Help! airport extreme won't recognize and extend my network

Question

OK - so I have a house with 3 floors - and was having trouble getting a good enough signal from my ground to my top floor. So I bought an airport extreme - and this was my plan.
1) To have the signal coming into my router (provided by my cable service) all on the ground floor.
2) To use a netgear 'booster' through a power socket, to take the signal to the first floor and hook this into an airport extreme.
3) Then to have another netgear booster on the top floor into an airport express so I could use airplay etc in my room on the top floor.
I want one single network to run within the entire house.
However, the airport extreme box - when I ask it to 'extend a network' - does not recognize the ethernet cable going into the back of it - even though i know there is a signal because it will allow me to 'create a new network' and it sees every other wifi signal for miles around, but does not recognize the signal coming out of the netgear booster and going into the back of it.
So now, I've got three different networks running in the house - one for each floor - and it's  a little frustrating....
thoughts on a postcard?

Answer 1

All that you need to do is insure that all 3 networks have exactly the same wireless network name, use exactly the same wireless security setting, and the same password. Then everything will behave as one "big" single network.
If your devices are capable, they will automatically "switch" to the access point with the strongest signal as you walk them around the house.
The AirPort Extreme and AirPort Express both need to be in Bridge Mode (they probably are), but you need to check on this as the last item before you update the settings.
The tricky part of this is the wireless security setting.....because you must know exactly what type of wireless security setting your cable service modem/router is using to provide the exact same setting to the AirPorts. I assume that you know the name of the "main" wireless network and password.
The AirPorts use WPA2 Personal by default, so check and see if your modem/router is using that setting. If not, you will need to change the modem/router to either WPA2 Personal (preferred) or WPA/WPA2 Personal (next best setting).  If you change the modem/router to WPA/WPA2 Personal, then you must also change it to the same setting on the AirPorts.
If the security settings do not match up exactly on all wireless access points, then the network will not behave as one "big" single network.
The settings for both AirPorts should look like this: