Create an Outbound Port Rule

By default, Windows Defender Firewall allows all outbound network traffic unless it matches a rule that prohibits the traffic. To block outbound network traffic on a specified TCP or UDP port number, use the Windows Defender Firewall with Advanced Security node in the Group Policy Management console to create firewall rules. This type of rule blocks any outbound network traffic that matches the specified TCP or UDP port numbers.

Administrative credentials

To complete these procedures, you must be a member of the Domain Administrators group, or otherwise be delegated permissions to modify the GPOs.

To create an outbound port rule

  1. Open the Group Policy Management Console to Windows Defender Firewall with Advanced Security.

  2. In the navigation pane, click Outbound Rules.

  3. Click Action, and then click New rule.

  4. On the Rule Type page of the New Outbound Rule wizard, click Custom, and then click Next.

    Note:  Although you can create rules by selecting Program or Port, those choices limit the number of pages presented by the wizard. If you select Custom, you see all of the pages, and have the most flexibility in creating your rules.

  5. On the Program page, click All programs, and then click Next.

  6. On the Protocol and Ports page, select the protocol type that you want to block. To restrict the rule to a specified port number, you must select either TCP or UDP. Because this rule is an outbound rule, you typically configure only the remote port number.

    If you select another protocol, then only packets whose protocol field in the IP header matches this rule are blocked by Windows Defender Firewall. Network traffic for protocols is allowed as long as other rules that match don't block it.

    To select a protocol by its number, select Custom from the list, and then type the number in the Protocol number box.

    When you've configured the protocols and ports, click Next.

  7. On the Scope page, you can specify that the rule applies only to network traffic to or from the IP addresses entered on this page. Configure as appropriate for your design, and then click Next.

  8. On the Action page, select Block the connection, and then click Next.

  9. On the Profile page, select the network location types to which this rule applies, and then click Next.

  10. On the Name page, type a name and description for your rule, and then click Finish.