Figure 112. VLAN Stacking without L2PT
You might need to transport control traffic transparently through the intermediate network to the other
region. Layer 2 protocol tunneling enables BPDUs to traverse the intermediate network by identifying
frames with the Bridge Group Address, rewriting the destination MAC to a user-configured non-reserved
address, and forwarding the frames. Because the frames now use a unique MAC address, BPDUs are
treated as normal data frames by the switches in the intermediate network core. On egress edge of the
intermediate network, the MAC address rewritten to the original MAC address and forwarded to the
opposing network region (shown in the following illustration).
Dell Networking OS Behavior: The L2PT MAC address is user-configurable, so you can specify an
address that non-Dell Networking systems can recognize and rewrite the address at egress edge.
832 Service Provider Bridging