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I believe you are referring to Enable custom domains in Azure Active Directory B2C
- I don't see any official recommendations from Azure documentation highlighting the use of App Gateway
- While App Gateway is also a reverse proxy, you must note that App Gateway is a regional resource while AFD and AAD (Entra ID) are distributed globally.
- This means users from different regions than the App Gateway will experience a higher latency than compared to users who access the Entra login directly or via AFD.
While this is technically achievable, I recommend you not to use App Gateway.
If you would like to use App gateway still,
- As there are no documentations available, you have to do a test configuration in a lower/dev environment
- Make sure you follow all the recommendations in Hostname preservation and review it's Potential problems
- You can follow the same steps in AFD Documentation, and configure
Once again, as this is not a documented set up, please make sure you try this in a lower/dev/test environment.
Kindly let us know if this helps or you need further assistance on this issue.
Thanks,
Kapil
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