Question : Problem: How can I move a device to another subnet, but keep its old ip address?

We have two networks:
10.0.0.0/8 and 192.168.50.0/24 connected via VPN between two ASA firewalls.

10.0.0.0/8 ---- ASA Firewall -- public address -- internet -- public address -- ASA Firewall ---- 192.168.50.0

We have a special device on the network, 10.0.0.200. Our IT can't manage the device settings, per the vendor's contract. The vendor also charges $250 to change the IP address. After they change the IP address on this device, they'll charge $250 for each other device that needs config changed to point to the NEW address - it gets to be a financial pain.

What i'd like to do is move 10.0.0.200 onto the same network as 192.168.50, and then have other clients on the 10.0.0.0 network still communicate with the device using the 10.0.0.200 address.

I'm sure there's a way to do this (Proxy ARP of some sort), but I don't know if we can with this ASA. Any ideas?

Answer : Problem: How can I move a device to another subnet, but keep its old ip address?

I think the ASA is pretty limited in its capabilities for doing this. Cisco IOS can do it using "ip mobility" but it seems the ASA isn't capable. We decided to shell out the $$ for the vendor to configure the devices.