R211x-HP Flexfabric 11900 Layer 2 - LAN Switching Configuration Guide

Step Command Remarks

4. (Optional.) Enable the

spanning tree feature for the

port.

stp enable

By default, the spanning tree

feature is enabled on all ports.

Performing mCheck

The mCheck feature enables user intervention in the port status transition process.

If a port on a device that is running MSTP or RSTP connects to an STP device, this port automatically

transits to STP mode when the port receives STP BPDUs. However, if the peer STP device is shut down or

removed and the local device cannot detect the change, the local device cannot automatically transit

back to the original mode. To forcibly transit the port to operate in the original mode, you can perform

an mCheck operation.

Suppose a scenario where Device A, Device B, and Device C are connected in sequence. Device A runs

STP, Device B does not run any spanning tree protocol, and Device C runs RSTP or MSTP. In this case,

when Device C receives an STP BPDU transparently transmitted by Device B, the receiving port transits to

the STP mode. If you configure Device B to run RSTP or MSTP with Device C, you must perform mCheck

operations on the ports interconnecting Device B and Device C.

The following methods for performing mCheck produce the same result.

Configuration restrictions and guidelines

When you configure mCheck, follow these restrictions and guidelines:

• The mCheck operation takes effect on devices operating in MSTP or RSTP mode.

• When you enable or disable TRILL on a port, the port might send TCN BPDUs to the peer port,

which causes the peer port to transit to STP mode. When you disable TRILL and enable STP on a port,

HP recommends that you perform mCheck on both the port and the peer port.

Performing mCheck globally

Step Command

1. Enter system view.

system-view

2. Perform mCheck.

stp global mcheck

Performing mCheck in interface view

Step Command

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet or aggregate interface

view.

interface interface-type interface-number

3. Perform mCheck.

stp mcheck