PPPoE

The FireBrick 2700 supports PPPoE - so you can use it to connect via a modem, eg a:

FTTC Modem
A standard issue AAISP ZyXEL P660-D1, in bridge mode
Another modem set for bridge mode
A modem such as a TP-Line or Draytek

Example XML Configuration (now deprecated, as ppp config now in top level)

   <port name="PPPoE" ports="1"/>
   <interface name="PPPoE" port="PPPoE">
      <ppp username="abc@a.1" password="secret" mtu="1492" graph="AAISP ADSL"/>
   </interface>

Herewe are using the first ethernet port as the one connected to the modem... We had also set up the other 3 ports as the LAN. More details in the FireBrick documentation.

Native IPv6

Assuming you have an IPv6 block allocated to your line on Clueless and you're using the FB for PPPoE, then all the FB config needs is:

An IPv6 address on the LAN subnet
ra="true" in the subnet

Your computers should then get IPv6 details. test on http://ip.help.me.uk