Wireless Interference on Cisco 5508

[dbartwal2015]

Hi Everyone,

I have a query on the Wireless interfernce issue. 

Does connected users get disconnect if the interfernce levele is high?

As  we have observed the there users getting randomly disconnected in the network and after performing a passive survey we found the there is number of rogues Ap's in the network.

I am unable to find any documents thats statets that the interfernce will disconnect any connected users.

Kindly suggest.

Regards,
Deep Bartwal

[Sandeep Choudhary]

yes it can block the wireless network.

Better to do a complete site survey!!(Pre and post deployment)

Regards

Dont forget to rate helpful posts

[dbartwal2015]

Thank you Sandeep,

The site is around 2 years old and pre-post has been done.
Do we have any document that particular says that disconnection happens due to interfernce or can we get any debug logs for the disconnetion (that happens due to interfence).

Regards,
Deep

[Sandeep Choudhary]

I dont know about any debug interference related command...but if there is possibility of significant non-802.11 interference in the environment (more likely in 2.4GHz than in 5GHz), then get a a spectrum capture near the location of concern during the the time of concern. This could be done with Spectrum Expert with CleanAir APs, or with Chanalyzer from Metageek or any other tool.

can you paste the error logs from WLC CLI.

debug clinet <mac address>

Regards

Dont forget to rate helpful posts

[Scott Fella]

Just to add... there will always be a lot of rogue AP’s especially when users have their hotspots turned on their phones and printers that may have wireless capabilities for example. Also if there are adjacent tenants in the building that has wireless. I would review the survey results and then gather information from the users whom are complaining and having issues. Can also be an issue with the device as far as driver versions, etc.  I would look at the overall utilization from the AP/Controller perspective and then also look at the debug client like Sandeep mentioned. You need to gather more info and try to correlate what the users are experiencing especially if you can narrow it down to a specific device, driver, area of the building, application or roaming to give a few examples. 

[dbartwal2015]

Thank you Scott and Sandeep for your expert advice on this topic :)

We had tried to narrow down to a specific device, driver, area of the building, application or roaming. But the disconnection is totally random. There is no fix time or place or device.

Roaming is ruled out, as the user sitting next to the AP are also getting DC.

We havent captured any debug logs yet, the only thing we have caputred is the passive Survey, which shows interfernce due to hotspots and other non-cisco Wi-Fi Ap's.

I am trying to add the non Cisco Wi-FI Ap's to the Freinds AP list and even try to limit them in the network. (i feel it will help a bit)

Secondaly will debug the logs and share.

Regards,

Deep Bartwal

[Scott Fella]

Adding the rogue to the friendly list just doesn’t show the alerts but will not help your situation. Bottom line is, either all devices are affected or not. That is what you need to start with. If there are users that have no issues, then you have to look at the ones that complains.

[patoberli · Accepted solution]

Also, what version is running on the WLC? There were some versions in the past that could cause the AP to stop processing packets from time to time.
But I also suggest to first run some debugs. How often does it happen for an affected client?

[dbartwal2015]

Hi Patoberli,

I have Cisco Tac opened up and have got the solution.

It is a  bug in the WLC Code 8.2.151.0. for Cisco AP 3802I access point.

Below is the link from the cisco tac.

https://www.cisco.com/c/en/us/support/docs/field-notices/702/fn70208.html

Thank you every1 for the support.

Regards<
Deep

[Scott Fella]

Thanks you for posting the solution to your post. This will help others whom may run into the same issue.