I'm still using the original comcast modem since it has a WAN/LAN port. But the new router/modem, that they arbitrarily sent to me, has no WAN/LAN port. I definitely prefer to use the Airport Extreme, especially since I have an external drive connected for Time Capsule. SOLVED: 1. Put comcast router/modem into Bridged Mode. 2. Connect airport extreme to PORT 1 on the comcast machine (this is now "the WAN port"). 3. This third part is key: restart the COMCAST MACHINE That's right sports fans. You have to do the Windows Solution (restart your computer) to get the Airport Extreme and comcast machine to recognize each other. I had tried restarting the AE several times to no avail. I had gone through all the fields on both machines, researched IPv6, ad infinitum. DON'T NEED TO CHANGE NOTHING on EITHER machine. Just do the three items listed above.