Administrator Guide

Service Provider Bridging
Service provider bridging provides the ability to add a second VLAN ID tag in an Ethernet frame and is referred to as VLAN
stacking in the Dell Networking OS.
Topics:
• VLAN Stacking
• VLAN Stacking Packet Drop Precedence
• Dynamic Mode CoS for VLAN Stacking
• Layer 2 Protocol Tunneling
• Provider Backbone Bridging
VLAN Stacking
VLAN stacking, also called Q-in-Q, is defined in IEEE 802.1ad — Provider Bridges, which is an amendment to IEEE 802.1Q —
Virtual Bridged Local Area Networks. It enables service providers to use 802.1Q architecture to offer separate VLANs to
customers with no coordination between customers, and minimal coordination between customers and the provider.
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