I have 2 sites with 2 IOS AP's each. I would like to use a WLC to control all 4 AP's. I want to have the same SSID at both sites, but have 2 different DHCP servers, one for each site.

The reason that made me think this might be possible is that I have several sites today with their own WLC's and when one WLC failed the AP's from that site immediately connected to a WLC at another site and the users continued getting site appropriate DHCP addresses. Not sure how that happened. I realize the AP's did not have to restart, they just connected to a new WLC at a different site. Hope that is clear.