We have a set of App Services, all integrated within a VNet.
Our Storage Account has Firewall enabled with access given to the Vnet in which all the App Services are integrated.
When I setup a Custom backup to a Container in the Storage account, with Backup/restore over virtual network option Enabled, the custom backup should work.
But it is not the case, it returns following error:
Storage access failed. The remote server returned an error: (403)
Forbidden.. Please delete and recreate backup schedule to mitigate.
It works only when I add all the Outbound IP Addresses of the App Service to the Storage account firewall whitelist.
Why is it so?