Subject: DMZ Server cannot connect to SQL Server
From: Rickie George <[email-masked]>
To: Microix Support <[email-masked]>
Date: Tue, 15 Feb 2022 10:39:13 -0500

Microsoft resources to help configure DMZ for SQL access

Configure Windows Firewall - SQL Server | Microsoft Docs

Configure a Windows Firewall for Database Engine Access - SQL Server | Microsoft
Docs

Configure a Server to Listen on a Specific TCP Port - SQL Server | Microsoft Docs

How to replicate the DMZ Server SQL Access error:

SQL Server: No Inbound access to port 1433 and SQL Network Configuration for TCPIP is disabled

Changes to the DMZ IIS Server and Private SQL Server to allow HTTP/HTTPS and SQL Server access:

SQL Server Configuration Manger:

SQL Server (Private Server) allow inbound for port 1433 TCP and 1434 UDP

IIS server (DMZ) allow inbound for ports 80 and 443 (HTTP/HTTPS)