Please help with the below requirement. Essentially what I am looking to discover is does cisco have a feature that allows a router to respond to any arp reqest..

The requirement that has been requested is this :

In a staging lab a device will be put on a network for testing. This device will always establish an IPSec tunnel to our main Lab firewalls. Due to the fact that each device that comes in will have a pre-configured (almost random) ip that cannot be reconfigured. The solution needs to have a router that will respond to any arp request and Nat outbound. Since there will only be one device on the staging lab and that device will always try to hit the same lab firewalls, This should be plausible. Essentially the router would be responding as if he was the DG of any device in his internal network.

Does anyone know of a solution that Cisco provides to solve this requirement.

Thank you for you time.