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New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Hello,

I work in Australia and am currently haveing the following issue with my companies WLC and APs.

AP: AIR-LAP1042N-N-K9 (country code Australia)

WLC: 2504 (contry code Australia)

The light weight APs connect and join to the Cisco WLC and show this on the web GUI, but they randomly just dissconnect as say "not joined" then they will join again. Sometimes it will be stable for a while othere times it will happen quite frequently. I have attached some of the summarie errors from a few of the APs.

We have APs located in different parts of the world all connecting back to the same controller in our head office.

The error below is one that I see quite often, but cannot seem to find much information on the cause.

"number of message retransmission to the ap has reached maximum site"

If you need any mor einformation please do not hesitate to ask.

Any help would be greatly appreciated.

Kind Regards,

-Jake

30 REPLIES
Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

We have APs located in different parts of the world all connecting back to the same controller in our head office.

This could be your reason.  The APs heartbeat probably couldn't see the WLC, possibly due to congestion, and the WLC has marked them as "dead".

Go to the Monitor > Access Point Summary > All APs > Detail > click on the AP.

Under the Generals tab, under Time Statistics, what figures do you have there? 

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Helo Leo,

Thank you for such a quick responce. Is there any setting I can update on my WLC to stop it form marking the APs as "Dead"?

Please find attached the TIme Statisitcs for all of the APs. I have named them according to their country location.

Kind Regards,

-Jake

America APs

Australia APs

The above AP was resently reset by me.

Ireland

UK

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

You may need to consider FlexConnect.

Who's your WAN provider?  Telstra, Optus?

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Telstra is the WAN provider, hmmm we already have FlexConnect enabled. What does FlexConnect do exactly?

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Also i was looking at the Wireless LAN Complinace Status and it says the 'N' is the country code for Australia? Is this correct? I have seen a few, A, N, Z? What hapens when the Country code of the Controller and AP dont match up? Or from the image at the bottom (I am using 802.11b/g/n) the APs will need to be AIR-LAP1042N-A-K9?

AP: AIR-LAP1042N-N-K9 (All APs the same)

(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 15.0

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

Configured Country............................... AU  - Australia

Maximum number of APs supported.................. 25

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

In regards to regulatory domain, that's a separate issue.  Your APs deployed in US, for example, should be using "-A" but that will complicate what channels you can use.  But this is not what is happening.

I believe that your APs are loosing heartbeat to your WLC.  FlexConnect is good because the AP can remain operational even if it's lost the heartbeat to your controller.  The main proviso with FlexConnect is there's got to be a local authentication to authenticate new users.

Your geographical location sounds like you're from DFAT. 

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Hi Leo,

So when you say:

The main proviso with FlexConnect is there's got to be a local authentication to authenticate new users.

Do you mean local authenitcation such a RADIUS server or something to authenticat users connecting to the APs?

Sorry if I sound a little noobish Wireless isnt my strong point.

Cheers.

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Do you mean local authenitcation such a RADIUS server or something to authenticat users connecting to the APs?

Yes.  And here's the logic:

Flexconnect is good when you DON'T have any local WLC at the site.  This means that the AP will still go a WLC but to do so without overwhelming or monopolizing the WAN link.  Flexconnect was designed for this purpose.  Now, Flexconnect gets even better.  If in local mode, when a WLC or WAN link goes down, the APs go "dumb".  They just sit around and wait for the WLC to get back.   But with Flexconnect, when the WAN link or the WLC goes down the AP still operate like normal.  So the question is this:  If you have Flexconnect and the WLC and the WAN link goes down, how do you authenticate new user if you don't have any local authentication.  Remember your WAN link is down.  So this is why Flexconnect requires you have a local authentication server so when the WAN link is down, new users can get authenticated.

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Ahhh i see, we do have a have a local authentication server, but would this explain why the APs completly dissassciate from the WLC and then rejoin? Or is there something else that is requred to be configured a long with flexconnect?

Hall of Fame Super Gold

Re: Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop ou

Ahhh i see, we do have a have a local authentication server, but would this explain why the APs completly dissassciate from the WLC and then rejoin? Or is there something else that is requred to be configured a long with flexconnect?

Your common denominator here is your WAN link, Telstra.

I know it's difficult to talk to Telstra when it comes to getting them to figure out why your APs get disconnected.  Heck, having dealt with them in the past, their immediate response is "it's not our fault, it is yours".  Telstra's motto is "the customer is ALWAYS WRONG". 

