You can. When creating the Guest SSID set the "Primary Usage" as Guest. When this is done the SSID defaults the IP assignment to "Virtual Controller Assigned".
The IAP uses a default scope for IP assignment, however, you can change the scope. To change the scope click "Settings" link in the upper right corner of the screen, Next, click "Show Advanced Options" and you will see a "DHCP" tab appear. NOTE: we added this feature in later releases of code so you might need to upgrade to get this feature.
To download the Users Guide go to our TAC site and look under documentation > SW Users Guides > Instant.
Or click here....