Performing Mcheck; Configuring Digest Snooping - HP 5820X series Configuration Manual

To do...
4. Enable the MSTP feature for the
ports
In system view, you can use the stp enable or undo stp enable command to enable or disable STP
globally.
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 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 migrate to
the STP-compatible mode automatically. 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.
Perform mCheck on a port through the following two approaches, which lead to the same result.
Performing mCheck globally
To perform global mCheck:
To do...
1. Enter system view
2. Perform mCheck
Performing mCheck in interface view
To perform mCheck in interface view:
To do...
1. Enter system view
2. Enter Ethernet interface view or Layer
2 aggregate interface view
3. Perform mCheck
An mCheck operation takes effect on a device only when MSTP operates in RSTP or MSTP mode.

Configuring digest snooping

As defined in IEEE 802.1s, interconnected devices are in the same region only when the MST region-
related configurations (region name, revision level, VLAN-to-instance mappings) on them are identical. An
MSTP-enabled device identifies devices in the same MST region by checking the configuration ID in BPDU
Use the command...
stp enable
Use the command...
system-view
stp mcheck
Use the command...
system-view
interface interface-type
interface-number
stp mcheck
83
Remarks
Optional.
By default, MSTP is enabled for
all ports after it is enabled for
the device globally.
Remarks
—
Required
Remarks
—
—
Required