Network access control

How to open firewall port on Windows 10

If you have an app getting blocked by the firewall, here are the steps to open the port through the Microsoft Defender Firewall on Windows 10.

Opening a firewall port on Windows 10

On Windows 10, the built-in firewall (also known as the “Microsoft Defender Firewall”) is a powerful feature that has been designed to protect your device and data from different threats from outside trying to get in as well as threats from inside trying to get out.

A firewall basically works as a gatekeeper and blocks all unnecessary network ports, and every time an app or service tries to communicate outside your device, it checks if there’s a specific rule in the database to allow or deny network access. If it can’t find a rule, you’ll see a prompt to identify and grant or deny permission.

Sometimes well-known applications (for example, SQL Server and QuickBooks) will not work properly because they’re getting blocked by the Microsoft Defender Firewall. When this happens you’ll need to create a rule to allow them access to the network manually.

In this guide, you’ll learn the steps to open a port to allow an app to communicate outside of the network using the built-in firewall on Windows 10.

Open firewall port on Windows 10

If you’re using the Microsoft Defender Firewall, and an app requires one or more ports open in order to operate, use these steps:

Important: Before proceeding, check the app support documentation to know the ports and protocol type you need to open. Also, you can quickly confirm if you need to open a port by temporarily disabling the firewall, and if the app works with the firewall disabled, then it indicates you need to create a new rule.
  1. Open Windows Security.

  2. Click on Firewall & network protection.

  3. Click the Advanced settings option.

    Firewall advanced settings option
    Firewall advanced settings option
  4. Select Inbound Rules from the left navigation pane.

  5. Under the “Actions” section, in the right pane, click the New Rule option.

    Windows Defender firewall Inbound rules
    Windows Defender firewall Inbound rules
  6. Select the Port option.

    Firewall open inbound port option
    Firewall open inbound port option
  7. Click the Next button.

  8. Select the appropriate protocol (TCP or UDP) depending on the application. (Usually, the option is TCP.)

  9. In the Specific local ports field, type the port number.

    Open specific firewall port using TCP or UDP protocol
    Open specific firewall port using TCP or UDP protocol
    Quick note: If the app requires multiple ports open, you can type as many as you need as long as you separate each one with a comma (4500,4600,5000). In the case that you need to specify a port range, then you can use a hyphen (-). For example, 3000-3100.
  10. Click the Next button.

  11. Select the Allow the connection option. (Using the same step, note that you can also block connection.)

    Allow connection settings
    Allow connection settings
  12. Click the Next button.

  13. Select the network type to apply the rule. (Usually, you want to leave this option with the default selections.)

    Firewall network profile settings
    Firewall network profile settings
  14. Click the Next button.

  15. Type a descriptive name for the rule. For example, My Inbound Rule for QuickBooks.

    Firewall open port rule name settings
    Firewall open port rule name settings
  16. Click the Finish button.

After you complete the steps, inbound connections will be allowed for the app through the port you open in the firewall.

Open outgoing port in Microsoft Defender Firewall

In the case that the app needs a specific outbound port, you can use the same instructions, but instead of selecting Inbound Rules on step No. 4, you would choose the Outbound Rules options. Here’s how:

  1. Open Windows Security.

  2. Click on Firewall & network protection.

  3. Click the Advanced settings option.

    Firewall advanced settings option
    Firewall advanced settings option
  4. Select Outbound Rules from the left navigation pane.

    Firewall outbound rules
    Firewall outbound rules
  5. Under the “Actions” section, in the right pane, click the New Rule option.

  6. Select the Port option.

    Firewall open outbound port option
    Firewall open outbound port option
  7. Click the Next button.

  8. Select the appropriate protocol (TCP or UDP) depending on the application.

    Firewall outbound protocol option
    Firewall outbound protocol option
  9. In the Specific local ports field, type the port number.

  10. Click the Next button.

  11. Select the Allow the connection option.

    Allow outbound connection
    Allow outbound connection
  12. Click the Next button.

  13. Select the network type to apply the new rule.

  14. Click the Next button.

  15. Type a descriptive name for the rule.

  16. Click the Finish button.

Once you complete the steps, outbound connections will be allowed for your application through the port you open in the firewall.

Close firewall port on Windows 10

To close the port in the Microsoft Defender Firewall, use these steps:

  1. Open Windows Security.

  2. Click on Firewall & network protection.

  3. Click the Advanced settings option.

    Firewall advanced settings option
    Firewall advanced settings option
  4. Select Inbound Rules or Outbound Rules from the left navigation pane depending where you open the firewall port.

  5. Select the rule you want.

  6. Under the “Actions” section, click the Disable Rule to close the port while keeping the rule. Or click the Delete rule to close the port and remote the rule from the firewall.

    Disable or delete firewall rule
    Disable or delete firewall rule

After you complete the steps, the app or service will no longer have access to the network or internet.

If you’re having issues configuring your firewall, you can submit your questions in the Pureinfotech forums.