The SQL Server AllowAllAzureIps setting
The story about a deep dive into Azure SQL firewall rules and the setting AllowAllAzureIps
This is going to be a longer one. You have been warned! This adventure started last week when I attended the Azure User Group Norway with a session on Azure SQL networking secrets by Dennes Torres.
Dennes showed a setting in the firewall rules on Azure SQL server that said, “Allow Azure services and resources to access this server”. Now you might think “Yeah, I need that for my App Service to access the database”, but in reality, this setting will allow ALL Azure IPs to access the SQL server!