INTERMITTENT DISCONNECTION OF CLIENTS

[ugwuugochukwuk]

Hello All,

Good day.

I have a customer who complained that users connected to the wireless network get disconnected intermittently and this affects users productivity.

I've gone through the controller and I didn't find the possible cause.

The controller model is 3504, Also most AP's in the environment are 3800 and 2800 series.

I've attached the syslog from the controller.

Kindly assist!!!

[balaji.bandi]

try wireless debug analyzer:

https://developer.cisco.com/docs/wireless-troubleshooting-tools/#!wireless-troubleshooting-tools/9800-telemetry-pipeline---github

[Leo Laohoo]

Wow.  That text file did not contain anything useful at all.  

Kindly provide useful information, such as: 

1.  What firmware is the controller running on? 

2.  What exact model of the APs? 

3.  Are the APs in FLEX or local mode? 

4.  What EXACTLY is the problem?  

5.  Has anyone taken the time to verify the issue or is all of this completely "hearsay"? 

6.  Is the issue affecting ONE person or multiple wireless clients? 

7.  MAC address:  No MAC address or it did not happen

8.  Did anyone try to run a debug of the MAC address? 

9.  2800/3800, right?  Is the issue happening to wireless clients on 2.4 Ghz or 5.0 Ghz radio? 

10.  Is WMM turned on or off?

[ugwuugochukwuk]

Hello Leo,

Kindly find my responses to your questions in blue below:

1.  What firmware is the controller running on? 

Controller Software Version is 8.5.140.0

2.  What exact model of the APs? 

The Ap's are mostly AIR-3802P-E-K9 and AIR-2802E-E-K9

3.  Are the APs in FLEX or local mode? 

The AP's are in flex connect mode

4.  What EXACTLY is the problem?  

Clients connected to the AP's get disconnected intermittently 

5.  Has anyone taken the time to verify the issue or is all of this completely "hearsay"? 

This has been confirmed, some users experience this issue

6.  Is the issue affecting ONE person or multiple wireless clients? 

It affects multiple wireless clients

7.  MAC address:  No MAC address or it did not happen

I didn't not take note of the client's MAC address. I will do that now

8.  Did anyone try to run a debug of the MAC address? 

No I haven't do this

9.  2800/3800, right?  Is the issue happening to wireless clients on 2.4 Ghz or 5.0 Ghz radio? 

The affected AP's are 2800 / 3800. I haven't confirmed if they're 2.4GHz or 5.0 GHz clients

10.  Is WMM turned on or off?

Yes WMM policy is allowed

[Leo Laohoo]

---

@ugwuugochukwuk wrote:

5.  Has anyone taken the time to verify the issue or is all of this completely "hearsay"? 

This has been confirmed, some users experience this issue

---

WHO verified this?  If YOU did not verify this, then this has not yet been verified at all. 

---

@ugwuugochukwuk wrote:

2.  What exact model of the APs? 

The Ap's are mostly AIR-3802P-E-K9 and AIR-2802E-E-K9

---

What kind of environment is this?  What antenna is used on the 2800E and 3800P?

---

@ugwuugochukwuk wrote:

9.  2800/3800, right?  Is the issue happening to wireless clients on 2.4 Ghz or 5.0 Ghz radio? 

The affected AP's are 2800 / 3800. I haven't confirmed if they're 2.4GHz or 5.0 GHz clients

---

If this was "verified" (Question #5), this would have been evident.  So I am going to say, with Q5, NO ONE independently verified the complaint.

[ugwuugochukwuk]

Hello Leo,

Thanks for your response.

I think the issue was that the AP's were giving out Ip addresses from the native VLAN which is VLAN 1. So if the IP address pool gets filled up, the AP does not give out any IP again and when this happens, clients will not have internet access. Hence the complain..

Any ideas on how I will instruct the AP's to give out IP's from a particular VLAN other than VLAN1 ?????

[Rich R]

So now you have completely changed the description of the problem:

- You're using VLAN1 (not generally recommended) with an IP subnet which does not have enough IP addresses for the number of clients.

- You want to know how to redesign the network to use other VLANs.  There are many different possible solutions depending on your specific network requirements.

It sounds like you really need to go back to basics on how to design your wireless network and WLANs and if you cannot work out how to do that from the documentation and numerous guides then I'd highly recommend employing a qualified designer to do it for you.

Otherwise your simplest option is to use a larger IP subnet on VLAN 1 with enough IP addresses for your clients.  If you're currently using /24 then consider /23 or /22.

[MHM Cisco World]

If I am right the OLD device 802.11b are disconnect ? if yes then you need to enable it in WLC.

check this and see if these device disconnect anymore.

[MHM Cisco World]

*apfMsConnTask_5: Mar 25 17:51:57.056: %APF-3-CHECK_SUPP_RATES_FAILED: apf_utils.c:411 Could not check supported rates. Missing Supported Rate. Length :0. Mobile MAC: d6:a3:e9:3f:34:85.

this make me thing that 802.11b is not enable or some DataRate is not enable by WLC.

[Haydn Andrews]

try a driver/firmware upgrade on the client wireless drivers