Forum Discussion
Philippe_Page_2
Cirrus
CirrusError 521: Web server is down - Cloudflare generated error
I have an virtual server created with many websites hosted in it. It has one public IP assigned to it and is NATed to a private IP. The websites are accessible via HTTP and HTTPS. However one website...
JG
Cumulonimbus
Cumulonimbus"521" is a Cloudflare-specific error code, issued when its reverse proxy server's connection to the origin content server was refused. You might want to investigate the issue on the origin content server itself.