142 CHAPTER 15: BPDU TUNNELING CONFIGURATION
BPDU isolation
When a port receives BPDUs of other networks, the port will discard the BPDUs, so
that they will not take part in spanning tree calculation. Refer to “Configuring
BPDU Isolation” on page 142.
BPDU transparent transmission
As shown in Figure 42, the upper part is the service provider network, and the
lower part represents the customer networks. The customer networks include
network A and network B. Enabling the BPDU tunneling function on the BPDU
input/output devices across the service provider network allows BPDUs of the
customer networks to be transparently transmitted in the service provider
network, and allows each customer network to implement independent spanning
tree calculation, without affecting each other. Refer to “Configuring BPDU
Transparent Transmission” on page 143.
Figure 42 Network hierarchy of BPDU tunneling
■ At the BPDU input side, the device changes the destination MAC address of a
BPDU from a customer network from 0x0180-C200-0000 to a special multicast
MAC address, 0x010F-E200-0003 by default. In the service provider’s network,
the modified BPDUs are forwarded as data packets in the user VLAN.
■ At the packet output side, the device recognizes the BPDU with the destination
MAC address of 0x010F-E200-0003 and restores its original destination MAC
address 0x0180-C200-0000. Then, the device removes the outer tag, and
sends the BPDU to the destination customer network.
n
Make sure, through configuration, that the VLAN tag of the BPDU is neither
changed nor removed during its transparent transmission in the service provider
network; otherwise, the system will fail to transparently transmit the customer
network BPDU correctly.
Configuring BPDU
Isolation
Perform the following tasks to configure BPDU isolation:
Network
Network A Network B
Customer
networks
BPDU input /output
device
BPDU input /output
device
Service provider
network
To do… Use the command… Remarks
Enter system view system-view -
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