I have been using the present setup with WLC2106 and 2 LAPs. So far the management and ap-manager interface where on the same subnet (192.168.0.x). I was using a static IP address for the wireless clients, also on the 192.168.0.x. So far so good and everything was up and running. Now I wanted to the wireless clients to get an IP address from the DHCP server on the 192.168.0.x subnet. The IP addresses leased will be on a different network - 192.168.7.x. I tried changing the ap-manager to and IP address on the .7.x network and set DHCP server on both interfaces. However, I cannot the clients are not being associated, and when I try and give an IP addresses statically on the .7.x network, I cannot ping anything from the clients. Routing is not the problem as I have confirmed that this is working ok.
Should I change the management interface (as the WLAN is associated with this interface, and I cannot choose the ap-manager)? Or should I use a dynamic interface?
In order to drop clients onto a different subnet/VLAN other than on your AP-Manager and Management interfaces, you'll need to deploy a new dynamic interface on the WLC. Also be sure the trunk over the new vlan to the WLC. Here's a great guide that explains how to accomplish this one.
VLANs on Wireless LAN Controllers Configuration Example
Hope this helps.