How to Allow Traffic to Come Through My Apple Router

Servers and games often require incoming network traffic.

Apple AirPort Extreme routers include a built-in firewall that blocks all incoming network traffic. The Apple router shares a single IP address on the Internet among one or more devices on your local network. When a computer tries to connect to your external IP address over the Internet, the AirPort Extreme doesn’t know what computer to send the connection to and discards the incoming traffic. You can allow traffic to come through the router by setting up port mapping, which tells the Apple router where to send the traffic.

Instructions

1. Set a fixed IP address on the computer you want to allow traffic for. Open the Network pane in the System Preferences window on your Mac, click the “Show” menu and select “AirPort,” click the “Configure IPv4” menu, select “Manually” and enter an IP address for the computer.

2. Open the AirPort Utility. Click “Applications” in the Finder on your Mac, double-click the “Utilities” folder and double-click the “AirPort Utility” icon.

3. Select your Apple AirPort Extreme router in the list and click “Configure.”

4. Click “Show All Settings” and click the “Port Mapping” tab.

5. Click the “Add” button to add a new port-mapping rule.

6. Type the fixed IP address of your computer into the “Private IP Address” box.

7. Type the port of the traffic you want to allow into the “Public Port” and “Private Port” boxes. Use the same port number on both boxes unless you have a specific reason to do otherwise. Consult the software’s documentation for the port it requires.

8. Click the “Update” button.

Tips & Warnings

• You can also allow all traffic to come through your Apple router and go to a specific computer. Click “Base Station Options” after clicking “Show All Settings,” enable the “Enable Default Host At” check box and enter the computer’s IP address. This exposes the computer to the Internet and can make the computer vulnerable to attack.

• Set a fixed IP address on Windows by opening the Network and Sharing Center in the Control Panel, clicking the name of your connection, clicking “Properties,” selecting “Internet Protocol Version 4 (TCP/IPv4)” in the list, clicking “Properties,” clicking “Use the Following IP Address” and entering an IP address.

• Open the AirPort Utility on Windows by clicking “Start,” clicking “All Programs,” selecting the “AirPort” folder and clicking “AirPort Utility.”

References

• Apple: AirPort Extreme Setup Guide [PDF]
• Apple: Designing AirPort Extreme Networks [PDF]