This is the situation.
I have a client with an Aruba controller 620 in his main office. They have two WLAN in that controller, for employees and for guest users. We are using a customized captive portal uploaded to the controller for guest users.
This client have several remote office, connect by VPN, and they want to use Aruba Instant in those offices. (they don't use RAP's for two thing; save money in Aruba Controller licenses, and Aruba controller model 620 have reach maximum AP+RAP capacity).
So, in this deployment, for employees we will configure an employee WLAN with internal user authentication. No problem with that.
Main problem is guest network, because Aruba Instant Internal captive portal is not customizable (and, for be honest, ugly as hell).
I have been trying using VPN connection between Instant and Aruba controller, adding route 0.0.0.0 0.0.0.0 to Aruba Controller, and using guest access rol for IAP VPN but is not working (I read somewhere that this is not possible with Aruba Controller 620 because a lack of memory).
Next thing i tried is what i opened the post for: use Aruba controler as Aruba Instant external captive portal, but it doesn't work..
So, at this point, I don't know what to do... :