WiFi connected but network not reachable? Reboot the access point

I recently dealt with a computer that couldn't reach the network while connected to a WiFi network. All the other machines around were working perfectly fine, but this one couldn't even get an address from DHCP. Rebooting and resetting the WiFi adapter did nothing. Eventually, I logged on to the web management panel of the Linksys LAPN600 access point to check for connections. The machine was there, and all access point settings looked right. I noticed that the device wanted a firmware update, so I had it install that, and in the process it rebooted. When it came back up, the problem was fixed. I'm not sure exactly what happens to APs after long uptimes, but apparently sometimes reboots are helpful.