Service Manual
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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 supports this feature on Dell Networking OS.
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 dierent customer VLANs, on the same stackable
VLAN.
• Interfaces congured using stackable VLAN access or stackable VLAN trunk commands do not switch trac for the default
VLAN. These interfaces are switch trac 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 congured 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 honor
Honor the incoming DEI value by mapping it to an 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-eort.
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VLAN Stacking