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Service Provider Bridging
Service provider bridging is composed of virtual local area network (VLAN) Stacking, Layer 2 Protocol
Tunneling, and Provider Backbone Bridging as described in the Dell Networking OS Configuration Guide
Service Provider Bridging chapter.
This chapter includes command line information (CLI) for the Dell Networking operating software Layer 2
Protocol Tunneling (L2PT). L2PT enables protocols to tunnel through an 802.1q tunnel.
Dell Networking OS supports L2PT on Dell Networking OS.
For more information, refer to VLAN Stacking, Spanning Tree Protocol (STP), and GARP VLAN Registration
(GVRP).
Important Points to Remember
• L2PT is enabled at the interface VLAN-Stack VLAN level. For more information about Stackable VLAN
(VLAN-Stacking) commands, refer to VLAN Stacking.
• The default behavior is to disable protocol packet tunneling through the 802.1q tunnel.
• Rate-limiting is required to protect against bridge protocol data units (BPDU) attacks.
• A port channel (including through link aggregation control protocol [LACP]) can be configured as a
VLAN-Stack access or trunk port.
• Address resolution protocol (ARP) packets work as expected across the tunnel.
• Far-end failure detection (FEFD) works the same as with Layer 2 links.
• Protocols that use Multicast MAC addresses (for example, open shortest path first [OSPF]) work as
expected and carry over to the other end of the VLAN-Stack VLAN.

debug protocol-tunnel

Enable debugging to ensure incoming packets are received and rewritten to a new MAC address.
Syntax debug protocol-tunnel interface {in | out | both} [vlan vlan-
id] [count value]
To disable debugging, use the no debug protocol-tunnel interface {in |
out | both} [vlan vlan-id] [count value] command.
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