I've seen several past discussions (can't seem to locate the correct key term to find the posts again) about the importance of the "HTTP Get URL" that is generated from the redirect (mac, ip, user-name, access-point, original website, etc). I'm trying to understand more of the importance of it and what's actually occuring if the information happens to be absent due to the user navigating away and returning later.
Brief Background
--ArubaOS 6.5.0.4 Controllers with Clearpass as External Captive Portal)--
We just recently consolidated our open SSIDs into a single SSID to serve three purposes (guest access, setup access, and non-802.1x-streaming access) with Clearpass returning a role for guest and non-802.1x -> this is working wonderfully. The issue we ran into was setting the redirect to a web page with three links to choose an option they wanted to use (guest, setup, streaming) - *what we discovered was the URL information was getting stripped and causing issues (I was absent that week). We got around this by have clients redirected to the "Guest Login" page that preserves the URL information - which also contain two additional links to either setup your 802.1x device or to register a streaming device.
The one behavior I've seen during my test was if I happen to hit the captive-portal with the URL information stripped (Either Bad Password - or Request an Account) -> if I submit my guest credentials -> I will get stuck on the "certificate-CN" with a blank page but I do pass authentication -> which I believe makes sense since Clearpass/Controller is missing the original site i was redirected from --> However, if I navigate to any website - it appears I have no issues accessing the internet.