For the WAN uplink I have a static address assigned. I assume I have to assign this new MX-250 the same IP. That then I would have to remove the old device from the network and turn up the MX-250.
Which really means I can pre-stage it with the IP and the ports shut..Then on the night I want to cut it over shut MX-65 ports and turn MX-250 ports up.
The next question is if I do that., what about the second MX-250 I have for HA? Do I configure the same IP on that one too?