AP no longer join C9800 wlc

[Leftz]

Hi, We have C9800 WLC with version 17.5- and AP38002. both devices can ping each other. The AP could join the WLC before. But recently the APs no longer join the WLC again. Maybe some configuration has been changed on the wlc, but not sure. The below is WLC logging message and message from the AP. I notice two device time is different. but i do not think it would be a issue. Anyone has some suggestions for this? Thank you!

WLC#show logging

[*12/03/2020 00:05:20.3238] CAPWAP State: Discovery
[*12/03/2020 00:05:20.3293] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:05:20.3318] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:05:20.3517] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:05:49.7801]
[*12/03/2020 00:05:49.7801] CAPWAP State: Discovery
[*12/03/2020 00:05:49.7884] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:05:49.7907] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:05:49.7927] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:06:19.2397]
[*12/03/2020 00:06:19.2397] CAPWAP State: Discovery
[*12/03/2020 00:06:19.2455] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:06:19.2498] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:06:19.2521] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:06:36.2102] systemd[1]: sshd.service start-pre operation timed out. Terminating.
[*12/03/2020 00:06:36.2115] systemd[1]: Failed to start OpenSSH server daemon.
[*12/03/2020 00:06:36.2117] systemd[1]: sshd.service failed.
[*12/03/2020 00:06:48.6988]
[*12/03/2020 00:06:48.6988] CAPWAP State: Discovery
[*12/03/2020 00:06:48.7022] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:06:48.7180] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:06:48.7231] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:07:18.1578]
[*12/03/2020 00:07:18.1578] CAPWAP State: Discovery
[*12/03/2020 00:07:18.1615] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:07:18.1644] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:07:18.1674] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:07:47.6178]
[*12/03/2020 00:07:47.6178] CAPWAP State: Discovery
[*12/03/2020 00:07:47.6227] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:07:47.6258] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:07:47.6287] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:08:17.0779]
[*12/03/2020 00:08:17.0779] CAPWAP State: Discovery
[*12/03/2020 00:08:17.0967] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:08:17.0993] Discovery Request sent to 10.0.1.2, discovery type STATIC_CONFIG(1)
[*12/03/2020 00:08:17.1018] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*12/03/2020 00:08:46.5362]

AP:

*Jun 16 11:29:00.955: %SYS-6-LOGOUT: User zadmin has exited tty session 2(10.1.1.5)
*Jun 16 11:53:03.685: %WEBSERVER-5-SESS_TIMEOUT: Chassis 1 Session timeout from host 10.1.1.5 by user 'admin' using crypto cipher 'ECDHE-RSA-AES128-GCM-SHA256'
*Jun 16 13:24:08.182: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 192.168.1.5] [localport: 21111] at 13:24:08 Eastern Wed Jun 16 2021
*Jun 16 13:24:08.182: %WEBSERVER-5-LOGIN_PASSED: Chassis 1 Login Successful from host 10.2.1.5 by user 'admin' using crypto cipher 'ECDHE-RSA-AES128-GCM-SHA256'
*Jun 16 13:30:28.624: %SYS-5-CONFIG_P: Configured programmatically by process SEP_webui_wsma_http from console as admin on vty0
*Jun 16 13:30:29.558: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan23, changed state to up
*Jun 16 13:31:00.513: %SYS-5-CONFIG_P: Configured programmatically by process SEP_webui_wsma_http from console as admin on vty0
*Jun 16 13:40:02.076: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: zadmin] [Source: 10.2.1.5] [localport: 22] at 13:40:02 Eastern Wed Jun 16 2021
*Jun 16 13:58:29.059: %SYS-6-TTY_EXPIRE_TIMER: (exec timer expired, tty 2 (10.2.1.5)), user zadmin
*Jun 16 13:58:29.059: %SYS-6-LOGOUT: User zadmin has exited tty session 2(10.2.1.5)
*Jun 16 13:58:29.059: %SYS-5-CONFIG_I: Configured from console by zadmin on vty0 (10.2.1.5)
*Jun 16 13:59:27.324: %WEBSERVER-5-SESS_TIMEOUT: Chassis 1 Session timeout from host 10.2.1.5 by user 'admin' using crypto cipher 'ECDHE-RSA-AES128-GCM-SHA256'
*Jun 16 15:39:45.813: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 192.168.1.5] [localport: 21111] at 15:39:45 Eastern Wed Jun 16 2021
*Jun 16 15:39:45.814: %WEBSERVER-5-LOGIN_PASSED: Chassis 1 Login Successful from host 10.2.1.5 by user 'admin' using crypto cipher 'ECDHE-RSA-AES128-GCM-SHA256'
*Jun 16 15:40:11.508: %SYS-5-CONFIG_P: Configured programmatically by process SEP_webui_wsma_http from console as admin on vty0
*Jun 16 15:41:19.031: %SYS-5-CONFIG_P: Configured programmatically by process SEP_webui_wsma_http from console as admin on vty0
*Jun 16 15:41:19.978: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan23, changed state to up
*Jun 16 15:42:11.169: %SYS-5-CONFIG_P: Configured programmatically by process SEP_webui_wsma_http from console as admin on vty0
*Jun 16 16:32:05.007: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: zadmin] [Source: 10.2.1.5] [localport: 22] at 16:32:05 Eastern Wed Jun 16 2021
*Jun 16 16:33:20.936: %WEBSERVER-5-SESS_LOGOUT: Chassis 1 Successfully logged out from host 10.2.1.5 by user 'admin' using crypto cipher 'ECDHE-RSA-AES128-GCM-SHA256

[Scott Fella]

Time is important for any join process to be successful. Fix that and see if the ap joins.

[Rich R]

On boot up COS APs set the AP time to what it was the last time they booted and synced (sometime in the past)

The AP time only gets  synced to WLC time after it gets a discovery response from the WLC.

Example:

Starting Cisco system time setup...
Starting Cisco seed generation...

[*11/20/2020 23:59:59.0240] Last reload time: Jun 3 16:29:41 2021

[*06/03/2021 16:29:41.0000] Setting system time Thu Jun 3 16:29:41 UTC 2021

[*06/03/2021 16:31:16.3370] Discovery Response from 1.2.3.4

[*06/17/2021 09:07:03.0000]

[*06/17/2021 09:07:03.0000] CAPWAP State: DTLS Setup

The problem here is no response to the discovery - possibilities:

- discovery not reaching WLC

- discovery reply not reaching AP

- WLC rejecting or ignoring discovery

Requires troubleshooting with packet captures and debugs on WLC to narrow it down.

Have you tried factory default reset of the AP?

[David Ritter · Accepted solution]

what is you wireless management interface?

!

wireless management interface Vlan314
public-ip 172.25.14.10

!

[Leftz]

management interface was incorrect. Thank you

[David Ritter]

good to hear.  I readdressed my stack and lost all my AP's that way..  forgot the wmi tab..

[Tadzio]

I have a similar problem.  I have 3 3802 WAPs that won't connect to my 9800-40 WLC after a power loss, though 6 others connect just fine.  The AP's console suggests that it can't find the WLC.  I have configured the WLC as you suggested, but that hasn't made a difference.  The APs are on the same VLAN as the WLC too.  I'm baffled.

[Rich R]

1. What version of software are you running?
2. Have you done a factory default reset of those APs?