HTTP status code
Origin Is Unreachable
Cloudflare-specific: the origin could not be routed to at all.
Cloudflare could not find a network path to your origin. This is more fundamental than a timeout — the address itself appears unroutable, which usually means it is wrong rather than down.
Check the A record in Cloudflare DNS points at the current origin IP. After migrating servers or recreating a cloud instance, a stale record is by far the most likely explanation.
These three Cloudflare errors describe three different failures and the distinction saves real debugging time. 521 means your server actively refused the connection — something answered and said no. 522 means nothing answered before the timeout. 523 means Cloudflare could not even find a route to the address.\n\nThat progression maps to what to check. A refusal points at a stopped process or a firewall rejecting traffic. Silence points at packets being dropped or a saturated connection backlog. Unroutable points at the address itself being wrong — which is why 523 so often follows a server migration where the DNS record was never updated.\n\nCheck the A record in Cloudflare DNS against the current origin IP, and confirm the record is not pointing at a private address. A record on an orange-clouded hostname must resolve to a publicly routable IP.
A 523 is a total outage and usually follows an infrastructure change. Monitoring the public hostname catches it immediately after a migration.
Monitor for 523 responses freeNearly always a DNS record pointing at an IP that is no longer valid — most often after a server migration or an instance being recreated with a new address.
Pingura checks your endpoints from five regions and alerts on the status code, not just reachability.
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