This is what I want to do:
ISP's DSL router (LAN port) <-- ethernet cable --> (WAN port) Airport Express
(I know it's not possible to extend non Apple WiFi points wirelessly, so I need the ethernet cable).
Then I'd like the Express to extend the existing DSL network, using the same SSID, password and security type.
It sounds simple but I've burned most of a day trying every combination I can think of and I cannot get this working!
Can anyone offer step by step instructions on the setup required via the Airport Utility app please? :)
Note that each time I've tried a new combination I've factory reset the router (hold the reset for +5 seconds whilst powering it on) and have done multiple reboots of the DSL router.