Error 522 from an Origin Rule pointing at a reserved address

Not specified by the original author.

Origin Rule 522: reserved-address targets

A specific 522 variant: your Origin Rule's resolve override points at a hostname whose A record is a reserved address such as 100:: or 192.0.2.0. Cloudflare cannot route to it, so the request fails as a 522.

How it happens

• Placeholder or documentation IPs left in the override target from testing.
• The target hostname's DNS changed (or was never real) and now resolves to a reserved range.
• Confusing the override target (where Cloudflare should send the request) with an identifier (a label that was never meant to resolve).

Diagnosis

1. Read the Origin Rule and extract the resolve-override hostname.
2. dig it: confirm it resolves to a real, routable origin IP.
3. curl the origin directly at that IP with the right Host header to confirm it answers.

Checklist

• Every resolve override target must resolve to a routable IP; test with dig, not by reading the config.
• Treat 522s that started right after an Origin Rule change as guilty until proven innocent: revert the rule and re-test.
• Document what each override target is and who owns its DNS.

Verified against the live Error 522 support doc: Origin Rule pointing to a Worker route whose hostname A record is a reserved address (100::, 192.0.2.0) returns 522. Ref: https://developers.cloudflare.com/support/troubleshooting/http-status-codes/cloudflare-5xx-errors/error-522/