H3C Technologies H3C S5120 Series Switches - Manual (Page 194)

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To do... Use the command... Remarks
Enter Layer 2
Ethernet port view, or
Layer 2 aggregate
port view
interface interface-type
interface-number
Enter port
view or port
group view
Enter port group view
port-group manual
port-group-name
Required
Use either command.
Enable the MSTP feature for the
ports
stp enable
Optional
By default, MSTP is enabled for
all ports after it is enabled for the
device globally.
To control MSTP flexibly, you can use the undo stp enable command to disable the MSTP feature for
certain ports so that they will not take part in spanning tree calculation and thus to save the CPU
resources of the device.
Performing mCheck
MSTP 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 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:
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.
You can perform mCheck on a port through the following two approaches, which lead to the same
result.
Performing mCheck globally
Follow these steps to perform global mCheck:
To do... Use the command... Remarks
Enter system view system-view —
Perform mCheck stp mcheck Required
Performing mCheck in port view
Follow these steps to perform mCheck in port view: