AirPort Extreme as a bridge
QWe have an AirPort Extreme 802.11ac connected to our Uverse router. Since I set up the AirPort, it reports ’Setup over WAN’ and ’Double NAT’. Our old AirPort Extreme worked fine in Bridge mode, but when I try that with our new one, including turning DHCP off, it blocks Wi-Fi access. Are those status reports acceptable?
AYou’re correct: in your setup, a Wi-Fi base station should operate in Bridge mode, and shouldn’t serve DHCP, as your Uverse router does that. You can turn the DHCP server off and set it to use a fixed IP address from a static block allocated on your router, but that can be fiddly. The consumer solution is the ’Double NAT’ scheme which your new AirPort Extreme uses to work around having two DHCP servers active. It only becomes a nuisance if you need to use IP addresses to trace a network problem.
You should also disable the feature to permit setup over WAN, as that could allow an intruder to take control of the network. However, as your AirPort base station lives inside your router’s firewall, provided that’s configured to block all incoming connections, there is no real risk.
The purist dislikes this approach, but if it works well, it’s wise to leave it alone.