How do I check to verify that APs are broadcasting SSIDs? 9800 WLC

[JWHolm81891]

I have a location that has been working well for several months to maybe over a year now that all of a sudden has an issue where clients can't authenticate or can't connect. They are getting on their phones a “couldn’t authenticate connection” error, and the iPad used for a room just says “couldn’t connect to network”. Every once in a while if they attempt to connect 5 or 6 times in a row it will randomly work and stay connected for a few hours, but there hasn’t seemed to be any kind of pattern to it. Looking in the 9800 controller, everything is good, switches are good. I'm a little lost as to what it could be all of sudden. No config changes have been made. They were configured in flex mode. How do I go about checking if the APs are receiving the config and are broadcasting the SSIDs correctly?

[Leo Laohoo]

1. What is the firmware of the 9800?
2. What authentication method, PSK or RADIUS?
3. What does the log say?

[marce1000]

 - Is the baseline wireless environment still 'green' meaning , are for instance interferers growing and or disturbing your wireless network ? Also review the 9800  configuration with the CLI command : show  tech wireless , have the output analyzed by  https://cway.cisco.com/tools/WirelessAnalyzer/  , please note do not use classical show tech-support (short version) , use the command denoted in green for Wireless Analyzer. You can also perform client debugging  : https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/213949-wireless-debugging-and-log-collection-on.html  , you can have these analyzed with : https://cway.cisco.com/tools/WirelessDebugAnalyzer/

 M.

[ammahend]

There is no wrong way to start, you can first start by looking at AP and making sure AP has all 3 tags assigned and none of the tags are default, it will mean whatever you configured on wlc is pushed to the AP, then  you can run a radioactive trace for any 1 client MAC address with issues, then if possible do a wireless capture at site and share here. Wireless connection goes through several stages before connecting, we need to understand at what stage it’s failing first.