How to Open Ports in Windows?

How to open ports in the Windows operating system?

In Windows servers or personal computers, a port must be allowed through the firewall for an application to be accessible from an external network. By default, Windows keeps many ports closed for security reasons. Therefore, when running a service, the port used by that service must be manually opened through Windows Defender Firewall.

Why Opening a Port is Necessary

A service accepts incoming connections through a specific port. If the firewall blocks that port, external users will not be able to connect even if the service is running.

For example, port 25565 is commonly used by many game servers. If this port is blocked by the firewall, users will not be able to connect to the server.

Opening a Port Through Windows Firewall

Opening a port in Windows is done through the Windows Defender Firewall with Advanced Security interface.

First, open the Start menu and search for Windows Defender Firewall with Advanced Security to access the firewall management panel.

In the window that opens, go to the Inbound Rules section located on the left side. This section contains rules that control incoming connections from external networks.

Click New Rule on the right side to create a new rule.

Follow these steps in the rule creation wizard.

In the Rule Type section, select Port.

Choose either TCP or UDP depending on the protocol used by the service. Most services use TCP.

In the Specific Local Ports field, enter the port number you want to open. For example, you can use 25565.

In the next step, select Allow the connection. This setting allows the firewall to accept incoming connections on the specified port.

In the following screen, choose which network profiles the rule will apply to. Usually Domain, Private, and Public are all selected.

In the final step, give the rule a name. For example, Game Server Port 25565 can be used as a descriptive name.

After the rule is created, the specified port will be opened in the Windows firewall.

Checking Whether the Port is Open

Opening a firewall rule alone is not always enough for external access. There must also be an active service running on that port. If no service is listening on the port, port checking tools may still report it as closed.

You can verify the port status using the following methods:

Using online port checking tools
Testing the connection with Telnet or Netcat
Running the netstat -ano command on the server to see if the port is listening

Opening a port in Windows is done by creating an inbound rule through Windows Defender Firewall. Correctly selecting the port number, protocol type, and ensuring the related service is running are essential for allowing external connections. This configuration is especially important for services such as game servers, web servers, and remote access applications.