Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

Lightweight APs intermittently shutting down after conversion from autonomous

Hi all,

we have an environment with one WLC 2504 and three AP1142N APs. The APs used to be autonomous for about 2 years, and we never had any problems with them. The reason that led us to get a WLC was that Bonjour wasn't working in the wireless segment. So we converted the APs to lightweight mode and had them join the WLC.

This worked very well and our problems with Bonjour were gone, but we now have the problem that two out of the three APs experience random reboots from time to time.

Usually they recover and are able to join the WLC again, but sometimes they are just completely gone (not pingable anymore, LED stays off) -- in that case only a power cycle will help.

The traps on the WLC look like this:

16 Thu Mar 27 15:46:56 2014 AP Disassociated. Base Radio MAC:cc:d5:39:1f:9f:70
17 Thu Mar 27 15:46:56 2014 AP's Interface:1(802.11a) Operation State Down: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Max Retransmission Status:NA
18 Thu Mar 27 15:46:56 2014 AP's Interface:0(802.11b) Operation State Down: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Max Retransmission Status:NA
 
and after the reboot:
 
9 Thu Mar 27 15:49:50 2014 AP's Interface:0(802.11b) Operation State Up: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Radio interface reset. Status:NA
10 Thu Mar 27 15:49:50 2014 AP's Interface:0(802.11b) Operation State Down: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Radio interface reset. Status:NA
11 Thu Mar 27 15:49:50 2014 AP's Interface:1(802.11a) Operation State Up: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Radio interface reset. Status:NA
12 Thu Mar 27 15:49:50 2014 AP's Interface:1(802.11a) Operation State Down: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Radio interface reset. Status:NA
13 Thu Mar 27 15:49:47 2014 AP's Interface:1(802.11a) Operation State Up: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Unknown Reset Status:NA
14 Thu Mar 27 15:49:47 2014 AP's Interface:0(802.11b) Operation State Up: Base Radio MAC:cc:d5:39:1f:9f:70 Cause=Unknown Reset Status:NA
15 Thu Mar 27 15:49:46 2014 AP 'cisco-pro-2', MAC: cc:d5:39:1f:9f:70 disassociated previously due to AP Reset. Uptime: 0 days, 00 h 01 m 17 s . Reason: power loss.
 
The stated reason in the last trap varies between "power loss" and "reboot command from AP console.".
 
Power loss seems obvious enough, but I wonder why the same AP worked fine for two years in autonomous mode. One of the two APs affected is connected to a Cisco SG 300-10P switch which shows about 11000 mW power consumption, and AFAIK the limit with 802.3af is 15400 mW, so there should be enough power here.
 
And I've never issued reboot commands on individual APs, so I have no clue why that reason would be given.
 
WLC info:

(Cisco Controller) >show sysinfo

 

Manufacturer's Name.............................. Cisco Systems Inc.

Product Name..................................... Cisco Controller

Product Version.................................. 7.4.100.0

Bootloader Version............................... 1.0.16

Field Recovery Image Version..................... 1.0.0

Firmware Version................................. PIC 16.0

 

 

Build Type....................................... DATA + WPS

 

System Name...................................... controller

System Location.................................. 

System Contact................................... 

System ObjectID.................................. 1.3.6.1.4.1.9.1.1279

IP Address....................................... 10.10.0.187

Last Reset....................................... Power on reset

System Up Time................................... 18 days 1 hrs 15 mins 47 secs

System Timezone Location......................... (GMT +1:00) Amsterdam, Berlin, Rome, Vienna

System Stats Realtime Interval................... 5

System Stats Normal Interval..................... 180

 

 

--More-- or (q)uit

Configured Country............................... CH  - Switzerland

Operating Environment............................ Commercial (0 to 40 C)

Internal Temp Alarm Limits....................... 0 to 65 C

Internal Temperature............................. +25 C

External Temperature............................. +28 C

Fan Status....................................... 4200 rpm

 

State of 802.11b Network......................... Enabled

State of 802.11a Network......................... Enabled

Number of WLANs.................................. 2

Number of Active Clients......................... 56

 

Memory Current Usage............................. Unknown

Memory Average Usage............................. Unknown

CPU Current Usage................................ Unknown

CPU Average Usage................................ Unknown

 

Burned-in MAC Address............................ EC:E1:A9:54:A0:20

Maximum number of APs supported.................. 5

 

Any pointers would be greatly appreciated.
Regards,
Dorian
4 REPLIES
Hall of Fame Super Gold

I'm leaning towards a faulty

I'm leaning towards a faulty cable.  

New Member

Leo,many thanks for your

Leo,

many thanks for your answer. I agree that the cable is the most likely culprit, I'm just wondering why two APs are affected at the same time, and why both of them have worked fine for years when they were running the autonomous firmware. Do the APs have higher power requirements when connected to a WLC (because of TX power adjustments maybe)?

Hall of Fame Super Gold

Hi Dorian,  Cables don't

Hi Dorian, 

 

Cables don't "last forever".  I have seen, time and time again, how an AP works for >2 years and one day, out of the blue, have cable issues.  

 

Unfortunately, I don't believe the model of LAN switch you are using supports TDR, however, if you have something (like a Fluke DTX 1800) or another switch which can support TDR, I'd recommend you check it out.  

New Member

If anyone in the future

If anyone in the future stumbles upon this thread, as a first step I had exchanged the two problematic APs (not the cables though), and they have been working happily ever after without any reboots. It's a kind of magic.

Leo, thanks again for your insights.

 

215
Views
0
Helpful
4
Replies
CreatePlease to create content