Performing mcheck, Configuration restrictions and guidelines, Configuration procedure – H3C Technologies H3C S5560 Series Switches User Manual
Page 127: Performing mcheck globally, Performing mcheck in interface view
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Step Command
Remarks
4.
Enter Layer 2 Ethernet or
aggregate interface view.
interface interface-type
interface-number
N/A
5.
Enable the spanning tree
feature on 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.
When a port on an MSTP, RSTP, or PVST device connects to an STP device and receives STP BPDUs, the
port automatically transits to the STP mode. However, the port cannot automatically transit back to the
original mode when the following conditions exist:
•
The peer STP device is shut down or removed.
•
The port cannot detect the change.
To forcibly transit the port to operate in the original mode, you can perform an mCheck operation.
For example, 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, PVST, 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, PVST, or MSTP with Device C, you must perform mCheck
operations on the ports interconnecting Device B and Device C.
Configuration restrictions and guidelines
When you configure mCheck, follow these restrictions and guidelines: The mCheck operation takes effect
on devices operating in MSTP, PVST, or RSTP mode.
Configuration procedure
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