I have an Airport Extreme (4th generation) with firmware 7.5.2; it has been working fine for a long time, but stopped working properly after a brief power outage a couple of days ago.
The router powers up normally and shows a solid green light, alas connected devices (a notebook, apple tv, and a couple of iphones) get "no internet".
using the Airport Utility i have verified that the WAN link is up and the devices are accociated with the network; I have also called the ISP and verified that the IP lease is ok.
I have tried resetting the router several times, as well as powering down different elements of the network and restarting them in different order.
i should mention also that my service is over a fiber network, so if I plug the Ethernet cable directly into my notebook everything works fine - the ISP is not to blame.
To me this seems to be a problem with the Airport router itself, a software / firmware problem of some sort - has anyone come accross anything similar?