The guy was lazy and didn't write anything...
August 18, 11:37
Test direct access to the source site, in the browser or terminal directly through the server IP or domain name (bypassing the CDN), for example: curl -v http://你的服务器IP
If direct access also fails → the problem is with the server itself.
If direct access succeeds → the problem is with the CDN or an intermediate layer (e.g. Cloudflare).
Comments on:Error 521 Web Server Is Down





