sdayman
September 16, 2019, 2:14am
2
When you say “continuously”, is that 100% of the time? I see you’ve done a lot of troubleshooting. What kind of allowlist is that on your server? The firewall? Is there anything in your NGINX logs? Do you have access to firewall logs?
If you can get a RayID for that request, Support should be able to track it down.Login to Cloudflare and then contact Cloudflare Support by clicking on the Get More Help button.
Error
Try the suggestions in this Community Tip to help you fix Error 521 : Web server is down.
Background
A 521 error happens when we are unable to make a TCP connection to your origin server. Specifically, Cloudflare tried to connect to your origin server on port 80 or 443, but received a connection refused error. This is often caused by security or firewall software and happens if the origin server has directly refused Cloudflare’s proxy request.
[Banner in tip catalog]
Quick Fix Ideas
…