Configuring The Mcheck Variable Of A Port - H3C S9500 Series Operation Manual

Operation Manual – STP
H3C S9500 Series Routing Switches
This configuration takes effect on the CIST and all the MSTIs. The settings of a port
whether to connect the point-to-point link will be applied to all the STIs to which the port
belongs. Note that a temporary loop may be redistributed if you configure a port that is
not physically connected with the point-to-point link as connected to such a link by
force.
By default, the parameter is configured as auto.

1.2.15 Configuring the mCheck Variable of a Port

The port of an MSTP switch operates in either STP-compatible or MSTP mode.
Suppose a port of an MSTP switch on a switching network is connected to an STP
switch, the port will automatically transit to operate in STP-compatible mode. However,
the port stays in STP-compatible mode and cannot automatically transit back to MSTP
mode when the STP switch is removed. In this case, you can perform mCheck
operation to transit the port to MSTP mode by force.
You can use the following measure to perform mCheck operation on a port.
I. Configuration in system view
Perform the following configuration in system view.
Table 1-25 Configure the mCheck variable of a port
Perform mCheck operation on a port.
Note:
By default, MSTP runs in MSTP mode, which is compatible with RSTP and STP
(This mode can recognize MSTP BPDU, STP config BPDU and RSTP config
BPDU). However, the STP switch can only recognize config BPDU (STP BPDU)
sent by the STP and RSTP bridges. After the switch running STP-compatible mode
switches back to MSTP mode, it will not send MSTP BPDU if you do not execute
the stp mcheck command. Therefore, the connected device still sends config
BPDU (STP BPDU) to it, causing the same configuration exists in different regions
and other problems. Remember to perform stp interface mcheck after modifying
stp mode.
II. Configuration in Ethernet port view
Perform the following configuration in Ethernet port view.
Operation
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Chapter 1 MSTP Region-configuration
Command
stp interface interface-list mcheck