If you have CCKM enabled, that's going to cause problems. It's recommend only on WLANs where you have very tight control of the clients, and a college SSID with students connected is not one of them. There are a lot of client drivers that can't deal with it, and they will roll over on a roam, be it to another AP or from 2.4 to 5. Just say no to that feature.
CCKM is however really helpful with VoIP roaming, so we use it only in a WLAN dedicated to our Cisco VoIP phones - huge difference there, and the phones all support CCKM. Band select and load balancing - trouble makers (I see it both on Cisco and Aruba's version). There are enough client driver oddities, and you'll be forever chasing your tail. We don't have them enabled, and distribution between 2.4 and 5 looks great. We have a dense deployment, so load balancing has so far been unnecessary i.e. less than 10 devices per AP, split between radios. Jeff >>> On Wednesday, October 01, 2014 at 4:10 PM, in message <[email protected]>, "Ashfield, Matt (NBCC)" <[email protected]> wrote: Hello We are seeing some intermittent issues with some of our student computers (a lot of HPs, but some others) whereby they will be working away, well connected, and suddenly get the yellow exclamation mark in on their wifi connection in the taskbar and lose connectivity. Sometimes they can get back on, sometimes they have to reboot. We have tried updating drivers and that has not fixed the problem, although in one case we forced the client to 2.4ghz range thru settings in the adapter and that seemed to fix the probem in some cases. The issue is very odd. It appears almost to be location or AP specific although reports are hard to nail down. Anecdotal reports suggest more difficulty with non-3702i APs (we have some 3500's and 3600's APs as well) The network is an EAP-TLS network with client side certs. As with most student wifi issues, it’s nearly impossible to get real debugging results, but one thing we have noticed is when the student is having issues, we’ve seen where the controller is showing them as associated and authenticated, but the client machine seems to show that it has an IP gateway and mask but for some reason there’s no gateway entry in the ARP table of the client. Release/Renew does nothing. Ping from the gateway does nothing. Very odd issue. DHCP is provisioned by a central Microsoft DHCP server (ie, not the cisco device) and we’re using 1 hour lease times. Some students we've seen it happen to are a result of their laptop going asleep. I personally tend to lean towards this being a client driver issue. Problem is, it's nearly impossible to have every student with up to date drivers in this BYOD type world we operate in. At the end of the day, we have students who need wifi access and cannot get on and blaming IT. This is a small subset of users, but an issue nonetheless. I have heard rumblings of various wlc options/settings that may be causing issues and we do have the following list below. Turning one off at a time is an option I suppose, but hoping that someone may have some better recommendations here. - Client Band Select enabled - Client Load Balancing enabled - User Idle Timeout set to 5400 Seconds (this is under Controller/General) - CCKM enabled - Session Timeout 36000 (this is under WLAN/Advanced) - DHCP Address Assignment Required is checked Any advice/info is appreciated. Thanks Matt ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
