Cloudflare 522 Connection Timed Out

Plain-English meaning

Cloudflare could not complete TCP handshake to origin in time.

Why it happens

Origin is slow/unreachable at network or listener layer.

Common causes

  • Origin service down
  • Firewall blocks Cloudflare edge ranges
  • SYN backlog saturation
  • DNS points to stale origin IP

What to check first

Verify listener on 80/443, audit firewall rules, and check packet loss/latency from origin network.

How to fix it

Restore origin availability, allow Cloudflare IP ranges, and tune origin/network capacity for connection bursts.

Example signal

Error 522: Connection timed out

Related links

404 · 429 · 500 · 502 · 503 · 504 · Cloudflare 522 · Nginx 499 · ERR_CONNECTION_REFUSED

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