Access the backend server directly and check the time taken for the server to respond on that page. Issue within certification chain using azure application gateway Next hop: Azure Firewall private IP address. or is that all the backend pools has to serve the request for one application ? Alternatively, you can export the root certificate from a client machine by directly accessing the server (bypassing Application Gateway) through browser and exporting the root certificate from the browser. 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. 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 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. Received response body doesn't contain {string}. 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. Fast-forward 2022, we are also faced with the same issue and getting the same error "Backend server certificate is not whitelisted with Application Gateway" using Application Gateway v1. here is the IP is your backend Application IP , it changes as per your backend pool you can use even use the hostname directly here. Message: Backend certificate is invalid. For new setup, we have noticed that app gateway back-end becomes unhealthy. Azure Nwtworking> Azure Application Gateway: 502 error due to backend certificate not whitelisted in the AppGW, https://techcommunity.microsoft.com/t5/azure-networking-blog/azure-application-gateway-502-error-due-to-backend-certificate/ba-p/3271805, 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. An Azure service that provides a platform-managed, scalable, and highly available application delivery controller as a service. error. Configure that certificate on your backend server. Thanks. If your certificate is working on browser directly hitting the app and not with AppGW then what is the exact problem? 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. More info about Internet Explorer and Microsoft Edge, Export trusted root certificate (for v2 SKU), Overview of TLS termination and end to end TLS with Application Gateway, Application Gateway diagnostics and logging. 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. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Design a site like this with WordPress.com, Troubleshoot backend health issues in Azure Application Gateway | Microsoft Docs. Ensure that you add the correct root certificate to whitelist the backend". Certificates required to allow backend servers - Azure Application Gateway Message: Body of the backend's HTTP response did not match the Select the setting that has the expired certificate, select, The NSG on the Application Gateway subnet is blocking inbound access to ports 65503-65534 (v1 SKU) or 65200-65535 (v2 SKU) from Internet. @TravisCragg-MSFT : Did you find out anything? This is the exact thing what we do when import .CER file in the HTTP Settings of the Application Gateway. Please log in using one of these methods to post your comment: You are commenting using your WordPress.com account. i had this issue for client and split multiple vms ! document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Azure Application Gateway 502 Web Server Backend Certificate not whitelisted. Service: application-gateway; GitHub Login: @vhorne; Microsoft Alias: absha; The text was updated successfully, but these errors were encountered: . Set the destination port as anything, and verify the connectivity. This operation can be completed via Azure PowerShell or Azure CLI. This post has been republished via RSS; it originally appeared at: New blog articles in Microsoft Tech Community. For example: Make sure https probe is configured correctly as well. Below is what happens during SSL negotiation when you have single chain cert and root in the AppGW. Our configuration is similar to this article but we are using WAF V1 sku - https://www.domstamand.com/end-to-end-ssl-solution-using-web-apps-and-azure-application-gateway-multisite-hosting/ How do I bypass Microsoft account login in Windows11? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Best practices and the latest news on Microsoft FastTrack, The employee experience platform to help people thrive at work, Expand your Azure partner-to-partner network, Bringing IT Pros together through In-Person & Virtual events. Backend Nginx works just fine with https, but the application gateway https health probes fail with the message "Backend server certificate is not whitelisted with Application Gateway." What is the deal here? Something that you will see missing is microsft docs is having a default site binding to a SSL certificate without the SNI enabled. Well occasionally send you account related emails. When i check health probe details are following: The certificate that has been uploaded to Application Gateway HTTP settings must match the root certificate of the backend server certificate. Asking for help, clarification, or responding to other answers. privacy statement. Was the error "exactly" the same before you explicitly added the exported root rather than relying on "Digicert" as known authority? In each case, if the backend server doesn't respond successfully, Application Gateway marks the server as Unhealthy and stops forwarding requests to the server. If you want Application Gateway to probe on a different protocol, host name, or path and to recognize a different status code as Healthy, configure a custom probe and associate it with the HTTP settings. Now how can find if my application sending the complete chain , the easy way to find is running openssl from either windows client or Linux client which is present in the same network/subnet of the backend application. From the properties displayed, find the CN of the certificate and enter the same in the host name field of the http settings. Azure Applicaiton Gateway V2 Certification Issue #62578 - Github c. Check to see if there are any default routes (0.0.0.0/0) with the next hop not set as Internet. 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. How to Restart Windows Explorer Process in Windows 11? Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. The output should show the full certificate chain of trust, importantly, the root certificate which is the one appgw requires. The custom DNS server is configured on a virtual network that can't resolve public domain names. To learn more visit https://aka.ms/authcertificatemismatch" I have some questions in regards to application gateway and need help with the same : My issue was due to the root certificate not being presented to appgw, and resulted in the error: "The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. @krish-gh actually it was actually what have i tried firstly but sitouiotion was same. Save the custom probe settings and check whether the backend health shows as Healthy now. d. Otherwise, change the next hop to Internet, select Save, and verify the backend health. Opinions, tips, and news orbiting Microsoft. This configuration further secures end-to-end communication. Solution: If your TLS/SSL certificate has expired, renew the certificate b. https://learn.microsoft.com/en-us/azure/application-gateway/ssl-overview#end-to-end-tls-with-the-v2-sku. AppGW is a PaaS instance , by default you wont get access to the Applicaiton Gateway. Making statements based on opinion; back them up with references or personal experience. I had this same issue. To verify that Application Gateway is healthy and running, go to the Resource Health option in the portal, and verify that the state is Healthy. This is the exact thing what we do when import .CER file in the HTTP Settings of the Application Gateway. 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. For information about how to configure a custom probe, see the documentation page. @EmreMARTiN , following up to see if the support case resolved your issue. 2)How should we get this issue fixed ? e. In the Inbound Rules section, add an inbound rule to allow destination port range 65503-65534 for v1 SKU or 65200-65535 v2 SKU with the Source set as GatewayManager service tag. applications. The v2 SKU is not an option at the moment due to lack of UDR support. This error can also occur if the backend server doesn't exchange the complete chain of the cert, including the Root > Intermediate (if applicable) > Leaf during the TLS handshake. When calculating CR, what is the damage per turn for a monster with multiple attacks? Here is a blog post to fix the issue. Failing endpoint is missing root CA as working one has it. Backend Health page on the Azure portal. Select the root certificate and then select View Certificate. If Internet and private traffic are going through an Azure Firewall hosted in a secured Virtual hub (using Azure Virtual WAN Hub): a. So, I created a default site pointed it to wwwroot, and selected one of my already installed certificates (you can probably PowerShell an SSL for this tbh, but I chose to re-use an already existing one) you dont have to supply a hostname, just a dummy site with an authenticated cert on port 443. To learn how to create NSG rules, see the documentation page. 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. Check to see if a UDR is configured. Configure that certificate on your backend server. 7 19 comments Add a Comment Nillsf 4 yr. ago Cause: After the TCP connection has been established and a TLS handshake is done (if TLS is enabled), Application Gateway will send the probe as an HTTP GET request to the backend server. If Application Gateway can't establish a TCP session on the port specified, the probe is marked as Unhealthy with this message. OpenSSL s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts. However when I replace all the 3 certificates to my CA cert, it goes red and warm me "Backend server certificate is not whitelisted with Application Gateway" The reason why I try to use CA . One pool has 2 servers listed as unhealthy and the error message we see is below: "backend server certificate is not whitelisted with application gateway .Make sure that the certificate uploaded to the application gateway matches with the certificate configured in the backend servers. Otherwise, it will be marked as Unhealthy with this message. Cause: End-to-end SSL with Application Gateway v2 requires the backend server's certificate to be verified in order to deem the server Healthy. Check that the backend responds on the port used for the probe. The HTTP setting of the gateway is configured as follow: I've provided, hopefully, the correct root certificate for the setting. Your certificate is successfully exported. If you create the issue from there, the required details will be auto-populated. Required fields are marked *. 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. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Check the document page that's provided in step 3a to learn more about how to create NSG rules. If your backend is within a VNET not accessible from your local, the you run openssl from a Cloud Shell within VNET. To do end to end TLS, Application Gateway requires the backend instances to be allowed by uploading authentication/trusted root certificates. For example, check whether the database has any issues that might trigger a delay in response. Only HTTP status codes of 200 through 399 are considered healthy. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. You should do this only if the backend has cert which is issued by internal CA, I hope we are clear till now on why we import Authenticate cert in the HTTP settings of the AppGW and when we use the option Use Well Known CA, But the actual problem arises if you are using a Third party Cert or Internal CA Cert which has Intermediate CA and then Leaf certificate, Most of the orgs for security reasons use Root Cert-> Intermediate Cert > Leaf Cert , even Microsoft follows the same for bing , check the screenshot below, Now lets discuss what exactly is the confusion here if we have multiple Chain Cert, When you have single chain certificate , then there will be no confusion with appgw , if your root CA is Global trusted just select Use Trusted Root CA option in HTTPsettings, If you root CA is Internal CA , then import that Top root cert in .cer format and upload it in the HTTP settings. It seems like something changed on the app gateway starting this month. AppGW is a PaaS instance , by default you wont get access to the Applicaiton Gateway. @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.