Client cannot associate to 5G SSID !!!

[Rps-Cheers]

Hi wireless expert:


These days,i have a problem that is all clients cannot associate to 5G wifi,only 2.4G OK.There are wlc and AP module as below:


WLC: 2504   ; software version:8.2.121.5

AP: AP1852


i have run "debug client xx.xx.xx.xx.xx.xx" command to try get the associate info.but unfortunately,there is no any info display.

other info：5G channel don't have interference,and channel  utilization is so low.


So i don't know what reason about this problem,i guess the ap drop all traffic of 5G ,Can you tell me the probably reason？

[Sandeep Choudhary]

is 5Ghz Radio is enabled ?

is SSID visible ?

how did you configre dthe ssid ...with WPA2/aes or wpa/tkip ?

Regards

Dont forget to rate helpful posts

[Rps-Cheers]

of course，and we can see the ssid about the 802.11a-only，just cannot associate it.
You also give me a idea，maybe it's a problem about wpa2，but it operate well before.But i will change it to test.

thanks

[Sandeep Choudhary]

disable 802.11b/g/n (2.4 Ghz) on the wlan and try to connect a clinet to ssid with 5Ghz only...and see the logs in WLC.

If possible paste here as well to analyze the root cause.....

Regards

[Rps-Cheers]

i have disabled 2.4g，just only have 5g.And client cannot associate to 5g ssid.the logging don’t have useful info，and debug client mac-address have no output....

so，i guess ap drop all traffic of 5g

[Leo Laohoo]

1. Does the client actually support 5.0 Ghz?
2. Can you try with OPEN authentication?

[Rps-Cheers]

Hi Leo the client support 5g，and all devices cannot connect the 5g ssid.i have try policy to open，wpa psk，wpa2 psk，wpa+wpa2 psk. Those all failed.we can see the error:cannot connect to ‘SSID-name’. I am not sure whether there is a abnormal about wlc2504+ap1852.... That’s a so hard issue

[Leo Laohoo]

Could be CSCus83638.

Is there a reason why the controller/AP is running an old Engineering release image? Is it possible to upgrade the firmware of the controller?

[Rps-Cheers]

yes，this release is design for end user，these days，it happened all kinds of problem.for example，ap1852 disconnect，and rejoin to wlc2504，and it always happened .sometimes，it cannot join wlc2504……

it probably hit this bug，i will test the workaround

thanks

[Leo Laohoo]

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@Rps-Cheers wrote:
i will test the workaround

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See if it's possible to upgrade the firmware of the controller to, say, the latest 8.5.

[Rps-Cheers]

ok ，i will try to do it

[pwwiddicombe]

Same thing.  8.2.164.0 and 3700's - just wasn't making any sense.  Restarted 2 of the AP's and now they respond and will associate; although I gather this may be a temporary fix.  Problem is - how do you even FIND which AP's are in this state ?  I just hit the ones that really should have had connections and hadn't, but this is pretty tedious.