Mapping one IP to another

[Daniel Davidson]

I have a private network, and I need to let one IP in that private network map to an IP on the public network.  

for example 172.16.1.10 needs behave like IP A.B.C.D on the public network.

Normally, I would just add an interface on the system that was the private network, but that is not an option.  I thought about just running a NAT, but we do not want the systems on the private network to contact any other systems outside of the private network.

Is there a way to do this, and if so can I get pointed in the right direction?

Dan

[Georg Pauwen]

Hello,

' 

it is difficult to understand what you are trying to accomplish. Do you want to map a private to a public IP ?

ip nat inside static 172.16.1.10 A.B.C.D. ?

And what 'other systems outside of the private network' do you want to isolate this IP from ?

Maybe you can draw this out for a better understanding...

[Daniel Davidson]

Ill try again:

I have a system on our public network with IP A.B.C.D

In general, our internal private network we do not want to have access to anything on the public network.

However, all systems on the private network need access to this one system on the public network.

I guess my real questions is what is the best way to make this work?

[Richard Burts]

Dan

Your topology is not clear to us. You talk some about a private network and about a public network. Are they 2 physically separate networks? What kind of devices (switches and/or routers) are providing connectivity for these networks? And you talk about devices in the private network being able to connect to A.B.C.D. Is A.B.C.D a device that physically resides in the network along with the private address hosts? Or is it in a separate network?

If the device that will operate as A.B.C.D is physically in the same network as the private address devices then I would think that some type of static address translation would be your solution. If A.B.C.D is in a separate network then I would think that for the private network there should not be a default route but could be a static route specifically for A.B.C.D.