Client Exclusion Policies on WLC not working with ISE as RADIUS Server

Question

Hi,
for our Guest WLAN (Security Setting for this SSID:Layer2: MAC filtering, Layer3:none) we use ISE as RADIUS Server. On WLC I enabled client exclusion polices and checked all options (Excessive 802.11 Auth. Failures etc..).. But even if a client fails 20times at authentication, it is not excluded on the wlc. It works with other SSIDs, where security settings are set to 802.1x.
Am I missing any settings here or do you have some tipps on how to troubleshoot this?
Thanks very much!

Answer 1

Hi Renata,
If those guest failures are not associated with valid guest users (i.e. people who have forgotten their account or entering the wrong password) there isn't anything that can be done. The main point of Guest WLAN is to make it as easy as possible for Guests - individuals with device configurations you don't want to deal with or know about, to connect your network for internet access. From a WiFi/802.11 perspective, the standard Guest WLAN setup means its easy for any device to connect.
If your Guest WLAN has the following:
SSID is broadcast enabled, Security = OPEN, Encryption = none, then any 802.11 device can find the WLAN via passive scanning and connect. And any device that connects will get the ISE portal. Once recieveing that portal they can guess away at valid username/password.
I would suspect that unless your Guest WiFi is adjacent to a Mall, school, hotel or other hi-density area of individuals  with time and electronics on their hands, other than alerts in your ops window and logs, resources associated with this (WLC & ISE) are very low.
You can try and dull the noise a few ways.
Option 1. create and ISE log filter on those alerts so they don't cluter the console.
Option 2. Stop broadcasting the SSID.  This is not a security measure, but will cut volume of people connecting to the SSID significantly. You will have to tell your guests what SSID or include it in their credential communication.
Option 3. Put a very simple PSK on the SSID. The PSK will become a public secret - shared with valid guests, doesn't have change as it's purpose is not security.  You will have to include this information on their credential communication.
Option 4 - both 2 and 3
The most effective option would be 3.
Good Luck!