Connecting 2 switches at L2 (virtual ethernet cable) over VPN. Is it possible ?

Unanswered Question
Jul 12th, 2010


Consider the following setup.

Lab A with Switch SW1

Lab B with Switch SW2

     Lab A and Lab B have an IPSec VPN tunnel over the internet (no mpls).

     They have 2 cisco 2811's between which the ipsec tunnet is established.

Is it possible using some technology (Ethernet over IP ?) to have a "virtual cable" to connect

                     SW1 <-------   virtual ethernet ---------> SW2,

so that they can exchange BPDU's and participate in STP, and form 802.1q trunks etc ??

The idea is to build a switching lab, to learn switching by sharing equipment.

      Its NOT to pass data for production.

The only other alternative is to simply borrow SW2 from Lab2, and physically connect it to SW1.

            But thats no fun !

I dont know too much about VPN's etc, but

Can this be achieved using a GRE tunnel over IpSec, and then bridging the gre / tunnel interface with a spare ethernet interface

on the routers ?

Any ideas if this is possible ?


I have this problem too.
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shahedvoicerite Tue, 07/13/2010 - 08:02

I guess this may be possible using UTI / L2TPv3 on higher end cisco routers (7200 etc).

  Can anyone confirm ?

Another link I found, seems to suggest that this CAN be done over GRE.


   But what I have read so far on Cisco, seems to suggest that GRE can only tunnel IP or PPP frames.

Any input would be appreciated.


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