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Community Member

Extend a vlan across a WAN

We are are in the process of building a DR site and I was wondering if the following is possible:

We want to have the same vlan defined on two different sites (WAN in between), so if our primary data center is down, services will be virtually moved to a DR site, this way, there is no need to change the ip schema of the servers.

Please see the attached diagram for the details.

So the question is, can we define the same vlan on 2 different sites and move systems that belong to that very same vlan from one site to another.

The attachment has all the details


Re: Extend a vlan across a WAN

Hi Ron

As per my understanding you want an extension to LAN. You want that the server on Data Center & DR server should work in same LAN segment.

You can achive the same using VPLS , But this kind of service will provide by an ISP.(Recommended)

In VPLS you use L2 VFI to create an LAN Segment over WAN.

Using VPLS you can run STP between both switches that reside on different location.

Or else but not sure that whether using L2tpv3 wull support STP transport or not using 802.1q Tunnel.

If you requriment is else please let us know.

Please refer the belwo link for L2tpv3.


Chetan Kumar

Community Member

Re: Extend a vlan across a WAN

I am looking for a solution that is independent of the ISP.

I was thinking of HSRP between the 2 sites but as far as I know HSRP peers need to be on the same LAN.

The other thought would be to change the EIGRP metric on the DR site... not sure if that will work

Re: Extend a vlan across a WAN


As per your requriment you can use LAN Protocols over L2TPv3 to do this but still not sure that your requriment can be full fill by this one.

To achive you requriment you have to use multiple option.

Please refer the below link for same .


Chetan Kumar

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