Dell S4048T Configuration Manual page 963

Figure 122. 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: In Dell Networking OS versions prior to 8.2.1.0, the MAC address that Dell
Networking systems use to overwrite the Bridge Group Address on ingress was non-configurable. The value
of the L2PT MAC address was the Dell Networking-unique MAC address, 01-01-e8-00-00-00. As such, with
Service Provider Bridging 963