Performing Mcheck; Configuring Digest Snooping - HP A3100-8 v2 SI Configuration Manual

NOTE:
In system view, you can use the stp enable or undo stp enable command to enable or disable STP
•
globally.
You can use the undo stp enable command to disable the MSTP feature for certain ports so that they will
•
not participate 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 that is running MSTP (or RSTP) connects to a device that is running STP, this port
automatically migrates to the STP-compatible mode. However, it will not be able to automatically migrate
back to the MSTP (or RSTP) mode, but will remain working in the STP-compatible mode under the
following circumstances:
The device that is running STP is shut down or removed.
•
The device that is running STP migrates to the MSTP (or RSTP) mode.
•
You can perform an mCheck operation to force the port to migrate to the MSTP (or RSTP) mode.
The following two methods for performing mCheck produce the same results.
Performing mCheck globally
Follow these steps to perform global mCheck:
To do...
Enter system view
Perform mCheck
Performing mCheck in interface view
Follow these steps to perform mCheck in interface view:
To do...
Enter system view
Enter Ethernet interface view or Layer 2
aggregate interface view
Perform mCheck
NOTE:
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, connected devices are in the same region only when their MST region-related
configurations (region name, revision level, VLAN-to-instance mappings) are identical. An MSTP-enabled
device identifies devices in the same MST region by determining the configuration ID in BPDU packets.
The configuration ID includes the region name, revision level, and configuration digest, which is in
16-byte length and is the result calculated via the HMAC-MD5 algorithm based on VLAN-to-instance
mappings.
Use the command...
system-view
stp mcheck
Use the command...
system-view
interface interface-type
interface-number
stp mcheck
73
Remarks
—
Required
Remarks
—
—
Required