You can configure VLAN-based bridge protocol data unit (BPDU) tunneling based on the different roles of provider edges (PEs) and customer edges (CEs) or on the same role of PEs and CEs (VLAN is short for virtual local area network). After VLAN-based BPDU tunneling is configured, the PEs do not send BPDUs to their CPUs for processing. Instead, they transparently transmit the BPDUs through BPDU tunnels over the Layer 2 network of the carrier network to user networks.
You can configure VLAN-based BPDU tunneling based on the different roles of PEs and CEs or on the same role of PEs and CEs.
Different roles of PEs and CEs: CEs are customers, and PEs are providers.
Same role of PEs and CEs: CEs and PEs are both customers.
If PEs and CEs are configured with different roles, the PEs can transparently transmit BPDUs sent by the CEs. In this case, you do not need to enable BPDU tunneling on the interfaces of the PEs.
If PEs and CEs have the same role, the PEs cannot transparently transmit BPDUs sent by the CEs. In this case, you need to enable BPDU tunneling on the PE interfaces.