Your APs loose contact to your controllers because their heartbeat gets "lost" or gets significantly delayed.

Flexconnect is a potential solution.  Another one is to put a small WLC, like a 2504, at each site.

Another solution is to investigate.

If you need to investigate, look for a pattern when this occurs.  Do the APs loose heartbeat during AU daytime/worktime or ALL the time?  Weekdays/weekends.  Blah, blah, blah ...

Before you go to Telstra, make sure you look at your network as well.  Make sure the link from your core switch and core routers to your WLC is working fine and there are no signs of congestions, line errors, etc.

Your APs do not have QoS enabled, do they?  I hope not.

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Hi Leo,

I did some reading FlexConnect, I was wondering if there are ASAs in place will this affect FlexConnect? Would ACLs need to be put in place on the WAN providers side or port forwarding?

Cheers,

-Jake

Cisco Employee

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

since you are APs are joining the controller sometimes , there shouldn't be any kind of filters that might block the capwap data and cotnrol traffic.

Primarily the issue is with AP heartbeats getting lost.

You have to make sure about couple of things:

- Round trip latency is within the flexconnect guidelines

it shouldn't be more than 300 ms.

you can use the link latency feature on the flexconnect APs to make sure that you are adhering to the aforementioned guideline

wireless --> click the flexconnect AP  --> advanced --> enable link latency

hit apply

then go to advanced tab for that particular AP to see the figures.

- Make sure to prioritize the capwap traffic between the AP and the controller to avoid any delay when congestion happens across the wan link.

check the following link for flexconnect deployment:

http://www.cisco.com/en/US/partner/docs/wireless/controller/7.2/configuration/guide/cg_flexconnect.html#wp1241304

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Hall of Fame Super Silver

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Yeah... maldehne is right on... also don't look at the controller association latency because that is misleading in a way.  Thats cumulative and if you look at the screen shot from my FlexConnect AP, it has 3m 39s.  The AP is connected to the same switch that the WLC is connected to in my home lab.  Look at the local mode AP also.

FlexConnect

Local Mode

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

-Scott
*** Please rate helpful posts ***
New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

I had a thought, would it be better to turn flex connect off on the APs that are onsite with the WLC? Its just a thought, plesae correct me if I am going off in a tangent.

Cheers

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

If the site does not have any local authentication server, then you should be in local mode.

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

I have enabled the link latency there were only two APs that were over the 300ms mark all the others were around 2-50ms Max.

Hall of Fame Super Silver

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

It's probably not that... is your AP's in local mode or FlexConnect?  Like Leo mentioned in his post, you should consider using FlexConnect mode and not local mode.  I will only use local mode when the AP's are located in the same building as the WLC or if they have like a OptiMAN or GigaMAN circuit.

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

-Scott
*** Please rate helpful posts ***
New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Hi Scott,

All the APs are in flexconnect mode, maybe flex connect is misconfigure? I was just thinking of changing the APs on site to local mode.

Hall of Fame Super Silver

Re: Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop ou

APs that are local where the wlc's are located should be left at local mode. Any other AP's at different building that goes thought your WAN should be FlexConnect. That's what I would do.

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

I have shifted the APs that are located locally to the WLC to local mode. We just lost connectivity again, is there any way to increase the amount of time the WLC will wait for a heat beat from the APs?

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

In your particular case, I don't believe enabling Link Latency will work.

It's happening now?

Do you have Telstra's GWIP service?

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Yeah it is happening now. No we do not have Telstras GWIP Service. (im not entirely sure what that is).

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

GWIP = Government-based Wideband IP.   It's Telstra's network for government.

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Oh i see, no we dont have GWIP we are not a government organisation.

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Do you have QoS enabled in your network?

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

no i dont, what traffic would i give preference to in terms of the wifi? CAPWAP? LWAPP?

Hall of Fame Super Gold

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

LWAPP = CAPWAP

Cisco Employee

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

when you do the required classification to pritize your traffic you should pay attention to the port numbers.

If you are using capwap , you should prioritize udp 5246 and 5247

if you are running old release you should prioritize UDP 12222 and 12223

New Member

Cisco AIR-LAP1042N-N-K9 connecting to Cisco 2504 WLC drop outs

Hey All,

Sorry I haven't replyed for sometime I was on leave. I managed to find the issue. What happened was a second cable was plugged into the WLC and back into the same switch, causing a loop. As soon as this was removed everything became satable.

I really appreciate all the help and advice on this issue. I learnt a lot.

Kind regards,

-Jake

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