Posted on September 23, 2019 8:57 pm
 |  Asked by Fabrizio Fiore Donati
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Hi all, i want to buy a DCS-7050SX-64-R switch but i need to know if i can do this operation:

I receive some QinQ packet where i can’t configure the outer S-Vlan tag, i need to connect it on our core where i’ve a lot of vlan in use. So, i need to rewrite the Service Vlan tag (only the outer tag) and send the packet to another trunk port that i use as an uplink to our core switch.

For example, port 1 is connected to the operator that send QinQ packet, and receive S-vlan 100, 200, 300.
port 2 is the uplink versus the core switch and i need to transalate S-vlan 100 to 1000, S-vlan 200 to 2000, S-vlan 300 to 3000. Nothing to change on the customer-vlan inside the service vlan.

Can you tell me if 7050 platform can rewrite outer tag ?
From a search into the forum seems to be ok if i need to change only a tag.

Thanks to all

Answered on September 29, 2019 12:25 pm

Hello Fabrizio,

You could use VLAN translation for the rewrite of the outer tag in the packet.This can be configured on the DCS-7050SX-64. More details about the command can be found here :

As an example, we could consider the scenario where the ingress port on the 7050SX device is et1 and the incoming packet is double tagged with an outer-tag ( s-vlan) of 100 and inner tag (c-vlan) of 10. The translation command in place at the incoming interface to rewrite the svlan tag to 1000 would be :

interface Ethernet1
switchport mode trunk
switchport vlan translation 100 1000

The packet would then be bridged as part of vlan 1000 and egress out of any of the member ports of vlan 1000 as configured.

#show vlan 1000

VLAN Name Status Ports
—– ——————————– ——— ——————————-
1000 VLAN1000 active Et2

In the above case , we have configured the egress port(et2) as a trunk port which allows the translated vlan. The trunk port configuration would add the vlan tag 1000 :

interface Ethernet2
switchport trunk allowed vlan 1000
switchport mode trunk

The packet received on your core device would now have an outer-tag ( s-vlan) of 1000 and inner tag (c-vlan) of 10.


Answered on September 29, 2019 7:20 pm

Hi Punit,
thanks for clarification, i saw the manual but i need to be sure that vlan translation works on double tagged packet.
Do you know if ther’s a limit to the number of vlan translation for each port ?

Answered on October 7, 2019 10:21 am

Hi Fabrizio,

We did test the configuration mentioned previously on the DCS-7050SX-64 and can confirm that vlan translation works on double tagged packets.

Regarding any limitations w.r.t the vlan translation per port, since they would vary across platforms, we would request you to reach out to our sales team at and they would be able to help you with the information.


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