Operation Manual – STPH3C S9500 Series Routing Switches Chapter 1 MSTP Region-configuration1-29This configuration takes effect on the CIST and all the MSTIs. The settings of a portwhether to connect the point-to-point link will be applied to all the STIs to which the portbelongs. Note that a temporary loop may be redistributed if you configure a port that isnot physically connected with the point-to-point link as connected to such a link byforce.By default, the parameter is configured as auto.1.2.15 Configuring the mCheck Variable of a PortThe 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 STPswitch, 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 MSTPmode when the STP switch is removed. In this case, you can perform mCheckoperation 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 viewPerform the following configuration in system view.Table 1-25 Configure the mCheck variable of a portOperation CommandPerform mCheck operation on a port. stp interface interface-list mcheckNote: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 configBPDU). However, the STP switch can only recognize config BPDU (STP BPDU)sent by the STP and RSTP bridges. After the switch running STP-compatible modeswitches back to MSTP mode, it will not send MSTP BPDU if you do not executethe stp mcheck command. Therefore, the connected device still sends configBPDU (STP BPDU) to it, causing the same configuration exists in different regionsand other problems. Remember to perform stp interface mcheck after modifyingstp mode.II. Configuration in Ethernet port viewPerform the following configuration in Ethernet port view.
