In addition to our previous post: Generally available: Controls to block domain fronting behavior on customer resources, beginning November 8, 2022, all newly created Azure Front Door, Azure Front Door (classic) or Azure CDN Standard from Microsoft (classic) resources will block any HTTP request that exhibits domain fronting behavior.
If you want to block domain fronting for any existing Azure Front Door, Azure Front Door (classic), or Azure CDN Standard from Microsoft (classic) resources created before November 1, 2022, please open a support request. Provide your subscription and Azure Front Door, Azure Front Door (classic), or Azure CDN Standard from Microsoft (classic) resource information in the support request. Once blocking of domain fronting has been enabled, Azure Front Door, Azure Front Door (classic), and Azure CDN Standard from Microsoft (classic) resources will block any HTTP requests that exhibit this behavior.
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