Not directly on the WLC, but using Cisco ACS, ISE or other RADIUS server, you can set the captive URL using the url-redirect value of the cisco-av-pair RADIUS attribute. This overrides the WLC default setting for External Webauth URL. You can also set the url-redirect-acl to match a named ACL on the WLC.
Based on this Configuration Guide, it would appear to only support one portal. I don't know if there's a way to specify the SSID (network) to the portal page / WLC. (I've never needed to. [it's in the wlan query param])
Update: Apparently 7.3+ can, but it's a lot more involved. "Assigning Login, Login Failure, and Logout Pages per WLAN"
Regarding question 1 on mobile device licensing
Per your comment below, I did a couple tests on our ASA5525-X which has Essentials/Mobile licenses. I was indeed able to limit access using Dynamic Access Policies. I setup a test policy allowing only iOS devices on iPad2,7 models to connect in a new policy. Then I setup the default policy to terminate ...
You could use PKI in your authentication which would require assigning certs to devices. This is covered under the AnyConnect Essentials license. One thing to note, I have never gotten any ASA to accept any certs encrypted with higher than 2048 bits. This may have changed in releases newer than 9.1.2 though.
A more in depth option would be using the Host ...
There is no 100% definitive method other than actually finding the thing, but there are various clues.
What is the vendor in it's MAC address? what does that vendor make?
Where is it connecting to? lots of public websites? (implies someone or something browsing the web) lots of IPs in dynamic ISP space? (implies peer to peer activity) a small handful of ...
So my question is how can i positivity identify the example above are
in fact android devices.
Bottom line: you can't, especially given the restrictions you mention in @petergreen 's answer. The best you can do is make an educated guess. Depending on your goal, a guess may be good enough answer. Don't let the quest for perfection stop you from doing ...
This is just a guess, but wouldn't a non-proprietary solution (perhaps the mobile version of something like OpenVPN) be a possible solution?
While some mobile phone OSes (Palm OS, etc.) do not support OpenVPN,
it is available for Maemo, Windows Mobile 6.5 and below, iOS
3GS+ devices, jailbroken iOS 3.1.2+ devices, Android 4.0+