Aiport Extreme to extend network - issues

[cperry]

I have ATT Uverse internet. We have an old house iwth plaster walls and need extenderes. About 1.5-2 years ago I got the 2 expresses. Then the internet lagged a lot. ATT kept denying. So about 1 yr ago got an airport extreme and set it up. Helped a little bit. Finally got ATT out and got a new faster modem. As I reset up the network I get conflicts (think it was the extreme). The ATT network works great but again need the extenders. So I reset all devices (factory) and just added the expresses with the "extend a network choice". Works great. Now want to add the extreme in but as a network extender (like the expresses) not a new network or replace a network. It will not - even though I have the choices - it just pops back to create a new network. I have resetna dn restarted everything and same thing. I am not too techy but get basics.
Thoughts?
Thanks

 

[Altemose]

Now want to add the extreme in but as a network extender (like the expresses) not a new network or replace a network. It will not - even though I have the choices - it just pops back to create a new network. I have resetna dn restarted everything and same thing.

An AirPort can only wirelessly extend another AirPort's network.

 

[cperry]

An AirPort can only wirelessly extend another AirPort's network.

Sorry that does not make sense to me. There are three options for set up..... Create a new network, replace an exisiting network or extend a network. The expresses let me select extend a network and the extreme show the options but does not let me select extend a network it just defaults back to create a new network after I select the radio button for extend a network..., off of my AT&T modem.

 

[Altemose]

Sorry that does not make sense to me. There are three options for set up..... Create a new network, replace an exisiting network or extend a network. The expresses let me select extend a network and the extreme show the options but does not let me select extend a network it just defaults back to create a new network after I select the radio button for extend a network..., off of my AT&T modem.

The Expresses are not supposed to be showing that option at all and I am surprised that they do. What I would do is set the AT&T modem into bridge mode and use the Extreme as the router. Then extend the Expresses off of that.