Error 521, web server is down. Wordpress site not working.

Hi there @WhyIsThisMyAlias,

I would recommend starting with the following steps on how to troubleshoot common Nginx problems:

https://www.digitalocean.com/community/questions/how-to-troubleshoot-common-nginx-issues-on-linux-server

Feel free to share the output of the commands here so that I could then try to further advise you.

Regards, Bobby

Hello,

I assume that you’re using a CDN service like CloudFlare. The 521 error will usually occur when there is CDN enabled and it will indicate an issue between your local machine and the server or between the CDN and the server itself.

What I usually recommend is to temporarily disable the CDN in order to determine if the issue lies on the droplet, e.g issue with the web-server (Apache/Nginx) or it is DNS related, or some other issue with the CDN.

Error 521 can also occurs when the origin web server refuses connections from Cloudflare. Security solutions at your origin may block legitimate connections from certain Cloudflare IP addresses.

You can find Cloudflare’s IP rages here:

https://www.cloudflare.com/ips/

You can also make sure that port 443 is open with this command:

iptables -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT

Also, you can check our tutorial for whitelisting IPs with iptables:

https://www.digitalocean.com/community/tutorials/iptables-essentials-common-firewall-rules-and-commands#service-web-server

If you’re using CloudFlare you can check this post from their community:

https://community.cloudflare.com/t/how-do-i-temporarily-disable-cloudflare/68798/2

Regards