topic Re: AP not joining WLC in Wireless

AP not joining WLC

gija — Mon, 12 Feb 2024 14:01:27 GMT

Hi,

I have some APs which are not connecting to 9800 controllers.

Reason for last AP connection failure is showing as "DTLS close alert from peer" or "DTLS handshake expired." Can anybody please explain how to resolve this issue?

Thanks in advance.

Re: AP not joining WLC

balaji.bandi — Mon, 12 Feb 2024 14:07:14 GMT

What IOS XE code running on Cat 9800 (worth upgrading 17.9.4a) most problem Fixed

what AP Model ? Hope you have Licenses.

is the AP and WLC in same VLAN - is there any Firewall between then you need to Open some ports for the AP to register with WLC.

APWAP uses the UDP Ports 5246 (for CAPWAP Control) and 5247 (for CAPWAP Data).

connect console to AP and post complete boot log until failed to register to WLC.

check the AP joining process :

https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9120axe-access-point/221056-understand-the-ap-join-process-with-the.html

also try clearing the config on AP :

# clear lwapp private-config

Re: AP not joining WLC

jagan.chowdam — Mon, 12 Feb 2024 14:43:09 GMT

You can also check the following AP join process troubleshooting guide to verify the issue

https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/218396-troubleshoot-catalyst-9800-ap-join-or-di.html

4.- In case the errors are seen in the DTLS phase we can check which type of certificate and ciphers are used for AP DTLS handshake.

show wireless certification config !! Check DTLS version and cipher suite
show wireless management trustpoint !! Type of certificate used
show wireless dtls connections !! Show if DTLS is established for capwap control/data ports used

Jagan Chowdam

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Re: AP not joining WLC

Leo Laohoo — Mon, 12 Feb 2024 22:05:03 GMT

What are the model of APs involved?

How many APs does the controller currently have?

What firmware is the controller on?

What is the uptime of the controller?

Re: AP not joining WLC

gija — Tue, 13 Feb 2024 10:48:42 GMT

The WLC is 9800-40 series and code is 17.9.4. Most of the AP models are 2802I-B-K9 and 2802E-B-K9

Re: AP not joining WLC

Leo Laohoo — Tue, 13 Feb 2024 21:57:47 GMT

How many APs are currently connected to the controller?

Re: AP not joining WLC

balaji.bandi — Wed, 14 Feb 2024 00:29:28 GMT

None of them joining to WLC or only few, can you connect the console to AP post complete boot logs

Re: AP not joining WLC

Rich R — Sun, 18 Feb 2024 10:25:20 GMT

Do you have the latest SMUs and APSP installed?
17.9.5 is released now and contains all those same fixes plus some extra ones so might also want to consider that.

Re: AP not joining WLC

gija — Tue, 20 Feb 2024 22:25:00 GMT

Yes, we have installed latest SMUs. Regarding APSP I'm not sure. I am not able see any file added in APSP tab under Software Management tab in the controller.

Re: AP not joining WLC

gija — Tue, 20 Feb 2024 22:00:29 GMT

Only few APs are not joining, like 5 to 10 APs.

Re: AP not joining WLC

gija — Tue, 20 Feb 2024 22:01:12 GMT

Around 215 APs are currently connected to WLC.

Re: AP not joining WLC

Rich R — Wed, 21 Feb 2024 01:24:55 GMT

"show install summ"
APSP8 is CSCwi44524
https://software.cisco.com/download/home/286316412/type/286325254/release/17.9.4

"sh ap image file summ" will show AP image version 17.9.4.208 for APSP8.

If you don't have the APSP installed then you're missing numerous AP fixes.
https://www.cisco.com/web/software/286325254/165945/C9800-universalk9_wlc.17.09.04.CSCwi44524.txt
https://www.cisco.com/web/software/286325254/165945/Release_Notes_9800_APSP_17_9_4.pdf

Re: AP not joining WLC

Mark Elsen — Wed, 21 Feb 2024 07:31:35 GMT

- Have a checkup of the 9800 controller(s) configuration(s) with the CLI command show tech wireless and feed the output into
Wireless Config Analyzer

- Use commands from : https://logadvisor.cisco.com/logadvisor/wireless/9800/9800APJoin
for further troubleshooting

- Checkout AP stats using : https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/217738-monitor-catalyst-9800-kpis-key-performa.html#anc4

Re: AP not joining WLC

felixngu0260 — Tue, 16 Jul 2024 05:23:47 GMT

In my case, it was due to IP address conflict / duplicate IP address of APs