App GW in WAF Mode with Web Apps

Question

I am planning to configure an Application Gateway in WAF Mode which will be sitting infront of my web apps and one function app. I have around 4 web apps and one function app.
One of the web apps is using a custom domain which is like a short URL with SSL binding. So i would like to know when i configure the Application Gateway in WAF mode, what do i need to do to ensure that my web apps are accessed from outside and specially the custom URL is redirecting to the actual backend web app.
Is there anything special i need to do for the configuration of the web app with the custom URL?
Looking forward to some help

Answer 1

@Anonymous , after adding the AppService to the backend pool you should make sure to configure custom health probe by checking the option for picking hostname from backend http settings.

Secondly, you need to configure the listener to listen on your custom domain. Ensure that you provide your custom domain of the app service in the Hostname field. Choose HTTP or HTTPS based on your website requirement. If your website requires HTTPS, then a PFX certificate for the website is required.
Note : Add multisite listener in case of more custom domains.

Now, you need to create an HTTP setting. Then associate the custom probe and save the HTTP settings again. Make sure that “Use for App Service” is unchecked.

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