Cloudflare - AAPanel with domain - 521 Error - Web down

kamil

Hello,
I have got problem with 521 error on Cloudflare. I've changed my server IP (panel access) to domain, it works however 521 error appears very often. I've add Cloudflare IP4 ips to Fail2Ban whitelist, Firewall whitelist, it does not help
any ideas?

laxadev

kamil If you use fail2ban whitelist these IPs inside Fail2ban.
https://www.cloudflare.com/en-gb/ips/

aaPanel_Jose

kamil
Try the following steps to troubleshoot

Set your domain name resolution to dns only
Set CF's SSL to OFF and then access your website

If there is still a problem, turn off the force SSL of your website on the panel, and then use the http protocol to visit the website to see if it works

rc_br

kamil

Search for Fail2Ban plugin e add credentials (e-mail and token global api) of Cloudflare. It's worked for me. Version panel 7.0.6

Soufian

Turn off SSL from your server.
Try to disable cloudflare (cloud icon) to see if it works, to see if it's your server acting strange or your server not handling CF well.

nephilax

did you turn on fail2ban -cc for this site? If yes, try turn it off and see how it goes
I need to write my own fail2ban rules to work together with cloudflare.

kamil

nephilax I install the fail2ban plugin yesterday, but the problem with cloudflare I've got for more than week

I have a Let's encrypt certificate for my server domain too, however If I turn off orange icon in CF panel there is an error:
NET::ERR_CERT_AUTHORITY_INVALID

kamil

when I turned off SSL (cloud icon) there is an error:
NET::ERR_CERT_AUTHORITY_INVALID

aaP_yandisaja86

Hello, make sure you have instal ssl certificate to your web, you can use lets encrypt,
i have this issue before, after installing ssl to website its fixed
thx