How Do I Open a Port on Windows Firewall? (2024)

Firewalls are there to protect you from threats on the internet (both traffic from the internet and from local applications trying to gain access when they shouldn't). Sometimes, though, you'll want to allow otherwise restricted traffic through your firewall. To do so, you'll have to open a port.

What Do Ports Do?

When a device connects to another device on a network (including the internet), it specifies a port number that lets the receiving device know how to handle the traffic. Where an IP address shows traffic how to get to a particular device on a network, the port number lets the receiving device know which program gets that traffic. By default, most unsolicited traffic from the internet is blocked by Windows Firewall. If you're running something like a game server, you might need to open a port to allow that specific kind of traffic through the firewall.

How to Open a Port on Windows 10

Clicking Start, type "Windows Firewall" into the search box, and then click on "Windows Defender Firewall."

Once Windows Firewall opens, click on "Advanced Settings."

This launches Windows Defender Firewall with Advanced Security. Click the "Inbound Rules" category on the left. In the far right pane, click the "New Rule" command.

If you need to open a rule for outgoing traffic, instead of clicking "Inbound Rule," you'd click "Outbound Rule." Most apps are pretty good about creating their own outbound rules when you install them, but you might occasionally run into one that cannot.

On the Rule Type page, select the "Port" option and then click "Next."

On the next screen, you'll have to choose whether the port you're opening uses the Transmission Control Protocol (TCP) or User Datagram Protocol (UDP). Unfortunately, we can't tell you specifically which to use because different apps use different protocols. Port numbers can range from 0-65535, with ports up to 1023 being reserved for privileged services. You can find an unofficial list of (most) TCP/UDP ports on the Wikipedia page, and you can also search for the app you're using. If you can't determine the specific protocol to use for your app, you can create two new inbound rules — one for TCP and one for UDP.

Select the "Specific Local Ports" option and then type the port number into the field provided. If you're opening more than one port, you can separate them by commas. If you need to open a range of ports, use a hyphen (-).

Click "Next" when you're done.

On the next page, click "Allow the Connection" and then click "Next."

Next, choose when the rule applies and click "Next." You can choose one or all of the following:

• Domain: When a PC is connected to a domain controller that Windows can authenticate access to the domain.
• Private: When a PC is connected to a private network, like a home network or a network that you trust.
• Public: When a PC is connected to an open network, like a cafe, airport, or library where anyone can join, and the security is unknown to you.

In the final window, give your new rule a name and an optional, more detailed description. Click "Finish" when you're done.

If you want to disable the rule at any point, locate it in the list of Inbound or Outbound Rules, right-click it, and then click "Disable Rule."

That's all there is to it. If you need to open any other ports for a different program or with a different rule, repeat the steps above using a different set of ports to open.