If you are changing the host name and or IP address of the machine this will cause the robot to invalidate the probes
You will need to update the robot.cfg and hub.cfg with the new information.
Once the device is up you will need to verify the probes in IM.
If you have tunnels setup or static mappings you would need to update these as well
If you are just changing the robotname in the robot.cfg you need to make sure all references in the robot.cfg and or the hub.cfg are changed as well.