Performing Mcheck; Configuration Prerequisites; Configuration Procedure; Configuration Example - H3C S5120-SI Series Operation Manual

Performing mCheck

Ports on an MSTP-enabled device have 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 will
automatically migrate to the STP-compatible mode. However, it will not be able to migrate automatically
back to the MSTP (or RSTP) mode, but will remain working in the STP-compatible mode under the
following circumstances:
The device running STP is shut down or removed.
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 Prerequisites

MSTP has been correctly configured on the device.
MSTP is configured to operate in MSTP mode or RSTP mode.

Configuration Procedure

You can perform mCheck on a port through two approaches, which lead to the same result.
Performing mCheck globally
Follow these steps to perform global mCheck:
Enter system view
Perform mCheck
Performing mCheck in interface view
Follow these steps to perform mCheck in interface view:
Enter system view
Enter Ethernet interface view, or Layer
2 aggregate interface view
Perform mCheck

Configuration Example

# Perform mCheck on port GigabitEthernet 1/0/1.
1) Method 1: Perform mCheck globally.
<Sysname> system-view
[Sysname] stp mcheck
2) Method 2: Perform mCheck in interface view.
To do...
To do...
Use the command...
system-view
stp mcheck
Use the command...
system-view
interface interface-type
interface-number
stp mcheck
1-32
Remarks
—
Required
Remarks
—
—
Required