3Com 5500G-EI Command Reference Guide - Page 326

330 CHAPTER 10: USING RSTP COMMANDS Parameter None Description If the network is unstable, even when the bridge running STP on the segment is removed, the corresponding port will still work in the STP compatible mode. Use the stp mcheck command to force the port to work in RSTP mode. If there is any bridge running STP on the segment connected to the current Ethernet port, the port will Switch to run RSTP in STP compatible mode. If the network is rather stable, even when the bridge running STP on the segment is removed, the corresponding port will still work in the STP compatible mode. In this case, you can use this command to force the port to work in RSTP mode. In RSTP mode, when the port receives an STP packet, it will transition to the STP compatible mode. The configuration can only be performed when the bridge runs in RSTP mode. If the bridge is configured to work in STP compatible mode, the command will not make any sense. Related command: stp mode. Example To set the port GigabitEthernet1/0/1 to work in RSTP mode, enter the following: system-view System View: return to User View with Ctrl+Z. [SW5500]interface GigabitEthernet1/0/1 [SW5500-GigabitEthernet1/0/1]stp mcheck stp mode Syntax stp mode { stp | rstp } undo stp mode View System view Parameter stp: Specifies to run Spanning Tree in STP compatible mode. rstp: Specifies to run Spanning Tree in RSTP mode. Description Use the stp mode command to configure Spanning Tree's running mode. Use the undo stp mode command to restore the default Spanning Tree's running mode. By default, the value is rstp.