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Hi,
I know that this could be an "off-topic" question, but I'm having 
problem changing the default gateway on a VM. In particular, I have 3 VM 
(let's say VM1, VM2 and VM3).

I would like to have the following scenario:

VM1 <--> VM2 <--> VM3

that means that the VM1 and VM3 have to contact VM2 to "talk" each other.

The best solution should be change the default gateway of VM1 and VM3 by 
pointing to VM2 IP address.

Am I wrong? How can do that?

I tryed to add a new default gateway (route add default gw VM2_IP) and 
then try to delete the old default gateway but it is not working.

How can I do it?

Is there any specific procedure since they are VMs and not physical machine?

Thanks,
     Massimo