Azure Console:
Go to SQL servers
For each SQL server
Click on Firewall and Virtual Networks
Set Allow Azure services and resources to access this server to `OFF'
Set firewall rules to limit access to only authorized connections
Azure PowerShell:
To disable Default Firewall Rule Allow access to Azure services :
Remove-AzureRmSqlServerFirewallRule -FirewallRuleName "AllowAllWindowsAzureIps" -ResourceGroupName -ServerName
To remove custom Firewall rule:
Remove-AzureRmSqlServerFirewallRule -FirewallRuleName -ResourceGroupName -ServerName
To set the appropriate firewall rule:
Set-AzureRmSqlServerFirewallRule -ResourceGroupName -ServerName -FirewallRuleName -StartIpAddress -EndIpAddress
Note: Disabling Allow access to Azure Services
will break all connections to SQL server and Hosted Databases unless custom IP specific rules are not added in Firewall Policy.