3Com 5500G-EI Command Reference Guide - Page 322

326 CHAPTER 10: USING RSTP COMMANDS for the device and ports. This command enables/disables RSTP on a device in system view and enables/disables RSTP on a port in Ethernet Port View. Related command: stp mode. Example To enable RSTP on a Switch, enter the following: system-view System View: return to User View with Ctrl+Z. [SW5500]stp enable To disable RSTP on GigabitEthernet1/0/1, enter the following: [SW5500]interface GigabitEthernet1/0/1 [SW5500-GigabitEthernet1/0/1]stp disable stp bpdu-protection Syntax stp bpdu-protection undo stp bpdu-protection View System view Parameter None Description Use the stp bpdu-protection command to enable BPDU protection on a Switch. Use the undo stp bpdu-protection command to resume the default status of BPDU protection function. By default, BPDU protection is not enabled. For an access layer device, its ports are generally directly connected to a user terminal (such as a PC) or file server, and configured as an edge port to implement fast transition. When such a port receives BPDU packets, the system will set it to a non-edge port and recalculate the spanning tree, which will cause network topology flapping. In normal circumstances, these ports should not receive any BPDU packets. However, someone may forge BPDU to maliciously attack the Switch and cause network flapping. RSTP provides the BPDU protection function against such an attack. After the BPDU protection function is enabled on a Switch, the system will disable an edge port that has received BPDUs and notify the network manager about it. The disabled port can only be re-enabled by the network manager. Example To enable BPDU protection function on a Switch, enter the following: system-view System View: return to User View with Ctrl+Z.