You can use AirPort Utility to adjust IPv6 firewall settings if your base station supports IPv6. You can also use AirPort Utility to adjust IPv6 firewall settings on a Time Capsule.
Open AirPort Utility, located in the Utilities folder in the Applications folder on a Mac, and in Start > All Programs > AirPort on a Windows computer.
Select the device you want to adjust, and then click Manual Setup. Enter the password if necessary.
Click Advanced in the toolbar, and then click IPv6 Firewall.
By default, “Allow Teredo tunnels” and “Allow IPSec authentication” are selected.
To provide access to specific devices on your network from outside the IPv6 firewall, click the Add (+) button and then enter the IPv6 address or the port for the device.
To use an IPv6 firewall, you need an AirPort Extreme 802.11n Base Station with firmware version 7.2 or later, or a Time Capsule.
Check the AirPort support site for the latest base station firmware.