Our services aren't available right now 🔷 Azure

Azure Front Door: Our services aren't available right now (503/502 from Front Door)

Front Door couldn’t get a valid response from your origin — origin down, health probes failing, TLS/host header mismatch, or a timeout.

Seen on: Azure

Meaning

The page shows an x-azure-ref you can look up. Common: origin certificate name doesn’t match the origin host header, private link/origin firewall blocking Front Door, or responses exceeding the timeout.

Common causes

  • Origin unhealthy or probe path failing
  • Origin host header/certificate mismatch
  • Origin firewall not allowing AzureFrontDoor.Backend service tag
  • Response slower than origin timeout

⚡ Quick fix

  1. Check origin health and probe settings
  2. Set origin host header to a name the origin’s certificate covers
  3. Allow the AzureFrontDoor.Backend service tag / X-Azure-FDID check

Detailed fix by platform

Azure CLI

  1. az afd origin show -g rg --profile-name fd --origin-group-name og --origin-name app --query "{host:hostName,hostHeader:originHostHeader,enabled:enabledState}"

How to diagnose

  1. Reference — x-azure-ref in diagnostics logs
  2. Health — Origin health %
  3. TLS — Certificate CN/SAN vs host header

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

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