Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Is there a way to map different VLANs over a trunk?

I have an office where we have to trunk our vlans over a third-party provider switch. They cannot use our VLAN numbers because other customers of theirs use them. We cannot use their numbers because they are not permanent. So is there a way to map our VLAN numbers to their VLAN numbers over the trunk between our switches. For instance we want VLAN 10 on our switch to map to VLAN 600 on their side.



Re: Is there a way to map different VLANs over a trunk?

Well, if it is only one vlan the case than do not use a trunk. Instead of using the link as a trunk use it as access port and assign this port to VLAN 600. Therefore, anything comming from your switches to their side will be tagged with VLAN 600. This has to be done on their switch only.

I hope this helps and rate if you find it helpfull,


Re: Is there a way to map different VLANs over a trunk?

This might be one of the rare occasions where QinQ might be useful.

You may then use whatever vlanid is offered and send your own encapsulation along with it.

A completely different approach might be to use ip routing instead. vlans can often be distinguisghed by the ip ranges that are sent over them. You may well find it possible to send everything over a trunk and sort it out at layer3 on the other side. Even QoS can be preserved if you use dscp instead of cos. The only requirement is that you have sufficient bandwidth. Main disadvantage: you will have to maintain two separate vtp domains.