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 function 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 tasks:
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.
You can configure the BPDU guard feature globally or on a per-edge port basis.
BPDU guard does not take effect on loopback-testing-enabled ports. For more information about loopback testing, see "Configuring Ethernet interfaces."
Enabling BPDU guard globally
The global BPDU guard setting takes effect on all edge ports that are not configured by using the stp port bpdu-protection command.
To enable BPDU guard globally:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enable BPDU guard globally. | stp bpdu-protection | By default, BPDU guard is disabled globally. |
Configuring BPDU guard on an interface
An edge port preferentially uses the port-specific BPDU guard setting. If the port-specific BPDU guard setting is not available, the edge port uses the global BPDU guard setting.
To configure BPDU guard on an interface:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter Layer 2 Ethernet interface view or Layer 2 aggregate interface view. | interface interface-type interface-number | The specified interface must connect to a user terminal rather than another device or shared LAN segment. |
3. Configure BPDU guard. | stp port bpdu-protection { enable | disable } | By default, BPDU guard is not configured on a per-edge port basis. The status of BPDU guard on an interface is the same as the global BPDU status. |