AP not join to WLC - Max retransmission count exceeded

[schulcz]

Hi Guys,

I have an AP in a production network that can't connect to any WLC after deployment. Image download from controller was successfull, but it got "Max retransmission count exceeded, going back to DISCOVER mode." error message during CAPWAP Configuration state, and it repeats indefinitely.

[*05/19/2023 10:55:52.4156] CAPWAP State: Join
[*05/19/2023 10:55:52.4395] Sending Join request to 172.24.6.53 through port 5248
[*05/19/2023 10:55:52.4448] Join Response from 172.24.6.53
[*05/19/2023 10:55:52.4448] AC accepted join request with result code: 0
[*05/19/2023 10:55:52.4463] Received wlcType 0, timer 30
[*05/19/2023 10:55:52.6182]
[*05/19/2023 10:55:52.6182] CAPWAP State: Image Data
[*05/19/2023 10:55:52.6186] AP image version 8.10.171.0 backup 8.10.162.0, Controller 8.10.171.0
[*05/19/2023 10:55:52.6187] Version is the same, do not need update.
[*05/19/2023 10:55:52.6473] upgrade.sh: Script called with args:[NO_UPGRADE]
[*05/19/2023 10:55:52.7045] do NO_UPGRADE, part1 is active part
[*05/19/2023 10:55:52.7113]
[*05/19/2023 10:55:52.7113] CAPWAP State: Configure
[*05/19/2023 10:55:56.3716] Re-Tx Count=1, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:55:56.3716]
[*05/19/2023 10:55:59.2189] Re-Tx Count=2, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:55:59.2189]
[*05/19/2023 10:56:01.2804] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Configure(8).
[*05/19/2023 10:56:02.0698] Re-Tx Count=3, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:02.0698]
[*05/19/2023 10:56:04.9207] Re-Tx Count=4, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:04.9207]
[*05/19/2023 10:56:07.7717] Re-Tx Count=5, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:07.7717]
[*05/19/2023 10:56:10.3088] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Configure(8).
[*05/19/2023 10:56:10.6225] Max retransmission count exceeded, going back to DISCOVER mode.
[*05/19/2023 10:56:10.6225] Dropping msg CAPWAP_CONFIGURATION_STATUS, type = 4, len = 2825, eleLen = 2833, sendSeqNum = 1
[*05/19/2023 10:56:10.6225] GOING BACK TO DISCOVER MODE
[*05/19/2023 10:56:10.6427]
[*05/19/2023 10:56:10.6427] CAPWAP State: DTLS Teardown
[*05/19/2023 10:56:11.7143] upgrade.sh: Script called with args:[ABORT]
[*05/19/2023 10:56:11.7727] do ABORT, part1 is active part
[*05/19/2023 10:56:11.7872] upgrade.sh: Cleanup tmp files ...
[*05/19/2023 10:56:11.8210] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/19/2023 10:56:11.8210] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/19/2023 10:56:26.3527]
[*05/19/2023 10:56:26.3527] CAPWAP State: Discovery
[*05/19/2023 10:56:26.3567] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*05/19/2023 10:56:26.3575] Discovery Response from 172.24.6.53
[*05/19/2023 10:56:36.0003]
[*05/19/2023 10:56:36.0003] CAPWAP State: DTLS Setup
[*05/19/2023 10:56:36.4048]
[*05/19/2023 10:56:36.4049] CAPWAP State: Join
[*05/19/2023 10:56:36.4121] Sending Join request to 172.24.6.53 through port 5248
[*05/19/2023 10:56:36.4159] Join Response from 172.24.6.53
[*05/19/2023 10:56:36.4159] AC accepted join request with result code: 0
[*05/19/2023 10:56:36.4174] Received wlcType 0, timer 30
[*05/19/2023 10:56:36.5895]
[*05/19/2023 10:56:36.5895] CAPWAP State: Image Data
[*05/19/2023 10:56:36.5898] AP image version 8.10.171.0 backup 8.10.162.0, Controller 8.10.171.0
[*05/19/2023 10:56:36.5899] Version is the same, do not need update.
[*05/19/2023 10:56:36.6186] upgrade.sh: Script called with args:[NO_UPGRADE]
[*05/19/2023 10:56:36.6797] do NO_UPGRADE, part1 is active part
[*05/19/2023 10:56:36.6864]
[*05/19/2023 10:56:36.6864] CAPWAP State: Configure
[*05/19/2023 10:56:40.3677] Re-Tx Count=1, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:40.3677]
[*05/19/2023 10:56:40.4768] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Configure(8).
[*05/19/2023 10:56:43.2185] Re-Tx Count=2, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:43.2185]
[*05/19/2023 10:56:46.0694] Re-Tx Count=3, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:46.0694]
[*05/19/2023 10:56:48.9203] Re-Tx Count=4, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:48.9203]
[*05/19/2023 10:56:50.1404] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Configure(8).
[*05/19/2023 10:56:51.7712] Re-Tx Count=5, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/19/2023 10:56:51.7712]
[*05/19/2023 10:56:54.6221] Max retransmission count exceeded, going back to DISCOVER mode.
[*05/19/2023 10:56:54.6221] Dropping msg CAPWAP_CONFIGURATION_STATUS, type = 4, len = 2825, eleLen = 2833, sendSeqNum = 1
[*05/19/2023 10:56:54.6222] GOING BACK TO DISCOVER MODE
[*05/19/2023 10:56:54.6423]
[*05/19/2023 10:56:54.6423] CAPWAP State: DTLS Teardown
[*05/19/2023 10:56:55.7143] upgrade.sh: Script called with args:[ABORT]
[*05/19/2023 10:56:55.7719] do ABORT, part1 is active part
[*05/19/2023 10:56:55.7862] upgrade.sh: Cleanup tmp files ...
[*05/19/2023 10:56:55.8200] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/19/2023 10:56:55.8201] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/19/2023 10:57:10.3491]
[*05/19/2023 10:57:10.3491] CAPWAP State: Discovery
[*05/19/2023 10:57:10.3720] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*05/19/2023 10:57:10.3722] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Discovery(2).
[*05/19/2023 10:57:10.3728] Discovery Response from 172.24.6.53
[*05/19/2023 10:57:20.0003]
[*05/19/2023 10:57:20.0003] CAPWAP State: DTLS Setup
[*05/19/2023 10:57:20.4158]
[*05/19/2023 10:57:20.4158] CAPWAP State: Join

