In Azure docs, it is clearly documented that you dont have import Auth certificate in HTTP settings of the backend if your backend application has Global trusted certificate. @krish-gh actually it was actually what have i tried firstly but sitouiotion was same. Default route advertised by the ExpressRoute/VPN connection to the virtual network over BGP: a. 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. here is the sample command you need to run, from the linux box that can connect to the backend application. This is the exact thing what we do when import .CER file in the HTTP Settings of the Application Gateway. Was the error "exactly" the same before you explicitly added the exported root rather than relying on "Digicert" as known authority? Check the backend server's health and whether the services are running. Export trusted root certificate (for v2 SKU): Azure Applicaiton Gateway V2 Certification Issue, https://docs.microsoft.com/en-us/azure/application-gateway/certificates-for-backend-authentication#export-trusted-root-certificate-for-v2-sku, https://docs.microsoft.com/en-us/azure/application-gateway/ssl-overview#end-to-end-tls-with-the-v2-sku, Enabling end to end TLS on Azure Application Gateway, articles/application-gateway/ssl-overview.md, https://docs.microsoft.com/en-us/azure/cloud-shell/overview. I have some questions in regards to application gateway and need help with the same : 1)Is that application gateway can be configured with multiple backend pools and each pool can serve a request for different applications ? For File name, name the certificate file. Error message shown - Backend server certificate is not whitelisted with Application Gateway. For the server certificate to be trusted we need the Root certificate in Trusted Root Cert Store , usually if you are having certs issued by Godaddy,Digicert,Vergion like Third party Vendors you dont have to do anything because they are automatically trusted by your client/browser. Message: The root certificate of the server certificate used by the backend doesn't match the trusted root certificate added to the application gateway. Ensure that you add the correct root certificate to whitelist the backend". The certificate that has been uploaded to Application Gateway HTTP settings must match the root certificate of the backend server certificate. If you open your certificate with Notepad and it doesn't look similar to this, typically this means you didn't export it using the Base-64 encoded X.509(.CER) format. If the output doesn't show the complete chain of the certificate being returned, export the certificate again with the complete chain, including the root certificate. Message: The backend health status could not be retrieved. Here is a blog post to fix the issue. 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. Hope this helps. For details on this Openssl command you can refer toTroubleshoot backend health issues in Azure Application Gateway | Microsoft Docs , Look for the sub topic "Trusted root certificate mismatch". If the port mentioned is not the desired port, enter the correct port number for Application Gateway to connect to the backend server. To resolve the issue, follow these steps. An authentication certificate is required to allow backend instances in Application Gateway v1 SKU. Were you able to reproduce this scenario and check? Select the root certificate and then select View Certificate. Your email address will not be published. To allow this access, upload trusted root certificates (for v2 SKU) of the back-end servers to the application gateway. https://learn.microsoft.com/en-us/azure/application-gateway/ssl-overview#end-to-end-tls-with-the-v2-sku. Move to the Certification Path view to view the certification authority. In this example, you'll use a TLS/SSL certificate for the backend certificate and export its public key to be used as . Sorry my bad, this is actually now working - I just needed to have the CN in the certificate match with what was set in backend pool. Server will send its Certificate and because AppGW will already have its Root Cert, it verifies the backend server certificate and finds that it was issued by the Root cert which it is Trusting and they it starts connecting on HTTPs further for probing. Once the public key has been exported, open the file. To troubleshoot this issue, check the Details column on the Backend Health tab. You signed in with another tab or window. After you've figured out the time taken for the application to respond, select the. Required fields are marked *. Sharing best practices for building any app with .NET. @EmreMARTiN , you mentioned your backend certificate is from "Digicert" which is already a well-known trusted CA. Nice article mate! I am opening a PR to update the End-to-End Howto guide with a description of the error and a link to the SSL overview. