Perform the following in the Azure Console:

1. Go to SQL servers
2. For each SQL server
3. Click on Firewall / Virtual Networks
4. Set Allow access to Azure services to OFF’
5. Set firewall rules to limit access to only authorized connections

Perform the following in Azure PowerShell :

1. Disable Default Firewall Rule Allow access to Azure services :
   Remove – AzureRmSqlServerFirewallRule – FirewallRuleName AllowAllWindowsAzureIps – ResourceGroupName & lt;resource group name & gt;- ServerName & lt;server name & gt;
   
   
2. Remove custom Firewall rule :
   Remove – AzureRmSqlServerFirewallRule – FirewallRuleName & lt;firewallRuleName & gt;- ResourceGroupName & lt;resource group name & gt;- ServerName & lt;server name & gt;
   
   
3. Set the appropriate firewall rules :
   Set – AzureRmSqlServerFirewallRule – ResourceGroupName & lt;resource group name & gt;- ServerName & lt;server name & gt;- FirewallRuleName & lt;Fw rule Name & gt;- StartIpAddress & lt;IP Address other than 0.0.0.0 & gt;- EndIpAddress & lt;IP Address other than0.0.0.0 or 255.255.255.255 & gt;

References :

1. https :// docs.microsoft.com / en – us / sql / database – engine / configure – windows / configure – a – windows – firewall – for – database – engine – access?view = sql – server – 2017
2. https :// docs.microsoft.com / en – us / powershell / module / azurerm.sql / get – azurermsqlserverfirewallrule?view = azurermps – 5.2.0
3. https :// docs.microsoft.com / en – us / powershell / module / azurerm.sql / set – azurermsqlserverfirewallrule?view = azurermps – 5.2.0
4. https :// docs.microsoft.com / en – us / powershell / module / azurerm.sql / remove – azurermsqlserverfirewallrule?view = azurermps – 5.2.0
5. https :// docs.microsoft.com / en – us / azure / sql – database / sql – database – firewall – configure
6. https :// docs.microsoft.com / en – us / sql / relational – databases / system – stored – procedures / sp – set – database – firewall – rule – azure – sql – database?view = azuresqldb – current