Problem with wireless APs Disassociating from 2106 controller

heslegrave · ‎01-26-2009

Hi..

I seem to have a problem with the stability of my wireless infrastructure. The problem seems to be that the APs Disassociate from the controller and associates again after a while. Sometimes I even have to reset the APs to re-associate.

The only help from the logs by the controller, is some lines mentioning that the AP of a certain MAC-address is disassociated with cause unknown..

Does anyone here know of a probable solution to such a problem? Or maybe just some way to debug the problem and find a solution myself.

It is probable that I myself are the cause, as this is my first set-up of a controller-based Wi-Fi, thus being a novice.

I have some guesses to what could be the cause:

- Heat problem: The APs get hot and are unable to operate. This is a guess because it cannot read sensors (I don't know if these 'sensors' are temp. sensors?)

- Rougediscovery-safty-issue: There are lots of existing private wi-fi networks reachable, and maybe the APs drop the connection upon discovery of too many rouge APs, due to some security-setting?

- Rx Multicast: The log includes many lines of error mentioning the RX Multicast Queue being full?

Does anyone have any idea what is wrong. In the beginning it worked very good, but now after about six months of operation it begins with this. I may just have made some problem with the configuration, but I can't seem to find a solution.

The controller is a Cisco 2106 Wireless lan controller and the four APs connected are AIR-LAP1131AG.

PoE is not used as our switches does not support this feature..

Any help is greatly appreciated.

/Jais

Leo Laohoo · ‎01-26-2009

1. When the AP's dis-associate/associate, what are the event logs on the switch and on the AP's themselves?

2. Do you have any other WLC anwhere in the network?

3. What is the Firmware of the WLC?

heslegrave · ‎01-27-2009

Thank you for your response..

1.: The only logging I seem to be able to find are some message logs, here is a fraction containing a disassociation and an association following:

-------

13 - Tue Jan 27 10:58:40 2009 - Rogue AP : 00:15:e9:03:b8:9a detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -74 and SNR: 16

14 - Tue Jan 27 10:58:40 2009 - Rogue AP : 00:17:9a:5b:bb:07 detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -84 and SNR: 9

15 - Tue Jan 27 10:58:40 2009 - Rogue AP : 00:1a:92:0e:db:3d detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -89 and SNR: 4

16 - Tue Jan 27 10:58:40 2009 - Rogue AP : 00:17:31:d5:a8:71 detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -93 and SNR: -4

17 - Tue Jan 27 10:52:41 2009 - AP's Interface:1(802.11a) Operation State Up: Base Radio MAC:00:1e:f7:76:23:00 Cause=Unknown

18 - Tue Jan 27 10:52:41 2009 - AP's Interface:0(802.11b) Operation State Up: Base Radio MAC:00:1e:f7:76:23:00 Cause=Unknown

19 - Tue Jan 27 10:52:39 2009 - AP Associated. Base Radio MAC: 00:1e:f7:76:23:00

20 - Tue Jan 27 10:51:27 2009 - Rogue AP : 00:13:f7:a4:13:e1 detected on Base Radio MAC : 00:1f:9e:27:46:70 Interface no:0(802.11b/g) with RSSI: -91 and SNR: 1

21 - Tue Jan 27 10:50:33 2009 - AP Disassociated. Base Radio MAC:00:1e:f7:76:23:00

22 - Tue Jan 27 10:50:33 2009 - AP's Interface:1(802.11a) Operation State Down: Base Radio MAC:00:1e:f7:76:23:00 Cause=Unknown

23 - Tue Jan 27 10:50:33 2009 - AP's Interface:0(802.11b) Operation State Down: Base Radio MAC:00:1e:f7:76:23:00 Cause=Unknown

24 - Tue Jan 27 10:49:58 2009 - RX Multicast Queue Full

25 - Tue Jan 27 10:47:32 2009 - Rogue : 00:19:cb:33:8c:9f removed from Base Radio MAC : 00:1f:9e:27:46:70 Interface no:0(802.11b/g)

26 - Tue Jan 27 10:45:27 2009 - Rogue AP : 00:0e:2e:93:be:d3 detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -94 and SNR: -3

27 - Tue Jan 27 10:44:28 2009 - Rogue : 00:1f:c6:f1:e1:bc removed from Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g)

28 - Tue Jan 27 10:42:27 2009 - Rogue AP : 00:02:cf:90:ab:e6 detected on Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g) with RSSI: -89 and SNR: 2

29 - Tue Jan 27 10:41:32 2009 - Rogue : 00:13:f7:a4:13:e1 removed from Base Radio MAC : 00:1e:f7:76:23:00 Interface no:0(802.11b/g)

-----

I hope it's readable..

2.: No, there is only one WLC on the network, and all the AP's are connected to it through RJ45-cables.

3.: The SW-version is 4.0.217.0

Furthermore it has this little line:

Internal Temp.: Sensor Failed

(I can't recall any other msg. in that line)

Do you think it might be related to a heat-problem ?

Leo Laohoo · ‎01-27-2009

Thanks for the output, unfortunately, it is does not help alot. The logs only show the AP identifying and classifying a Rogue AP.

Is the following logs FROM the AP itself? I am more interested in the DISCOVERY/JOIN messages when the AP dis-associate/associate itself from the WLC (and other subsequent log messages).

I am not ruling out the heat issue as of yet.

heslegrave · ‎01-27-2009

The log was from the webinterface of the WLC.. I don't really know how I can get any other logs from either the AP's or the WLC, but if you could tell me a way to get a better or more detailed log from the WLC or maybe just a log from the AP's..

How to do that? I can connect to the WLC with a terminal console if needed but then I need to know the command to retrieve the logs?

Thank you..

Leo Laohoo · ‎01-27-2009

You can enable remote telnet to the AP by doing the following command on the WLC:

config ap telnet enable

Telnet in using the Username/Password of Cisco/Cisco and check the logs.

heslegrave · ‎01-28-2009

Ahh.. Okay, I will try that.. thank you