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1131AG APs discovery stops at CFG

Hi All,

I have been to a customer site and experienced a strange problem that I have have not got to the bottom of! Details below:

5508 WLC on 7.0.116.0

AP1131AGs deployed onsite

7 of these 1131AGs (out of 50 connected to the WLC)

All APs discover the WLC and get a discovery response – A DTLS tunnel is setup between the AP & WLC – the AP then starts to initiate a config download but runs into a sequence shown below:

---------------------------------------------------------------------------
*Jan 24 11:16:00.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:00.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:00.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:00.647:         Msg Length : 1916
*Jan 24 11:16:00.647:         Msg SeqNum : 1
*Jan 24 11:16:03.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 1 Max Re-Transmission Value=5

*Jan 24 11:16:03.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:03.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:03.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:03.647:         Msg Length : 1916
*Jan 24 11:16:03.647:         Msg SeqNum : 1
*Jan 24 11:16:06.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 2 Max Re-Transmission Value=5

*Jan 24 11:16:06.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:06.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:06.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:06.647:         Msg Length : 1916
*Jan 24 11:16:06.647:         Msg SeqNum : 1
*Jan 24 11:16:09.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 3 Max Re-Transmission Value=5

*Jan 24 11:16:09.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:09.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:09.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:09.647:         Msg Length : 1916
*Jan 24 11:16:09.647:         Msg SeqNum : 1
*Jan 24 11:16:12.647: %CAPWAP-3-EVENTLOG: Retransmission Count= 4 Max Re-Transmission Value=5

*Jan 24 11:16:12.647: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:12.647: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:12.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:12.647:         Msg Length : 1916
*Jan 24 11:16:12.647:         Msg SeqNum : 1
Translating "CISCO-LWAPP-CONTROLLER"...domain server (255.255.255.255)
*Jan 24 11:16:15.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 5 Max Re-Transmission Value=5

*Jan 24 11:16:15.646: %CAPWAP-3-EVENTLOG: Max retransmission count exceeded going back to DISCOVER mode.

--------------------------------------------------------------------------------------------

I used the below debugs on the AP

#debug capwap events enable

#debug capwap errors enable

#debug capwap payload enable

At this point the AP reverts back to discovery mode as the requests have been timed out.

These APs have had issues with joining the WLC for many weeks

 

·         The switches were checked for config inconsistencies on the related switches & switchports but did not find any issues.


·         We found that an AP worked on the 6th floor but not on the ground floor on a different switch. We used this as a test AP for the other areas and found that this AP would work in areas where other APs were not working even when plugged into the same switchport!

 

·        The Retransmission Count was raised to from 5 to 8 and the Re-Transmission attempts were raised from 3 to 5 on one of the APs for testing. This had no effect and the timeouts occurred 8 times before the AP gave up and started discovery again.

I di

·         As VLAN 3 was configured incorrectly for some of these APs, 2x APs picked up a DHCP IP address that was still listed in the DHCP scope on a Microsoft server. These were removed from the scope and although the APs then showed immediately on the WLC they did not join and kept experiencing the same issues.

·         I configured a new AP (1142), which joined fine on the 6th floor. The fact that this test 1142 AP couldn’t connect when on the ground, then did connect on the 4th but not when its IP was changed to that of an AP not joining leads me to think that the APs are operating as normal and the issue lies deeper into the network.

      I am now thinking this has some sort of ARP  related issue? I rebooted the WLC after clearing the ARP table and the  APs experienced the same issues, and strangely after changing the IP of a non-joining AP, this then joined but this didnt work on all of them? I did think of MTU issues as the frame length is 1916 in the above output and the switches are set to MTU of 1500, I did ignore this though after a while as other APs are functioning on the same switch fine.

SoSorry there is a lot of info there guys! I need to put most of it in though as I have not come across this before and wonder whether anyone out there has?

Th  Any suggestions would be appreciated

     Cheers

     Rocky



·         7x APs having intermittent connectivity with LS-WLANCON-01 (see attached AP fault spreadsheet for details)

·         All APs discover LS-WLANCON-01 and get a discovery response – A DTLS tunnel is setup between the AP & WLC – the AP then starts to initiate a config download but runs into a sequence shown in the attached AP_Timeouts file.

