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New Member

3750 - QinQ Multiple VLANS - Vlan mapping

Hi All,

I have a client that uses vlans that already exist on our network (vlan 1,2,3,99,100,200,250...) nethier of us are in a position to change the numbering at this stage.

3750 stacks are on the client side and on my side

what is the best way to configure QinQ or vlan mapping to connect their network to ours without a major outage?

hypothetically, is there a way to have a Ether Channel and trunk all the client vlans to our VMware infrastructure

* map vlan 99 on the client side to vlan 299 on my side

* map vlan 100 on the client side to vlan 298 on my side

* map vlan 200 on the client side to vlan 297 on my side

Thank you in advance

I have googled etc and found alot of info on QinQ for access ports / single vlans but not for multiple vlans / trunks

Hall of Fame Super Blue

Re: 3750 - QinQ Multiple VLANS - Vlan mapping


The vlan numbering may be the same but what about the IP subnets used per vlan.

If the IP subnets are different why not just route between the two switch stacks then the vlans are not visible to each other.

If you need the throughput you could always use L3 etherchannel for additional links.

You could use static routes between each stack or run a dynamic routing protocol to exchange the routes (dependant on the feature sets on your stacks).

Further advantages would be with L3 each site contains it's own broadcasts and there would be no outage for this.

Obviously if the IP subnets are the same then please ignore the above.


New Member

Re: 3750 - QinQ Multiple VLANS - Vlan mapping

Hi Jon, thanks for your quick reply, unfortunately that is not a viable option due to ip addressing and security concers - we are a data centre

Re:3750 - QinQ Multiple VLANS - Vlan mapping

Vlan translation can't be achieved on Cisco 3750.
You would need Cisco ME3400 or 3600 or juniper ex series switches to do it.


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