Whitelist CDN IPs
After registering your domain in your Arvancloud account and changing the Nameservers, you need to whitelist the CDN edge servers’ IP on your website’s origin server in order to activate CDN.
When your website uses the Arvancloud CDN Service, the CDN IPs redirect all of the traffic that is not cached to your main server.
If your website’s main server (or your shared website host) uses a general firewall, this traffic will be recognized as an attack, and the CDN IPs will be blocked.
Therefore, your origin server will not respond to the requests sent from the CDN edge servers, and your website will not load properly.
You need to whitelist all of the Arvancloud IPs for your firewall to solve this problem. Or you can inform your hosting company to whitelist those IPs.
The list of the CDN edge servers’ IPs is in the following link, and it is updated regularly. You can provide these links to your hosting company to have them whitelisted.