We're seeing a very similiar problem with our free internet offering for our customers. We're running aOS 5.0.4.1.
The issue has been seen on Android versions 2.3.5, 4.0.3 and 4.1.1
We are seeing a number of reports from our stores that have been replicated on our test environment here at our office that Android phones are not able to use our customer WiFI, the symptoms are that the captive portal (we use an AmigoPOD) takes a noticeably longer time to load and after entering the customer’s details on the portal page the redirect that is part of the registration fails (server time out) and the Android phone is unable to get any further.
During testing at the office I found that if the Android phone is restarted before the attempt to connect is made the connection works the first time but subsequent attempts to reconnect (after deleting the user and attempting to re-authenticate via the captive portal) always fail. On investigation it seems that at this point, for some reason I do not understand that in many cases the Android client has two IP addresses, one of the IP addresses being valid and within the DHCP scope offered by the Aruba controller, the 2nd IP address invariably being outside of the scope. (note the restart fixing the issue for the first connect was only seen on my phone, I did not have the oppurtunity to restart my colleague's android phones I borrowed for a quick test)
show user-table (I've changed the MAC addresses to try and protect the innocent and not so innocent testers ;) )
10.88.252.230 1c:b0:94:4b:73:5f service-guest-logon-tnl 00:00:01 5300_Test Wireless Free Internet/00:24:6d:45:c9:11/g service-guest-tnl tunnel
10.167.253.63 1c:b0:94:4b:73:5f service-guest-logon-tnl 00:00:01 5300_Test Wireless Free Internet/00:24:6d:45:c9:11/g service-guest-tnl tunnel
10.88.253.14 18:87:96:83:12:aa service-guest-logon-tnl 00:00:03 5300_Test Wireless Free Internet/00:24:6d:45:c9:11/g service-guest-tnl tunnel
10.88.253.221 b4:07:f9:c9:3b:3c service-guest-logon-tnl 00:00:06 5300_Test Wireless
Free Internet/00:24:6d:45:c9:11/g service-guest-tnl tunnel
client 1c:b0:94:4b:73:5f has two IP addresses, 10.167.253.63 is outside the scope of the DHCP pool on the controller and 10.88.252.63 which is a valid IP address in the DHCP scope.
Regards
Nigel Brodt-Savage