Ah. Makes sense. I don't think you have to specifically use cloudflare in that case. But I remember CNAME records can't be used for everything... there are some limitations. I know I had issues with dyndns and a domain at some point. I just can't remember the details. I know it didn't work with every registrar / DNS provider. But some of them offer some magic to make some things work. I believe back then we ended up transferring that domain to some other hoster. And my domains are with a company that offers an API. I can just have a small script run in the background that changes around entries and do dyndns that way. But obviously you need to pay attention to things like the time to live for your records and set it accordingly once you do dyndns yourself.