Azure Front Door suddenly not working

Hello @Hiep To ,

Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.

I understand that your Azure Front Door is suddenly not working and showing the following error "Our services aren't available right now. We're working to restore all services as soon as possible. Please check back soon".

What is the error code that you are seeing? Is it 503?

Please refer the below troubleshooting document for more information:

https://video2.skills-academy.com/en-us/azure/frontdoor/troubleshoot-issues

Please check the HTTP status code that you are receiving when accessing the Front Door.

• HTTP 400 responses from Front Door with "Our services aren't available right now" error could appear before the AFD profile is fully provisioned or for domains/hostnames/protocols that are not registered in Front Door.
• The 400 error can happen if you have not configured a routing rule for the frontend host. A routing rule needs to be explicitly added for the custom domain. Refer: https://video2.skills-academy.com/en-us/azure/frontdoor/troubleshoot-issues#requests-sent-to-the-custom-domain-return-a-400-status-code
• If your environment is HTTPS only and you do not have a HTTP to HTTPS redirect, make sure that you are using HTTPS when you connect to the front door. Refer: https://video2.skills-academy.com/en-us/azure/frontdoor/troubleshoot-issues#azure-front-door-doesnt-redirect-http-to-https
• If you are using own SSL certificate, make sure that the certificate has a complete certificate chain with leaf and intermediate certificates, and root CA must be part of the Microsoft Trusted CA list. Refer: https://video2.skills-academy.com/en-us/azure/frontdoor/front-door-custom-domain-https#option-2-use-your-own-certificate
• 503 responses: If your AFD origin is configured as an IP address, then either disable "EnforceCertificateNameCheck" (not recommended) or change the origin from an IP address to an FQDN to which a valid certificate is issued that matches the origin certificate. Refer: https://video2.skills-academy.com/en-us/azure/frontdoor/troubleshoot-issues#my-origin-is-configured-as-an-ip-address

If you are still facing issues, please share additional details on the error code, backend setup and latest changes that you many have made to the AFD configuration or backend.

Kindly let us know if the above helps or you need further assistance on this issue.

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