NAT some traffic to subinterface and not other traffic to same?

[Ashley Gibbon]

Is it possible to NAT some traffic to a subinterface and not NAT other traffic to the same interface.

I need to have two source addresses for the same device which can ontly have one IP address.

I need to have the IP address's 10.18.21.200 and 10.17.21.70 distributed throughout our network, but once the traffic arrives and comes out of a subinterface be destined for 10.17.21.70.

How would you accomplish this please?

The ip address of the subinterface is 10.17.21.1

The config is attached.

Thanks for your time.

[Collin Clark]

Check the following link, I believe it is what you are trying to accomplish.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094e77.shtml#topic10

[Ashley Gibbon]

Thank you for your quick response. I did actually review that page, but I feel my situation is more complex because the old address and the new address are on the same network segment.  I need traffic coming from the s0/0 interface destined for 10.17.21.70 and destined to 10.18.21.200 to leave the ethernet subinterface with a destination of 10.17.21.70.

Thanks

[Collin Clark]

I assume the ethernet sub-interface has an IP in the 10.17.21.x or 10.18.21.x network? Are there other hosts in 10.18.21.200 or just this one?

[Bilal Nawaz]

If you want to route certain types of traffic from a particular origin to one interface and not the other, I believe you could possibly do policy based routing.

e.g. anything coming inbound that is http (or any protocol or source that is specified) traffic can be set to route towards a certain direction. Any other traffic, down another interface or next hop.

With this, controlling the traffic is in place, maybe then you could NAT how you want?

Not too sure if this is the capability you want. White paper on PBR.

http://www.cisco.com/en/US/products/ps6599/products_white_paper09186a00800a4409.shtml

Also a configuration guide

http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfpbr_ps1835_TSD_Products_Configuration_Guide_Chapter.html