An Azure service that provides a cloud content delivery network with threat protection.
Based on the information provided, this does appear more like a control plane or feature registration issue than a problem with the WAF policy configuration itself.
The indicators are:
-
Microsoft.Network/AllowFrontdoorremains Pending. -
Microsoft.NetworkandMicrosoft.Cdnare already Registered. - Azure Front Door Standard resources (profile, endpoint, origin group, origin) deploy successfully.
- A minimal standalone
Standard_AzureFrontDoorWAF policy fails before any association with a Front Door profile. - The error is returned during resource validation:"Policy ArmResourceId has incorrect formatting". [learn.microsoft.com]
One additional point worth validating is whether the deployment payload contains any WAF policy resource IDs that are being generated or referenced incorrectly. Although the error often points to a malformed ARM resource ID, your minimal reproduction suggests the validation layer may be incorrectly interpreting the request while the Front Door feature registration remains incomplete.
A few checks that have not yet been discussed in the thread by other ans as well:
- Verify the API version being used for
Microsoft.Network/FrontDoorWebApplicationFirewallPolicies.
- If deploying via ARM/Bicep/Terraform, test with the latest generally available API version supported for Azure Front Door WAF.
- Older API versions can sometimes produce validation errors that do not accurately reflect the underlying issue.
- Compare the generated resource ID against the expected format:
-
/subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.Network/FrontDoorWebApplicationFirewallPolicies/{policy-name}
-
- Review the deployment operation JSON for any hidden references to:
- Security policies
- Front Door associations
- Managed rule sets
- Custom rule definitions
Given that AllowFrontdoor remains Pending, and the issue reproduces with a minimal standalone policy, I would focus on the registration state rather than spending time troubleshooting DNS, certificates, Key Vault integrations, routes, origins, or WAF rule definitions. The evidence currently points to a subscription-level feature state mismatch rather than an issue with the WAF configuration itself. [learn.microsoft.com]
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