Operation Manual - QinQ-BPDU Tunnel
Quidway S3500-EA Series Ethernet Switches
Chapter 2 BPDU Tunnel Configuration
Huawei Technologies Proprietary
2-2
As shown in
Figure 2-1
, the upper part is the service provider network, and the lower
part represents customer networks. The service provider network comprises BPDU
input/output devices. Network A and network B are customer networks. By enabling the
BPDU tunnel function on the BPDU input/output devices in the service provider
network, you can have BPDUs of customer networks transparently transmitted in the
service provider network.
Network B
Network A
Network
Customer networks
Network B
Network A
Network B
Network A
Network
BPDU input/output
device
Service provider network
BPDU input/output
device
Figure 2-1
Network hierarchy of BPDU tunnel
In this case, BPDUs are processed in the following way in the service provider network.
z
At the BPDU input side, a BPDU is tagged with the VLAN tag assigned to the
customer network by the service provider, and the destination MAC address of the
BPDU is changed to a multicast MAC address (0100-0CCD-CDD0).
Figure 2-2
shows the format of a BPDU traveling in a service provider network.
Figure 2-2
Format of a BPDU packet traveling in a service provider network
z
At the packet output side, BPDUs with the specific multicast MAC addresses are
sent to the customer networks after they are passed to the CPU for being
processed and are restored to the original ones.
