP/VBST mode by receiving BPDUs. A port that does not receive BPDUs cannot transition from the STP mode to the RSTP/MSTP/VBST mode.
Views
System view, MSTP process view, Ethernet interface view, Eth-Trunk interface view, GE interface view, XGE interface view, MultiGE interface view, 40GE interface view, 100GE interface view, port group view, 25GE interface view
VBST does not support processes. When VBST is running, you cannot run the stp mcheck command in the MSTP process view.
Usage Guidelines
Usage Scenario
If a port of an RSTP/MSTP/VBST switching device is directly connected to an STP switching device, the port automatically switches to the STP mode and then sends BPDUs. This ensures that the two switching devices properly communicate with each other. If the STP switching device is powered off or removed, the port on the RSTP/MSTP/VBST switching device cannot switch back to the RSTP/MSTP/VBST mode. As a result, the RSTP/MSTP/VBST device cannot communicate with other RSTP/MSTP/VBST switching devices.
The stp mcheck command can be used to address this problem. After this command is run on a port, the port will switch from the STP mode back to the RSTP/MSTP mode.
When a VBST-enabled switch connects to an MSTP-enabled switch, the connected port of the MSTP-enabled switch automatically switches to the RSTP mode through negotiation. When the VBST-enabled switch switches to the MSTP mode, the connected ports of the two switches may still work in RSTP mode due to the time sequence problem. You can perform the following operations to manually switch the ports to the MSTP mode.
Prerequisites
If a port in a process with a non-zero ID needs to be configured to switch from the STP mode back to the RSTP/MSTP mode, the port must have been bound to the corresponding process using the stp binding process process-id command.
Precautions
This command does not take effect on a port in Down state.
Running the stp mcheck command in the system view configures all ports on the device to switch back to the RSTP/MSTP/VBST mode.
Running the stp mcheck command in the MSTP process view configures all ports bound to the current MSTP process to switch back to the RSTP/MSTP mode.
Running the stp mcheck command in the interface view configures only the current port to switch back to the RSTP/MSTP/VBST mode.