Reference 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.

The Dell Networking operating software (FTOS) supports this feature on the Z-9000 platform.

For more information about basic VLAN commands, refer to 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, refer to 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 FTOS version 7.8.1 for C-Series and S-Series (FTOS 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. Refer to portmode hybrid.

dei enable

Make packets eligible for dropping based on their DEI value.

Z9000

Syntax

dei enable

Defaults Packets are colored green; no packets are dropped.

1413