I tried that I grab a lab switch, connect a lab wlc and this AP to the switch, but I experienced the same error.

AP regulatory domain and WLC configured country code matching, and this AP has a same regulatory domain (E) as any other of thousands that works normally with our WLCs.

I tried to ping the AP from WLC, it never drops any packet. (tried with repeat 100 and packet size 1500)

AP factory reset also did not help.

What can I do with this AP? (AIR-AP3802I-E-K9)

Thanks!

[Flavio Miranda]

Hi

 Does the join attempt populates the AP join statistics in the WLC? any message over there?

[schulcz]

Yes, I tried it in 2 separate WLCs and same error message appeared: Regulatory domain check has failed for the AP

WLC1:

WLC2 (running 8.10.185.0 software):

(Cisco Controller) >show ap join stats summary 4c:71:0d:12:34:56

Is the AP currently connected to controller................ No
Time at which the AP joined this controller last time...... Not applicable
Type of error that occurred last........................... Lwapp configuration request rejected
Reason for error that occurred last........................ Regulatory domain check has failed for the AP
Time at which the last join error occurred................. May 22 16:25:31.703

However WLCs configured country code (HU) is included in the AP regulatory domain (E) as any other APs in out network, but other APs works fine.

[Rich R]

See this field notice:
https://www.cisco.com/c/en/us/support/docs/field-notices/704/fn70479.html

[Rich R]

If it's just 1 AP then it could be a faulty AP but I would upgrade to latest TAC recommended code as per link below (currently 8.10.185.0) before jumping to any conclusion.  There have been a lot of bug fixes since 8.10.171.0.

If you still have the problem after upgrade (and another factory default reset of the AP) then RMA (assuming you have tested it in the same switch port as a working AP of the same model).

[schulcz]

The problem seems to occur only with this one AP, I tried it with fresh software (see my previous post), but got same error message. I also tried to full reset AP after software upgrade, didn't helped.

