Cloudflare Error 521: web server is down

Posted April 20, 2020 17.8k views

I have 3 Wordpress sites running on the same Ubuntu machine. I noticed that my websites are not working today. When I checked Cloudflare, I saw that it could not access the server from 443 ports.

I can access the server IP address when I enter the browser, but the domain name does not work.

What caused this?

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3 answers

Hi there @volkanalkilic,

It sounds like that there might be an issue with your Apache or Nginx web server (depending on which one you are using), I would recommend going through these answers here in order to get some more information regarding the actual problem:

  • If you are using Apache:

  • If you are using Nginx:

Another thing that could be causing the issue is if the firewall on your Droplet is blocking Cloudflare if this is the case you need to make sure that you whitelist CloudFlare’s IP ranges so that this does not happen in the future.

You can find Cloudflare’s IP rages here:

Hope that this helps!

Error 521 occurs because the origin web server refuses a connection from Cloudflare. More specifically, Cloudflare tried to connect to your origin server on port 80 or 443 but received a connection refused error

Even after I add ipv4s on i still get the same error please help.