In addition to working as a conventional LNS, the FireBrick can also be configured to operate as a PPPoE endpoint as a BRAS. The PPPoE connections appear as if they has arrived via L2TP, so can have local IP termination or relay via L2TP to another LNS.

The FireBrick supports baby jumbo frame negotiation to allow full 1500 byte MTU operation.

If an interface is configured to work in PPPoE BRAS mode, then it can accept packets with an additional VLAN tag. This is passed as the NAS_PORT on RADIUS requests relating to the connection. The reply packets have the same VLAN tag added. Where the interface is set up on VLAN 0 (untagged) then the additional VLAN tag is only processed where there is not an interface or ppp setting for that specific VLAN configured.