If you are using SMU, I suggest changing the IP address in the opposite controller and then test that you have access to the other controller's SMU. Then change the opposite controllers IP address.
If you are on 10.0.0.2 controller and change the IP address you will loose the connection until you reconnect to the new IP address. Which is why I usually change one IP address at a time and then confirm I can access the new IP address and SMU.
Cheers,
Shawn