I struggle myself a littl ebit when it comes to cdn, a cdn who really speed up my ttfb is nice, but it looks like for the cdn providers trying stealing my ip address in these ways: change nameserver to cdn, use cname with boring www domain -nobody use that today, or trying hide my ip, or us esome cname record point to the cdn url.
Can I not use my root domain in a cdn without that they rank their ip over mine, or rank their cdn url over mine ?
Here is a article about disadvantage seo benefits from cdn:
https://www.gobluemedia.com/blog/content-delivery-networks-cdn-seo/
some of the text here;
"It’s a good start, but when it comes to subdomains, it’s never safe to say that Google will acknowledge your subdomain as a part of your website. Especially in this case, as only images would live under that subdomain, it’s most likely Google will just see that subdomain as a file archive, and an entity not related to your website. It might, or it might not. Google decides based on its own algorithm if it will consider your subdomain a part of your site or not — Google handles subdomains differently based on each website.
Our research indicates that Google handles giant websites such as Times Magazine and others differently than the other ones that are in the billion. Google uses so-called Focused Crawlers when it comes to giant websites that act as the gatekeepers of the web. A Focus Crawler is one of the magic potions Google doesn’t like to talk about much. It basically crawls and indexes a selection of websites with specific setups than it does with other websites. In short: Some websites receive a special treatment.
Don’t expect the same treatment for your web project, unless you and the Google CEO have a special relationship.
The best way to speed up image load are two things: WebP and a fast server.
We’ve researched a couple smaller website projects that have been using CDNs and could see that they were not getting any SEO credits for their images — many of them couldn’t even be found through Google Image Search. Some of the websites we checked were also using CDNs as subdomains, hoping that would make a change — but it does not help.
To sum up, if you are not one of the world’s biggest websites that is being challenged by high traffic and slow load speed, don’t use CDNs for images at all. It is best to keep your images under the same URL if you want to profit from Image SEO, unless your website has millions of of images it can’t handle and you don’t have a choice."
It is like dancing from here to there every day ;
maybe google not rcognize your www domain as same part of your website
google will rank the cdn ip higher than your domain (when the cdn is masking your ip)
google will rank the cdn url higher than your domain
So I ask myself how use a cdn to get fast ttfb speed with my own root domain (without www) or without cdn url or something ?
I will rank my own domain instead of ranking other parties domains (help big sites to get more ranking) - build a serious business is ranking your own domain in the serps not the cdn domain, cdn url or cdn nameservers.
Have a nice day !