Showing results for 
Search instead for 
Did you mean: 
William Benson

NATing issue (port forwarding) MPLS Outside address is a local address

I'm trying to figure out if what I've been asked to do is even possible.

Current topology for the office in question:

Internet -> ISP Gateway (no control) -> MPLS Cloud -> ( outside) My 2800 Router (full control) -> Local network ( Inside

We have a public IP address that is translated at the ISP gateway to an IP address on our local network before it enters the MPLS cloud.  As it enters my outside interface the destination address is already set to a address (for example

I have been asked to make additional network devices available from the public Internet, but I only have one public IP address assigned to our network.

Is it possible to utilize port forwarding in this situation?  When the traffic comes into my router it's already addressed for the local network, it is passing from an outside to an inside interface.  However the local IP address and the global IP address would both be a part of my local network, since the public IP address is NATed at the ISP gateway to an IP address on my local network.


So the address is for our web server and needs 80 and 443 traffic pointed to it, we have a new surveillance system accessible via an app and an IP address on port 7001.  Given what I've described above can you setup something like this:


ip nat source static tcp 7001 7001


I have no clue if you can even setup a NAT like this when the local and global are both in the same subnet.  If anyone has experience with a scenario like this I would appreciate a little feedback.


Thanks in advance!

Vasilii Mikhailovskii
Rising star


I would say, that the best solution would be to do static translations on ISP gateway (into different internal IP-addresses).