We have successfully built wireless networks with IAP-215 (firmware 6.5.4.3) and everything have been working great. Guests can use external captive portal for authenticating with vouchers. We are using Hotspotsystem as external CP.
When we tried the same solution with IAP-315 (firmware 6.5.4.6) in a new office and same configuration, external captive portal doesn't work. After submitting the password in Internet browser, the URL changed to http://securelogin.arubanetworks.com/cgi-bin/login. It should start sending RADIUS-traffic after that, but nothing is send so there is something wrong about this internal CP securelogin.arubanetworks.com.
RADIUS ports (1812,1813) are opened in firewalls and tested. Is there something we could do or test? I looked up something about securelogin.hpe.com and certificates but I think they are not linked to this.