Cloudflare Error 522
Critical
Connection timed out
Cloudflare timed out while contacting the origin server. This usually means the origin firewall is dropping Cloudflare requests or the origin is overloaded.
Impact: Website completely inaccessible
Responsibility
Configuration
This error is usually caused by incorrect DNS, SSL, or firewall configurations.
Common Causes
- Origin firewall drops Cloudflare IP requests
- Severe routing or network layer failure at the origin
- Origin CPU is at 100% and cannot accept new connections
Troubleshooting Guide
1
Whitelist Cloudflare IPs
The most common cause of 522 is origin rate-limiting or anti-DDoS rules dropping Cloudflare IPs. Whitelist all Cloudflare IP ranges in your origin iptables/firewall.
2
Check Origin Load
Intermittent 522 errors suggest the origin server is running out of available connections. Check `top` or `dmesg` for TCP backlog drops or OOM kills.