Origin Servers not available through Cloudflare but directly accessible

Hello Everyone,

I am facing a serious issue with accessing our origin servers. If i pause the cloudflare access, our origin server responds perfectly without any issues. If i turn on cloudflare, it does not work anymore. and i get connection timeouts with error 522.

I have 4 origin servers hosted behind a CF load balancer and the load balancer is notifying me that none of my servers are accessible. But 2 menu options down the health check says they are running fine without any issues. I can access the servers directly without any issues.

Can any advise me on what to do?

Thanks.

Did you make sure that Cloudflare’s IPs aren’t blocked by a firewall?

Yes, i have. The problem is, it happened yesterday, i kept getting timeouts for 3-4 hours and then agian it was fine. This morning and same thing happened and still not yet working.

It does sound like you have not added the complete set of IP ranges used by Cloudflare to your Origin firewall. Do you have any firewall logs (or even Wireshark traces) from your Firewall?

The complete set of IP addresses is documented, but it is subject to change so you would need to automate updates, or notifications of changes to the published lists.