An existing Bigfix server (supporting ILMT & MSSQL on the the same) is to be moved to a different domain. There will be no new server, just the server moving to a new domain
If you can add a CNAME you should be able to cater for the changes via DNS so the name in your masthead resolves to the new FQDN across your environment. I’ve migrated to new hardware, new IP, new FQDN on multiple occations and as we use a alias for the server name in the masthead, its easy to cater for the server name or IP changes by simply updating DNS.