Random, Intermittent Wireless Connectivity Issues

Srinivasan Nagarajan · ‎03-10-2017

Hi All,

I've got a ticket for couple of users who complained that their wireless connection drops randomly a multiple times a day and intermittently. Light Weight Access points has been configured and controlled WLC 8500 series.

Can someone please suggest Troubleshooting tips for intermittent connectivity issues.

Thanks,

Sri

Leo Laohoo · ‎03-10-2017

1. What is the exact firmware version running on the controller?

2. What is/are the different AP models deployed?

3. To those who's complained, what is the exact model of their wireless NIC and the exact version of the drivers they are running with?

4. To those who's complained, are they experiencing drop-outs when they are connected to the 802.11a or 802.11b radio?

Let's start with these basic question and see where it leads to.

Srinivasan Nagarajan · ‎03-10-2017

Hi Leo,

Thanks for replying. We're using 8500 WLC and all LAP is AIR-CAP3602I-E-K9. Clients are MAC/Android users.

Users belong to all the 4 SSID's .Please find the below and kindly suggest.

1.Software Version- 8.0.133.0 (8500 WLC)

2. AIR-CAP3602I-E-K9

3. They're mobile users. Not sure how to check for PC users.

4. We've 4 SSID and all SSID is configured with Radio Policy as "ALL".

Thanks,

Sri

Leo Laohoo · ‎03-10-2017

We're using 8500 WLC and all LAP is AIR-CAP3602I-E-K9.

Is CleanAir enabled? If not, why not?

Software Version- 8.0.133.0 (8500 WLC)

Upgrade to either 8.0.140.0 or 8.2.141.0 or (soon to be released) 8.0.150.0.

Not sure how to check for PC users.

When one of the users (who complains) are able to log in, use the CLI to get the information from the command "sh client detail <MAC address>" and paste the output into a notepad and attach to this thread for analysis.

Next, find the nearest AP where the user is and then run the following series of commands:

sh ap auto-rf 802.11a <AP name>

sh ap auto-rf 802.11b <AP name>

Srinivasan Nagarajan · ‎03-10-2017

Hi,

Clean Air has been enabled.Please find the attached logs for your reference.

Kindly suggest.

Thanks,

Sri

Leo Laohoo · ‎03-10-2017

From the output, I can confirm the following:

1. The wireless client is an Apple client (can't go any further).

2. There are better wireless signal nearby but the wireless client refuses to go join other wireless AP with better signal (-63 dBm vs -46, -47- and -57 dBm from nearby APs). I am suspecting this client is loaded with an old OS.

3. The 802.11a is clean, however, I can see that the APs are all crowding around the lower channels and I don't see any APs operating in the higher channels. The AP the client is associated on is currently operating in mid-level power. Very strange.

4. Wireless client operating in 20 Mhz channel bond.

5. Low data rates are disabled.

6. No signs of co-channel interference detected.

Post the complete output to the command "sh wlan 20".

Srinivasan Nagarajan · ‎03-11-2017

Hi Leo,

Thanks for your reply. Please suggest is there any difference b/w clients like MAC vs Windows VS Android.

Can you please summarize the basic T-shooting steps that needs to be followed when issue occurs.

Thanks,

Sri

Scott Fella · ‎03-11-2017

Just to add to my friends Leo's comments....

I think everyone here has a different way to approach troubleshooting based on their experience. When I was at CDW implementing services, you learn from your experiences and from your peers. Now that I'm not deploying in various different verticals my methodology has changed due to what I see in the environment.

Some things have not changed however, that is collenting data. You need to really identify the issue, see if you can reproduce the issue, try to isolate the issue if it's a specific client, can you isolate it by NIC and driver, isolate if it's a wireless vs wired/routing issue, 2.4ghz vs 5ghz. Once you can really identify and it's isolated to wireless, then it's easier to decide next steps. Typically it's a configuration issue, bug on the code, or client device issue.

-Scott

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-Scott
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Leo Laohoo · ‎03-11-2017

Please suggest is there any difference b/w clients like MAC vs Windows VS Android.

There are significant differences between how different wireless manufactures write their codes. This gets compounded with different OS versions operating around.

This is why I'm asking for some initial data and then will be comparing the other data with some more information I'm going to be asking later.