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vlan translation

Can anyone explain me the concept of vlan translation.Kindly also provide some links.

Thanks in advance.


Re: vlan translation


The term VLAN translation is at least used in a L2VPN environment and also for a Cat6500 feature.

One explanation for a L2VPN can be found at "Setting Up VLAN Translation"


"With 1:1 VLAN translation, the VLAN of the incoming traffic (CE VLAN) is replaced by another VLAN (PE VLAN). It means the SP is now able to handle the situation where incoming traffic from two different customers share the same CE VLAN. The SP can map these two CE VLANs to two different PE VLANs, and customer traffic will not be mixed.

With 2:1 VLAN translation, the double tagged (Q-in-Q) traffic at the U-PE UNI port can be mapped to different flows to achieve service multiplexing. The translation is based on the combination of the CE VLAN (inner tag) and the PE VLAN (outer tag). Without this translation, all the traffic from a Q-in-Q port can only go to one place because it is switched only by the outer tag."

Another explanation of the term is found in "Configuring VLAN Translation"

"On trunk ports, you can translate one VLAN number to another VLAN number, which transfers all traffic received in one VLAN to the other VLAN."

A third somewhat different explanation can be found in "Cisco IOS Switching Services Configuration Guide" at

"VLAN Translation

VLAN translation refers to the ability of the Cisco IOS software to translate between different virtual LANs or between VLAN and non-VLAN encapsulating interfaces at Layer 2. Translation is typically used for selective inter-VLAN switching of non-routable protocols and to extend a single VLAN topology across hybrid switching environments. It is also possible to bridge VLANs on the main interface; the VLAN encapsulating header is preserved. Topology changes in one VLAN domain do not affect a different VLAN."

Well I hope this answers your question. It depends in which environment the term is used.

Hope this helps! please rate all posts.

Regards, Martin