Usage Scenario
A user network is connected to each interface of PEs on the carrier network, but all user networks do not belong to the same LAN. Bridge protocol data units (BPDUs) sent from the user networks to PEs are untagged. The PEs, however, need to identify the LANs to which the BPDUs belong. For example, BPDUs from a user network in LAN A must be forwarded to other user networks in LAN A, rather than user networks in LAN B. In addition, BPDUs sent from user networks must not be processed by the CPUs of the PEs on the carrier network.
The following methods can address this problem:
- Configure different roles for devices to identify BPDUs.
- Configure PEs on the carrier network as providers. The well-known destination MAC address of BPDUs sent by the PEs (providers) is 0180-C200-0008. The PEs do not send BPDUs from customers to their CPUs for processing. Instead, the PEs directly forward the BPDUs.
- Configure the devices on user networks as customers. The well-known destination MAC address of BPDUs sent by the devices (customers) is 0180-C200-0000.
- Configure the same role for devices both on the carrier network and user networks. Specifically, configure them as customers. Then, run the bpdu-tunnel stp group-mac command on the devices of the carrier network to replace the well-known destination MAC address of BPDUs from user networks to a specified multicast MAC address.
Follow-up Procedure
Add the interfaces connected to each LAN's user networks to the same VLAN. After receiving BPDUs from user networks, the PEs add VLAN IDs to the BPDUs based on the port default VLAN ID (PVID) of each interface.
In VS mode, this command is supported only by the admin VS.