Airport Extreme, PPPoE and fixed IPv6

Hi, My ISP gives me an entire /48 Ipv6 Subnet over my ADSL Line. In the past I had a ADSL modem configured in bridge mode connected to a FreeBSD box. So the FreeBSD box autoconfigurated all my combuters with the ratd daemon.

But recently I studied the Airport Extreme manual and discovered that the device support PPPoE and in the Advanced pane there is an option for IPv6 to configure as a node.

But the Airport Extreme doesn't configure with my subnet. Have somebody a solution?

Sincerely

Kevin