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 honor
• dei mark
• member
• stack-unit stack-group
• vlan-stack access
• vlan-stack compatible
• vlan-stack dot1p-mapping
• vlan-stack protocol-type
• vlan-stack trunk
dei honor
Honor the incoming DEI value by mapping it to a Dell Networking OS drop precedence. Enter the command once for 0 and once for 1.
Syntax
dei honor {0 | 1} {green | red | yellow}
Parameters
0 | 1 Enter the bit value you want to map to a color.
green | red |
yellow
Choose a color:
• Green: High priority packets that are the least preferred to be dropped.
• Yellow: Lower priority packets that are treated as best-effort.
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