Most of the browsers are thick clients , so it may work in the new browsers but reverse proxies like Application Gateway wont behave like our browsers they only trust the certificates if the backend sends the complete chain. Choose the destination manually as any internet-routable IP address like 1.1.1.1. For a TLS/SSL certificate to be trusted, the backend server certificate must be issued by a CA that's included in the trusted store of Application Gateway. Check whether your server allows this method. Microsoft Word Multiple Choice Questions & Answers, Excel Multiple Choice Questions & Answers, Different Ways to Change Power Button Action in Windows 11. For example, you can use OpenSSL to verify the certificate and its properties and then try reuploading the certificate to the Application Gateway HTTP settings. It is required for docs.microsoft.com GitHub issue linking. Passing negative parameters to a wolframscript. respond within the configured period (the timeout value), it's marked as Unhealthy until it starts responding within the configured timeout period again. In this article I am going to talk about one most common issue "backend certificate not whitelisted", If you check the backend health of the application gateway you will see the error like this "The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. Ensure that you add the correct root certificate to whitelist the backend. I will post any updates here as soon as I have them. In Azure docs, it is clearly documented that you dont have to import Auth certificate in HTTP settings of the backend if your backend application has Global trusted certificate. Ive recently faced with the dreaded 502 Web Server error when dealing with the App Gateway, my Backend Health was screaming unhealthy Backend server certificate is not whitelisted with Application Gateway. Service:<---> Ive deployed 2 Virtual Machines in North Europe (Across Zones 1 and 2) both configured with IIS with 6 sites with different URLs (all with Server Name Indication ticked) installed all the certificates to match their names as-well. When I use v2 SKU with the option to trust the backend certificate from APIM it works. To learn more, see our tips on writing great answers. Sign in I have created an application gateway with 3 backend nodes, when I set the "Http Listener" with all the 3 nodes certificates, the health probe is green. Is there such a thing as "right to be heard" by the authorities? -> it has been taken from application servers by exporting as documented on Microsoft docs for WAF v2. @einarasm read thru the responses from @krish-gh, specifically around leveraging OpenSSL toolkit to query the backend pool for the certificate trust chain, example: %> openssl s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts. #please-close. Cause: When you create a custom probe, you can mark a backend server as Healthy by matching a string from the response body. Now you may ask why it works when you browse the backend directly through browser. But when we have multiple chain certificate and if your backend application/server sends only the leaf the certificate , AppGW will not be able to trust the cert up to the top level domain root. But if the backend health for all the servers in a backend pool is unhealthy or unknown, you might encounter problems when you try to access For example, check whether the database has any issues that might trigger a delay in response. To check the health of your backend pool, you can use the b. To ensure the application gateway can send traffic to the backend pool via an Azure Firewall in the Virtual WAN hub, configure the following user defined route: Address Prefix: Backend pool subnet Hope this helps. This happens when an NSG/UDR/Firewall on the application gateway subnet is blocking traffic on ports 65503-65534 in case of v1 SKU, and ports 65200-65535 in case of the v2 SKU or if the FQDN configured in the backend pool could not be resolved to an IP address. -verify error:num=19:self signed certificate in certificate chain Making statements based on opinion; back them up with references or personal experience. When we check the certificate with the openssl there were following errors: The default route is advertised by an ExpressRoute/VPN connection to a virtual network over BGP. If Pick hostname from backend address is set in the HTTP settings, the backend address pool must contain a valid FQDN. The output should show the full certificate chain of trust, importantly, the root certificate which is the one appgw requires. The following steps help you export the .cer file for your certificate: Use the steps 1 - 8 mentioned in the previous section Export authentication certificate (for v1 SKU) to export the public key from your backend certificate. An existing backend certificate is required to generate the authentication certificates or trusted root certificates required for allowing backend instances with Application Gateway. The error says that Root cert is not whitelisted on the AppGW , but you might have a valid Third party certificate on the backend , and more over if you try to access the backend directly bypassing the Application Gateway you will not see any issues related to certificate in the browser. To restart Application Gateway, you need to. Adding the certificate ensures that the application gateway communicates only with known back-end instances. You can find more details about this issue in our Azure docs, there is a solution already documented inTroubleshoot backend health issues in Azure Application Gateway | Microsoft Docs , Look for the sub topic "Trusted root certificate mismatch", Your email address will not be published. If you have properly added the certificate, and the backend pool is pointing to the custom domain (not the azurewebsites.net domain), then your best options are to either try the V2 SKU, or open a support request to troubleshoot further. To increase the timeout value, follow these steps: Message: Application Gateway could not create a probe for this backend.