VLAN Translation in a PVLAN

VLAN translation provides the ability to translate the 802.1Q tags for several VLANs into a single VLAN tag. VLAN translation is an optional component in a PVLAN.

VLAN translation allows you to aggregate Layer 2 VLAN traffic from multiple clients into a single uplink VLAN, improving VLAN scaling. The following figure shows an application of VLAN translation.


The VLAN translation feature described in VLAN Translation is provided for those who are already familiar with the ExtremeWare VLAN translation feature. If you have time to use the PVLAN implementation and do not have scripts that use the ExtremeWare commands, we suggest that you use the PVLAN feature, as it provides the same functionality with additional features.
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VLAN Translation Application

In the figure, VLANs 101, 102, and 103 are subscriber VLANS that carry data traffic while VLANs 201, 202, and 203 are subscriber VLANs that carry voice traffic. The voice and data traffic are combined on integrated access devices (IADs) that connect to the VLAN translation switch. Each of the three clusters of phones and PCs uses two VLANs to separate the voice and data traffic. As the traffic is combined, the six VLANs are translated into two network VLANs, VLAN1 and VLAN2. This simplifies administration, and scales much better for large installations.

Conceptually, this is very similar to Layer 3 VLAN aggregation (superVLANS and subVLANs).

The primary differences between these two features are:
  • VLAN translation is strictly a Layer 2 feature.

  • VLAN translation does not allow communication between the subscriber VLANs.