Configuration Restrictions And Guidelines; Performing Mcheck Globally; Performing Mcheck In Interface View; Disabling Inconsistent Pvid Protection - H3C S7500X Series Configuration Manual

Step
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

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

Performing mCheck globally

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

Performing mCheck in interface view

Step
Enter system view.
1.
Enter Layer 2 Ethernet interface or Layer 2
2.
aggregate interface view.
Perform mCheck.
3.

Disabling inconsistent PVID protection

In PVST, if two connected ports use different PVIDs, PVST calculation errors might occur. By default,
inconsistent PVID protection is enabled to avoid PVST calculation errors. If PVID inconsistency is
detected on a port, the system blocks the port.
Command
Command
system-view
stp global mcheck
Command
system-view
interface interface-type interface-number
stp mcheck
39
Remarks
feature is enabled on all ports.