[*05/22/2023 14:28:12.5348] CAPWAP State: Discovery
[*05/22/2023 14:28:12.5355] IP DNS query for CISCO-CAPWAP-CONTROLLER.net.lab
[*05/22/2023 14:28:12.5457] Discovery Request sent to 255.255.255.255, discovery type UNKNOWN(0)
[*05/22/2023 14:28:12.5462] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Discovery(2).
[*05/22/2023 14:28:12.5465] Discovery Response from 192.168.42.222
[*05/22/2023 14:28:21.0003]
[*05/22/2023 14:28:21.0003] CAPWAP State: DTLS Setup
[*05/22/2023 14:28:21.4239]
[*05/22/2023 14:28:21.4239] CAPWAP State: Join
[*05/22/2023 14:28:21.4305] Sending Join request to 192.168.42.222 through port 5272
[*05/22/2023 14:28:21.4342] Join Response from 192.168.42.222
[*05/22/2023 14:28:21.4342] AC accepted join request with result code: 0
[*05/22/2023 14:28:21.4343] Master-Slave: role 3, master 192.168.42.124, old 0
[*05/22/2023 14:28:21.4343] Master-Slave: Set to Slave, retry 44, set_tftp_server 0, Master AP 192.168.42.124, Join role Slave, tftp_timeoutCnt 3
[*05/22/2023 14:28:21.4345] Image pre-download request for version 8.10.185.0.
[*05/22/2023 14:28:21.4346] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Join(5).
[*05/22/2023 14:28:21.4709] upgrade.sh: Script called with args:[NO_UPGRADE]
[*05/22/2023 14:28:21.5329] do NO_UPGRADE, part2 is active part
[*05/22/2023 14:28:21.5394] Resetting slave AP upgrade mode to local mode
[*05/22/2023 14:28:21.5394] Received wlcType 1, timer 120
[*05/22/2023 14:28:21.6831]
[*05/22/2023 14:28:21.6832] CAPWAP State: Image Data
[*05/22/2023 14:28:21.6835] AP image version 8.10.185.0 backup 0.0.0.0, Controller 8.10.185.0
[*05/22/2023 14:28:21.6836] Version is the same, do not need update.
[*05/22/2023 14:28:21.7234] upgrade.sh: Script called with args:[NO_UPGRADE]
[*05/22/2023 14:28:21.7833] do NO_UPGRADE, part2 is active part
[*05/22/2023 14:28:21.7902]
[*05/22/2023 14:28:21.7902] CAPWAP State: Configure
[*05/22/2023 14:28:25.5577] Re-Tx Count=1, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/22/2023 14:28:25.5577]
[*05/22/2023 14:28:28.4085] Re-Tx Count=2, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/22/2023 14:28:28.4085]
[*05/22/2023 14:28:31.2594] Re-Tx Count=3, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/22/2023 14:28:31.2594]
[*05/22/2023 14:28:34.1103] Re-Tx Count=4, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/22/2023 14:28:34.1103]
[*05/22/2023 14:28:36.9612] Re-Tx Count=5, Max Re-Tx Value=5, SendSeqNum=1, NumofPendingMsgs=1
[*05/22/2023 14:28:36.9612]
[*05/22/2023 14:28:37.3973] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: Configure(8).
[*05/22/2023 14:28:39.8120] Max retransmission count exceeded, going back to DISCOVER mode.
[*05/22/2023 14:28:39.8121] Dropping msg CAPWAP_CONFIGURATION_STATUS, type = 4, len = 2830, eleLen = 2838, sendSeqNum = 1
[*05/22/2023 14:28:39.8121] GOING BACK TO DISCOVER MODE
[*05/22/2023 14:28:39.8323]
[*05/22/2023 14:28:39.8323] CAPWAP State: DTLS Teardown
[*05/22/2023 14:28:40.9151] upgrade.sh: Script called with args:[ABORT]
[*05/22/2023 14:28:40.9729] do ABORT, part2 is active part
[*05/22/2023 14:28:40.9966] upgrade.sh: Cleanup tmp files ...
[*05/22/2023 14:28:41.0320] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/22/2023 14:28:41.0320] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).
[*05/22/2023 14:28:43.2067] Discarding msg CAPWAP_WTP_EVENT_REQUEST(type 9) in CAPWAP state: DTLS Teardown(4).

WLCs configured country code (HU) is included in the AP regulatory domain (E) as any other APs in out network, but other APs works fine.

Any other AP works fine on the same switchport.

[Rich R · Accepted solution]

Check the AP serial number against https://www.cisco.com/c/en/us/support/docs/field-notices/704/fn70479.html

You probably need to RMA the AP.

[schulcz]

Yes, You have rigth, this is the case. Thank You!