There may be further considerations in a particular environment. This is a simplified example.
Note that if the Management Portal is in use, the configuration of the 'Configuration | Reports' tab should be reviewed. If the log location is configured via IP then it may need to be adjusted to point to the new IP.
Another option would be to create and configure a new Defender server with the new IP, then pointing the RADIUS clients to the new IP. This would allow leaving the existing Defender Security server in place until it was confirmed that all clients had been configured to use the new Defender Server.