Users 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 OS supports this feature.

For more information about basic VLAN commands, see the Virtual LAN (VLAN) Commands section in Layer 2.

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 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. For more information, see

portmode hybrid.

Topics:

• dei enable

• dei honor

• dei mark

• member

• stack-unit stack-group

VLAN Stacking 2024