Enabling BPDU guard

For access layer devices, the access ports can directly connect to the user terminals (such as PCs) or file servers. The access ports are configured as edge ports to allow rapid transition. When these ports receive configuration BPDUs, the system automatically sets the ports as non-edge ports and starts a new spanning tree calculation process. This causes a change of network topology. Under normal conditions, these ports should not receive configuration BPDUs. However, if someone uses configuration BPDUs maliciously to attack the devices, the network will become unstable.

The spanning tree protocol provides the BPDU guard feature to protect the system against such attacks. When edge ports receive configuration BPDUs on a device with BPDU guard enabled, the device performs the following operations:

• Shuts down these ports.

• Notifies the NMS that these ports have been shut down by the spanning tree protocol.

The device reactivates the shutdown ports after a detection interval. For more information about this detection interval, see Fundamentals Configuration Guide.

BPDU guard does not take effect on loopback-testing-enabled ports. For more information about loopback testing, see Interface Configuration Guide.

Configure BPDU guard on a device with edge ports configured.

To enable BPDU guard: