Many developers would like their website to have support for IPv6 connectivity. Unfortunately IPv6 is not yet widely supported for most Azure services, including App Service, which includes Web Apps/Function Apps/Bot Service/etc.
The good news is that this is possible to achieve using Azure Front Door as a frontend, which does support IPv6. The Azure Front Door will then reach the Web App over IPv4.
Using this tool I tested a simple Azure Web App, which is not ready for IPv6. The tool performs a DNS AAAA record lookup, to discover an IPv6 address.
Here I have setup an Azure Front Door with custom domain http://ipv6.patrickob.com -> CNAME record pointing at the Front Door hostname xxxxxx.azurefd.net. You do not need to use a custom domain, you can also use the default Front Door hostname. The Front Door hostname has a DNS AAAA record which is found and supports IPv6.
I am now ready for IPv6 clients to reach my App Service 😊. This is important because certain businesses require IPv6 support, including all federal government public websites.
Of course, this is only one of the many possibilities when using Azure Front Door as the entry point for your application or website. Read more here: https://docs.microsoft.com/en-us/azure/frontdoor/front-door-overview.
Watch this feature request for updates on IPv6 in the Azure platform: https://feedback.azure.com/forums/217313-networking/suggestions/4992369-support-ipv6-throughout-the-azure-platform.