·         At this point the AP reverts back to discovery mode as the requests have been timed out.

·         This is only affecting the mentioned APs, all other APs are operating and servicing clients as normal.
*Jan 24 11:16:00.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:00.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:00.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:00.647:         Msg Length : 1916
*Jan 24 11:16:00.647:         Msg SeqNum : 1
*Jan 24 11:16:03.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 1 Max Re-Transmission Value=5

*Jan 24 11:16:03.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:03.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:03.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:03.647:         Msg Length : 1916
*Jan 24 11:16:03.647:         Msg SeqNum : 1
*Jan 24 11:16:06.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 2 Max Re-Transmission Value=5

*Jan 24 11:16:06.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:06.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:06.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:06.647:         Msg Length : 1916
*Jan 24 11:16:06.647:         Msg SeqNum : 1
*Jan 24 11:16:09.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 3 Max Re-Transmission Value=5

*Jan 24 11:16:09.646: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:09.646: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:09.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:09.647:         Msg Length : 1916
*Jan 24 11:16:09.647:         Msg SeqNum : 1
*Jan 24 11:16:12.647: %CAPWAP-3-EVENTLOG: Retransmission Count= 4 Max Re-Transmission Value=5

*Jan 24 11:16:12.647: %CAPWAP-3-EVENTLOG: Sending packet to AC

*Jan 24 11:16:12.647: CAPWAP Control mesg Sent to 10.255.100.1, Port 5246
*Jan 24 11:16:12.647:         Msg Type   : CAPWAP_CONFIGURATION_STATUS
*Jan 24 11:16:12.647:         Msg Length : 1916
*Jan 24 11:16:12.647:         Msg SeqNum : 1
Translating "CISCO-LWAPP-CONTROLLER"...domain server (255.255.255.255)
*Jan 24 11:16:15.646: %CAPWAP-3-EVENTLOG: Retransmission Count= 5 Max Re-Transmission Value=5

*Jan 24 11:16:15.646: %CAPWAP-3-EVENTLOG: Max retransmission count exceeded going back to DISCOVER mode.

·         These APs have had issues with joining the WLC for many weeks

1916
6 REPLIES

1131AG APs discovery stops at CFG

can you capture the console port of the AP, and debug mac address < ap mac address > debug capwap events enable, debug capwap errors enable?

Steve

HTH, Steve ------------------------------------------------------------------------------------------------ Please remember to rate useful posts, and mark questions as answered
New Member

1131AG APs discovery stops at CFG

Hi Stephen,

Thanks for the quick reply - too quick for me as I accidentally hit save before finishing the post!

I have some WLC output but cant find it at the moment - I will post more when I find it!

Thanks

Rocky

Re: 1131AG APs discovery stops at CFG

do a show interface vlan 3 and take a look at the counters. There could be a broadcast storm stopping the packets. The other thing to check is show spannig-tree VLAN 3 and see if it has recculated recently. You mAu want to pull this multiple times to see if it is calculating reparatively. That would also cause issues with the AP being able to join.

Steve

Sent from Cisco Technical Support iPhone App

HTH, Steve ------------------------------------------------------------------------------------------------ Please remember to rate useful posts, and mark questions as answered
New Member

Re: 1131AG APs discovery stops at CFG

Hi Stephen,

Funny you should say that about SPT, as the site have had SPT issues recently!

They configured redndant links from the edge switches to the core, but when these were tested SPT brought everything down. The redundant links were physicaly unplugged since to stop the problem.

I am not onsite to check interfaces but can ask for the engineer onsite to look at this for us.

I have attached the debug capwap events & errors from one of the APs

Thanks again

Rocky

Hall of Fame Super Gold

1131AG APs discovery stops at CFG

Try to convert one of the problematic 1130 to autonomous and then back to CAPWAP.  See if it works. 

New Member

1131AG APs discovery stops at CFG

Hi Leo,

I did reset an AP with the mode button but it then corrupted its image and i didnt have a power block handy to do as you suggest.

I did sort of rule this out though because I had a brand new 1142 ruuning a different ios to the 1130s that i got joined to the wlc in one place then had the exact same issue when plugged in elsewhere.

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