We have had a 4th gen Airport Extreme for 4 years now. We recently moved into a bigger home and are not getting a good wifi signal on the 2nd floor of the house. So I just went ahead and bought the latest 6th generation Airport Extreme (802.11ac). Now, I would like to connect the new Extreme to the cable modem to create our wifi network and place our existing older Extreme on the 2nd floor to extend the network. Is there anyway I can use the same network name and password (that we have used for years) for the new Extreme while changing the old Extreme from being the 'main router' to a 'wifi extender'? This will help me from having to reenter the network name and password on all our devices. If this possible, how would I go about doing this?