How to open a port in Microsoft Defender Firewall
14/10/2025If you are using a different firewall, the following instructions may not apply.
Port 27027 will be used as an example for instructional demonstration, the same procedure can be applied to all blocked ports.
Step 1: To open a port in Microsoft Defender Firewall, go to your PC Start menu and type Run in the search bar.
Step 2: Type WF.msc, and then click OK.
Step 3: In the Windows Firewall with Advanced Security, in the left pane, Inbound Rules, and then click New Rule in the action panel.
Step 4: In the Rule Type dialog box, select Port, and then click Next.
Step 5: Select TCP and Type in 27027 in the specific local port field, then click Next.
Step 6: Select Allow the connection, and then click Next.
Step 7: Apply the rule to all 3 options (Domain, Private, and Public), and click Next.
Step 8: In the Name dialog box, type “3Shape Dongle Server Service” and add a description for this rule, and then click Finish.
Step 9: To create an Outbound Rule, return to step 3 and select Outbound Rules in the left panel. Proceed to follow steps 4-8.
If this does not resolve the issue, a firewall on the network itself may be causing the problem.
How to check if the port is open with netstat
Step 1: Open Command Prompt by pressing Win + R, type cmd, and press Enter.
Step 2: In the Command Prompt window, type the following command and press Enter: netstat -an | find "PORT" (replace PORT with the port number you want to check).
Step 3: Look for lines that include the port number in the "Local Address" column. If the port is open and listening, it should appear as 0.0.0.0:PORT or ::PORT with the status “LISTENING.”
Step 4: Close Command Prompt. This process helps determine if the port is open and being used by any application on your local machine.
Contact 3Shape Support if you have any further questions.