Setup is unable to access the SQL UDP Port 1434 on the specified SQL Server

When setting up SQL and configuring some applications. The following error might be prompted “Setup is unable to access the SQL UDP port 1434 on the specified SQL server”. This means that the setup requires access to the SQL UDP port 1434 to retrieve the TCP port assignment information from the SQL server. Please see DNS uses TCP and UDP, How to uninstall Microsoft SQL Server on Windows. Also, see how to change the default RDP port in Windows.
Windows Firewall help prevent unauthorized access to the Server. To access an instance of the SQL Server through a firewall. You must configure the firewall on the computer that is running SQL Server. When working locally, you do not need to do this.
Please see how to create a Windows firewall rule on Windows, Remote WMI Connection: How to enable or disable WMI Traffic Using Firewall UI, and How to enable or disable a Remote WMI Connection in Windows.
SQL Server Browser Service (UDP port 1434)
The SQL Server browser service listens for incoming connections to a named instance. The service provides the client the TCP port number that corresponds to that named instance.
Usually, the SQL Server Browser service is started whenever named instances of the Database Engine are used. The SQL Server Browser service isn’t required if the client is configured to connect to the specific port of the named instance.
Why the error “Setup is unable to access the SQL UDP port 1434”
As mentioned in the first paragraph above, the setup requires access to the SQL UDP port on 1434. When the installer connects to the SQL Server using the credentials.
If the installer can’t automatically determine the port. The following error message appears “Setup was unable to access the SQL UDP port 1434”. Click OK to return to the Database Information page as shown in the image below.

You can also manually create these firewall rules. The Windows Firewall with Advanced Security MMC snap-in lets you configure more advanced firewall settings.
Note: This is not a firewall issue as we are not accessing the SQL instance through the firewall. Even when you create these firewall rules, yet, it will FAIL.

Just in case you wish to create the firewall rules for a different task. Below are the commands to create a TCP port 1433 and UDP port 1434 for SQL Server default instance, and SQL Server Browser Service.
New-NetFirewallRule -DisplayName "SQLServer default instance" -Direction Inbound -LocalPort 1433 -Protocol TCP -Action Allow
New-NetFirewallRule -DisplayName "SQLServer Browser service" -Direction Inbound -LocalPort 1434 -Protocol UDP -Action Allow
Solution
Return to the SQL Server Configuration Manager. Click on “SQL Server Network Configuration” in the left pane and right-click the “TCP/IP” protocol and select “Properties”.
Note: Ensure TCP/IP is Enabled as this is disabled by default.
Click the IP addresses tab, and make sure Enabled is set to Yes for each active IP address. This will ensure that all the IP addresses on your Trellix ePolicy Server is capable of communicating to your SQL server.

Also, navigate to the “IP Addresses” tab and scroll down to the IPALL section. If you wish to use the default port, remove the value for TCP Dynamic Ports (leaving it blank).
You can also leave as you will manually specify the TCP port. Enter port 1433 for TCP port.

You can now restart the service to make sure that your changes take effect.

Note: When you use dynamic ports, the SQL Browser service must be running on the SQL Server. If the value for TCP Dynamic Ports is blank, your SQL Server is using a static port, and the value for this port is shown in the TCP Port field.
Once done restart the SQL instance and start the ePolicy Server installation again. Select SQL Server Services, select SQL Server on the right window, and then click Restart.

You should be able to continue with your installation as shown below. You can refer to this link to learn more about remotely accessing your SQL Server.

I hope you found this guide useful on “Setup is unable to access the SQL UDP port 1434 on the specified SQL Server”. Please feel free to leave a comment below.