Same SSID an Different zones and VLAN

[pietro_fazio]

I have a Virtual SmartZone - High Scale (BLCluster) (version 3.4.0.0.976) and my actual configuration is the sequent:
I have 3 different ssid in 3 different AP Zones (For example Zone1, Zone2, Zone3)
My 3 SSID are "Office1" (Zone1 - vlan 100), "Office2" (Zone2 - vlan200), "Office3" (Zone3 - vlan300):
I need to creat a user that can connect on the 3 SSID and that, have to insert the username and the password (or just the same password only, it's the same);it could be good if the user has to  to reinsert username and password once per SSID.
I understand that the situation is really complex, but, can you tell me if is there a way, even if someone has some other ideas ?
Thanks a lot

[michael_brado]

It sounds like an external HotSpot WLAN might be what you're looking for.
You can use any RADIUS and require Username/Password login authentication.

[pietro_fazio]

Yes, and this could be a solution, I've yet read about it (I have also the possibility of 802.11x authentication). Just another question: if I create a user, named "myname" with password "pwd" and authentication radius, how can I make him connect on the three ssid with the same username and the same password ?
Thanks a lot again