network address translation (nat) issue

what device/OS/ version are you taking about

Sorry not having mentioned that. We are talking about 2851 Cisco IOS Router @ IOS ver 12.3(8).

maciek

Possibly.

I would expect (but do not know) that an interface can be both "inside" and "outside" at the same time.

There are also a few non-obvious (to me anyway) 'tricks' available.

You can create a loopback interface and use policy routing to force your traffic from the original source interface to the loopback. The loopback could be a nat-outside interface. The traffic could then be router normally but has had an extra NAT operation available.

You can put policy maps on your nat statements. I believe that this allows the full power of policy maps to be applied to natted traffic. Various match and set clauses. No idea what you can actually use this for though other than sending traffic to loopbacks as discussed above.

There is a document that you may find interesting which describes doing NAT on a router with only one interface.

Hi,

Thanks for the hints. I will of course try to implement them. Unfortunately, this is not possible to have both ip nat inside and ip nat outside on the same interface :( this should simplify things but it wouldn't. I have also thought about loopbacks&route-maps but I am not quite sure if it is the simplest solution. I will try it anyway. Thanks also for the link:)

Regards and a happy New Year :)

Maciek