H3C Technologies H3C S10500 Series Switches - Manual (Page 106)

95
• Device A connects to a third-party device that has a different spanning tree implementation. Both
devices are in the same region.
• The third-party device (Device B) is the regional root bridge, and Device A is the downstream
device.
Figure 26 No Agreement Check configuration
2. Configuration procedure
# Enable No Agreement Check on GigabitEthernet 1/0/1 of Device A.
system-view
[DeviceA] interface gigabitethernet 1/0/1
[DeviceA-GigabitEthernet1/0/1] stp no-agreement-check
Configuring protection functions
A spanning tree device supports the following protection functions:
• BPDU guard
• Root guard
• Loop guard
• TC-BPDU guard
Configuration prerequisites
The spanning tree feature has been correctly configured on the device.
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 forges 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.
With the BPDU guard function enabled on the devices, when edge ports receive configuration BPDUs,
the system closes these ports and notifies the NMS that these ports have been closed by the spanning tree
protocol. The device will reactivate the closed ports after a detection interval. For more information about
this detection interval, see Fundamentals Configuration Guide.
Configure BPDU guard on a device with edge ports configured.
Follow these steps to enable BPDU guard:
To do... Use the command... Remarks
Enter system view system-view —