Routing between the same IP remote segments

remi-reszka · ‎11-09-2011

Hi all,

We have a remote site that needs to use the same IP address scheme on one of their segments that is on the main site. I know I can do such routing with VRF over MPLS, VPLS, pseudowires but the problem is that our ISP does not support that.

Is it possible to do it with NAT or VPN technologies?

Thanks for any suggestions.

Remi

darren.g · ‎11-09-2011

remi-reszka wrote:

Hi all,

We have a remote site that needs to use the same IP address scheme on one of their segments that is on the main site. I know I can do such routing with VRF over MPLS, VPLS, pseudowires but the problem is that our ISP does not support that.

Is it possible to do it with NAT or VPN technologies?

Thanks for any suggestions.

Remi

NAT would be the answer, at one end or the other of the link.

At the remote site, you could NAT the whole subnet to one which doesn't exist at your main office, so that as far as the main office is concerned, the remote office is on a completely different subnet range.

You should be able to do one-to-one NAT, depending on your router - turn, say, 192.168.1.200 on the inside to 192.168.40.200 on the outside. Then, at your main office, just have the routing table point to 192.168.40.0 instead of 192.168.1.0.

Cheers.

milan.kulik · ‎11-09-2011

Hi,

this might help you with NATing in your case:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f30.shtml

You just need to be sure all your applications are NAT-capable.

And also you need your provider to route the subnet you are using for NATing to the proper site.

HTH,

Milan