I've had a D-Link DI-604 4-port LAN 1-port WAN ethernet router since 2003 which has allowed all of the wired computers in the house access to the internet (I have broadband via a cable modem). I recently introduced an AirPort Express router which I connected to one of the LAN ports on the D-Link and I now have wireless internet access on my MBP with no problems. However I plan to also purchase an AirPort Extreme router to make use of its AirDisk feature and improve wifi reception in the house. From a security perspective, I am wondering if it would be more secure to connect the WAN port on the Extreme to one of the LAN ports on the D-Link, thus in theory being protected by 2 different hardware firewalls? Or does this not make any difference, in which case I should simply replace the D-Link with the AirPort Extreme?