Client connection issue after update WLCs to 8.10

[Heiko Kelling]

Hello wireless community,

we have 4 small locations, each with a Cisco 3504 controller and 15-20 x 1832I APs each, plus another bigger location with a vWLC and about 80 x 1832I APs. So far the firmware 8.9.100 was used and everything ran smoothly without any complaints. We have now updated a site with 3504 to version 8.10.171 and users were complaining about problems connecting to the WLAN. There are 3 SSIDs at all locations, which bridge into separate Vlans via Flex Connect. We then investigated the problem and it is indeed the case that numerous devices from different manufacturers cannot connect to the SSIDs (WPA2 auth). Some devices rarely come into the WLAN. Then we did a downgrade and everything went great again as before. Later we also have the update on the vWLC from 8.9.100 to 8.10.171 at the bigger location. Same problem! Then tested with various other 8.10. versions. Same problem. So downgrade, everything ok again. Then tested an 8.8, everything was ok.

In summary: 8.8 > good; 8.9 > good; 8.10 bad

Has anyone had similar experiences? It is a very simple structure (Flex Connect, WPA2). What changed in 8.10 that can create such a fundamental problem?

[marce1000]

       - FYI : https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwd37092

 Check this article too : https://community.cisco.com/t5/wireless-mobility-knowledge-base/aireos-8-10mr8-escalation-special/ta-p/4715772

   Resolved in : https://software.cisco.com/download/specialrelease/53112f47f8edc7e11a26a8c0580915fa

 M.

 M.

[Heiko Kelling]

Hello marce1000,

I´m not sure if this is really our issue, because we have it with all 8.10 versions. 8.10.181 we have not tested, only 8.10.171 and older 8.10 versions. tcp-adjust-mss size 1250 is already set. We don´t use 802.1X, only WPA2.

[marce1000]

 - I was a bit in doubt too  ,but I gave that information because at  a certain point you said 8.10.x is bad; I would have the configuration of a or the controllers checked with https://cway.cisco.com/tools/WirelessAnalyzer/ , which is always useful after an upgrade too , for problematic clients use client debugging and have these analyzed with : https://cway.cisco.com/tools/WirelessDebugAnalyzer/

 M.

[Scott Fella]

Never had any issues with PSK when upgrading to 8.10.x.  Maybe run a diff with your config on 8.9 and then when you upgrade to 8.10 and see if a bit on your WLAN has changed or a feature was added.  What you should do is test with a controller on 8.10 and create the SSID new.  First start with an open SSID and make sure that works and then try PSK.  Don't enable all the features in the WLAN. start with the basic and work up until it breaks, then you will know what config bit breaks your environment.

[Rich R]

Agreed with Scott - it's most likely one of the new features on the WLAN so compare configs side by side.
Things like PMF, FT etc can be troublesome.  We ran 8.10.162.0 for a long time without any trouble and now 8.10.181.0 also good (we're not affected by the bug mentioned above)
Did you run a debug on one of the clients with a problem?