Note: This is something that may be helpful for a lab environment.
It is not recommended to do this in a production environment without substantial prior testing and validation.
Requirements when trying to move robots between domains
1) Basic network connectivity
2) Hub Name services entries to create static routes between hubs
Hubs discover other hubs by sending out broadcast (UDP) messages. Secondary hubs that are separated from the primary hub by routers or firewalls cannot discover other hubs over UDP. Configure a static route between the hubs. Static routes can be used to connect two hubs that are in the same environment, and reside on different network subnets.
3) Ability to access/reach the robot you're trying to Move
4) Connectivity check - use ping/traceroute/tracert
5) Make sure hub<->robot communication isn't being blocked, e.g., by local/remote firewall(s)
6) Ideally, robots/hubs are resolvable via DNS especially when using the DNS 'lookup' option in the Move utility