Airport extreme n not connecting to the internet but green light is on

Question

Original configuration worked until a few days ago like this... Cable modem (RCA Digital by Comcast Model DHg535-2) ran into airport extreme N... into a D-Link DGS-2208 8 port switch... off to 8 different macs / printers/apple tv's/ and wireless macbook pro. Perfect.
Dilemma now. Cable modem running direct to main IMAC and works fine connecting through DHCP and active ip address. Ethernet shows green light in system preferences and connected. Unhook the line to the Mac and into the airport. Airport lights up green, bars show as connected, my original apple network is showing and connected w green light on airport and in system network preferences. Once this is done i can not access internet pages and they just spin on "loading". Hardline from airport extreme is connected to the IMAC and still no internet. Wireless shows up on macbook but still states "Loading".
Step one - connect to internet through direct line cable model. WORKS
Step two - connect to internet through direct wire through model/airport. No
Step three - connect through wireless - No
Step four - reestablish my switch and get everything back on line - Nope.
Bunce

Answer 1

The problem may be when you switch what is connected to the modem by just unplugging and replugging devices.
Any time you change network configuration, you should perform a complete power recycle of all of the network equipment to make sure that they are both "recognized" and initialized properly.
Please try the following:
o Power-down the modem, 802.11n AirPort Extreme Base Station (AEBSn), D-Link switch, & computer(s)/printer(s). Wait at least 10-15 minutes. Order is not critical.
o While the power is off, reconfigure your network to include the AEBSn.
o Power-on the modem; wait at least 10-15 minutes.
o Power-on the AEBSn; wait at least 5-10 minutes.
o Power-on the D-Link switch; wait at least 5 minutes.
o Power-on the computers/printers.