Performing Mcheck; Performing Mcheck Globally; Performing Mcheck In Interface View - HP 5120 EI Series Lan Switching Configuration Manual

Step
3. Enable the spanning tree
feature on specific VLANs.
4. Enter interface view or port
group view.
5. Enable the spanning tree
feature for the port or group of
ports.

Performing mCheck

If a port on a device that is running MSTP, RSTP, or PVST connects to an STP device, this port automatically
transits to the STP mode. However, it cannot automatically transit back to the original mode under the
following circumstances:
The STP device is shut down or removed.
•
The STP device transits to the MSTP, RSTP, or PVST mode.
•
Suppose Device A running STP, Device B with no spanning tree feature enabled, and Device C running
MSTP, RSTP, or PVST are connected in order. Device B will transparently transmit the STP BPDUs, and the
port on Device C and connecting to Device B will transit to the STP mode. After you enable the spanning
tree feature on Device B, to run MSTP, RSTP, or PVST between Device B and Device C, you must perform
an mCheck operation on the ports interconnecting Device B and Device C, in addition to configuring the
spanning tree to operate in MSTP, RSTP, or PVST mode on Device B.
To forcibly transit the port to operate in the original mode, you can perform an mCheck operation.
The following methods for performing mCheck produce the same result.

Performing mCheck globally

Step
1. Enter system view.
2. Perform mCheck.

Performing mCheck in interface view

Step
1. Enter system view.
2. Enter Layer 2 Ethernet interface view or Layer 2
aggregate interface view.
Command
stp vlan vlan-list enable
•
Enter Layer 2 Ethernet interface
view or Layer 2 aggregate
interface view:
interface interface-type
interface-number
•
Enter port group view:
port-group manual
port-group-name
stp enable
88
Remarks
By default, the spanning tree
feature is enabled on VLANs.
Use either command.
Optional.
By default, the spanning tree
feature is enabled on all ports.
Command
system-view
stp mcheck
Command
system-view
interface interface-type interface-number