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Azure Application Gateway health probe error with "Backend server certificate is not whitelisted with Application Gateway", When AI meets IP: Can artists sue AI imitators? For the server certificate to be trusted we need the Root certificate in Trusted Root Cert Store , usually if you are having certs issued by Godaddy,Digicert,Vergion like Third party Vendors you dont have to do anything because they are automatically trusted by your client/browser. Otherwise, it will be marked as Unhealthy with this message. On the Details tab, select the Copy to File option and save the file in the Base-64 encoded X.509 (.CER) format. with your vendor and update the server settings with the new But if this message is displayed, it suggests that Application Gateway couldn't successfully resolve the IP address of the FQDN entered. OpenSSL s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Now, this is the frustrating partwithin IIS, all of my sites are bound too each specified certificate (sharing a single cert across all the sites wont work for this scenario because of the difference in SSL and URL names), What the MSFT document (https://docs.microsoft.com/en-us/azure/application-gateway/application-gateway-end-to-end-ssl-powershell) fails to tell you, is that you need a Default SITE binding to a certificate, without SNI ticked. Set the destination port as anything, and verify the connectivity. If you are using Azure Application Gateway as Layer 7 WAF for End to End SSL connectivity , you might have come across Certificate related issues most of the times. What are the advantages of running a power tool on 240 V vs 120 V? Microsoft Word Multiple Choice Questions & Answers, Excel Multiple Choice Questions & Answers, Different Ways to Change Power Button Action in Windows 11. Only HTTP status codes of 200 through 399 are considered healthy. here is the sample command you need to run, from the machine that can connect to the backend server/application. d. If an NSG is configured, search for that NSG resource on the Search tab or under All resources. @EmreMARTiN , following up to see if the support case resolved your issue. If you're aware of the application's behavior and it should respond only after the timeout value, increase the timeout value from the custom probe settings. here is what happens in in Multiple chain certificate. Also, please let me know your ticket number so that I can track it internally. Check the backend server's health and whether the services are running. @TravisCragg-MSFT: Any luck? Or, if Pick hostname from backend HTTP settings is selected in the custom probe, SNI will be set from the host name mentioned in the HTTP settings. I have the same issue, Root cert is DigiCert. Also check whether any NSG/UDR/Firewall is blocking access to the Ip and port of this backend. 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. In this article I am going to talk about one most common issue "backend certificate not whitelisted" . This article describes the symptoms, cause, and resolution for each of the errors shown. If your cert is issued by Internal Root CA , you would have export the root cert and import it the Trust Root Store in the Client. This causes SSL/TLS negoatiation failure and AppGW marks the backend as unhealthy because it is not able to initiate the probe. I have tried to upload root CA instead of using well-known CA and the issue persist. 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. Expected:{HTTPStatusCode0} Received:{HTTPStatusCode1}. security issue in which Application Gateway marks the backend server as Unhealthy. Configure that certificate on your backend server. How to Allow or Prevent Themes to Change Desktop Icons in Desktop Icon Settings in Windows 11? "The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway". Version Independent ID: <---> If the output doesnt show the complete chain of the certificate being returned, export the certificate again with the complete chain, including the root certificate. Verify that the FQDN entered in the backend pool is correct and that it's a public domain, then try to resolve it from your local machine. Message: Application Gateway could not connect to the backend. You can add this to the application gateway to allow your backend servers for end to end TLS encryption. You must be a registered user to add a comment. c. Check the user-defined routes (UDR) settings of Application Gateway and the backend server's subnet for any routing anomalies. For example, you can configure Application Gateway to accept "unauthorized" as a string to match. I am using the base64 encoded .CER file without the chain (w/o intermediary and root) at the https setting of the backend settings of application gateway and it is working fine (see image below). Adding the certificate ensures that the application gateway communicates only with known back-end instances. "Backend server certificate is not whitelisted with Application Gateway." Something that you will see missing is microsft docs is having a default site binding to a SSL certificate without the SNI enabled. 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