[c-nsp] splitting a subnet into two locations

[Ed Ravin]

On Thu, Feb 01, 2007 at 05:33:01PM -0800, Rudy Setiawan wrote:
> I am trying to get the same subnet from one network to another network over
> a layer-3.
> So that everyone can see the PC who is on different offices is able to see
> each other's PC/Printers.
> 
> I know that OpenVPN can do the job but I would like to find out if Cisco
> gears can do that with some sort of tunneling.

I did it without any tunneling when moving a data center last year -
we announced the subnet into OSPF as originating from one location,
and then added /32 routes for the individual machines as we moved
them to the new location.  We turned on proxy-arp at both locations
so the machines on one side could route to the other.  We also had to
redo our hard-coded anti-spoofing ACLs during the move.