Administrator Guide

VLAN Stacking
With the virtual local area network (VLAN)-stacking feature (also called stackable VLANs and QinQ), you can “stack” VLANs
into one tunnel and switch them through the network transparently.
For more information about basic VLAN commands, see the Virtual LAN (VLAN) Commands section in the Layer 2 chapter.
Important Points to Remember
● If you do not enable the spanning tree protocol (STP) across the stackable VLAN network, STP bridge protocol data units
(BPDUs) from the customer’s networks are tunneled across the stackable VLAN network.
● If you do enable STP across the stackable VLAN network, STP BPDUs from the customer’s networks are consumed and not
tunneled across the stackable VLAN network unless you enable protocol tunneling.
NOTE: For more information about protocol tunneling on the E-Series, see Service Provider Bridging.
● Layer 3 protocols are not supported on a stackable VLAN network.
● Assigning an IP address to a stackable VLAN is supported when all the members are only stackable VLAN trunk ports. IP
addresses on a stackable VLAN-enabled VLAN are not supported if the VLAN contains stackable VLAN access ports. This
facility is provided for the simple network management protocol (SNMP) management over a stackable VLAN-enabled VLAN
containing only stackable VLAN trunk interfaces. Layer 3 routing protocols on such a VLAN are not supported.
● Dell Networking recommends that you do not use the same MAC address, on different customer VLANs, on the same
stackable VLAN.
● Interfaces configured using stackable VLAN access or stackable VLAN trunk commands do not switch traffic for the default
VLAN. These interfaces are switch traffic only when they are added to a non-default VLAN.
● Starting with the Dell Networking OS version 7.8.1 for C-Series and S-Series (Dell Networking OS version 7.7.1 for E-Series,
8.2.1.0 for E-Series ExaScale), a vlan-stack trunk port is also allowed to be configured as a tagged port and as an untagged
port for single-tagged VLANs. When the vlan-stack trunk port is also a member of an untagged vlan, the port must be in
Hybrid mode. See portmode hybrid.
● VLAN stacking is not supported on Port Extender (PE) ports and on LAGs with port extender ports.
● VLAN stacking interface commands are blocked (hidden) on PE ports.
● VLAN stacking interface commands will fail on the VP-LAG (LAG with PE ports).
Topics:
• member
• vlan-stack access
• vlan-stack compatible
• vlan-stack dot1p-mapping
• vlan-stack protocol-type
• vlan-stack trunk
member
Assign a stackable VLAN access or trunk port to a VLAN. The VLAN must contain the vlan-stack compatible command in
its configuration.
C9000 Series
Syntax
member interface
To remove an interface from a Stackable VLAN, use the no member interface command.
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