iPhones unstable on wifi

[Rene Mueller]

Hi Folks,

I am running EWC on 9115AXI Access Points. I randomly see that Apple iPhones are losing their Internet connection while they are sill on the wifi network. As a workaround I have to turn the wifi on the iPhone off an on again. This happens also when iPhones stayed really next to an AP. I don't see this kind of issue with Android devices.

I had this experience already with 1832i Mobility Express and also with 2802i Mobility Express.

In every setup (1830, 2802, 9115) I setup best practices on the ME or EWC controller with no success.

Anyone an idea what might be the issue?

[Kasun Bandara]

hi @Rene Mueller 

1. do you have any NAC or other controlling in network based on device profiles?

2. what is the WLC OS version?

3. have you done any debug related to the relevant device when issue occurred? 

[Scott Fella]

@Rene Mueller adding to what @Kasun Bandara requested, does this issue happen on various encryption types open vs PSK vs 802.1x? Has this worked before and was it the latest update when you noticed this issue?  I'm assuming this is not a new wireless setup.

[Saikat Nandy]

Depending on the nature (roaming or stationary user) and frequency of the issue, the best approach to narrow down the issue would be - 

1. Connect the iphone to the AP. Download a terminal application and initiate ping to GW/Google.

2. Collect RA trace on EWC or debug client on ME. Make sure you capture the problem time.

3. SSH to the AP, where the iphone is connected and run client trace

These data will give clarity what is happening.

[Leo Laohoo]

Start first by rebooting the AP.  

[Rich R]

The question has already been asked and this info should always be included when asking question - what version of software are you using?

If not already then look to update as per the TAC recommended link below.

[Rene Mueller]

Thank you very much for all your replies. 

Here are my answers:

• we use PSK for authentication, did not test others and cannot test open as this is insecure
• it only happens to apple devices, in our case iPhone. Other devices like Android or wifi TV stations are keeping their connection
• we tested with the latest iOS on Apple and also with the latest and recommanded versions of Mobility expresss as well as EWC.
• All APs have been rebooted serveral times. 
• since we started with 1832, 2802 and now 9115 APs the problem always stayed on the platform. so there was no working scenario
• we don't separate 2.4Ghz and 5Ghz. 
• it happens when you stay next to an AP, like 5 meters with no wall in between. 
• there are 3 Access poins, 1 centralized on each floor. 

[Rich R]

>  latest and recommanded versions of Mobility expresss as well as EWC.
Please state precise software version numbers?
ME should be 8.10.196.0 because it's the last available release but kind of irrelevant since you moved to EWC so what version of software were you using on the 9115?

Did you run your EWC config through Config Analyzer (link below) and rectify any errors and investigate any warnings?

What disconnect reason(s) did you see for affected clients in the debugs/RA traces?

[Leo Laohoo]

Bounce the radio of the APs. 

If this works, albeit temporarily, this could be CSCwj91255 (fixed in 17.12.4 APSP8).

[Rich R]

CSCwj91255 is also fixed in 17.12.5.
It should have been fixed in 17.15.3 too but it's not showing in bug tool Fixed versions or 17.15.3 release notes so might be an example of something that got missed from a release even though it's a sev 2 bug <facepalm> or they just haven't bothered to update the bug database (yet)... (a common problem recently)

[Rene Mueller]

That bug sounds like it matches my problem. I will update to 17.12.5. However I don't see the bug in the resolved issues within the release notes. 

[Rich R]

It is there in the release notes:
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-12/release-notes/rn-17-12-9800.html#resolved-caveats-for-cisco-ios-xe-17-12-5

And it's in the bug tool too:

Edit: But you're right it's missing from the EWC release notes!
I hope that's just because they've only listed the EWC specific bugs there.  I would expect that it also got all the same fixes as the main 9800 release though.  Worth testing anyway but you'd have to ask TAC to ask the BU if you want to be sure.  I'm pretty sure they're mostly built from the same code base with only a few EWC specific components which are different (well that was the whole idea of EWC) so I'd be very surprised if it isn't also fixed in EWC.

[Rene Mueller]

I checked release notes for 9115AXI AP

[Scott Fella]

Take the release note with a grain of salt.  Unless you really focus on bug scrubs or work with your Cisco SE, there are hidden bugs that are not published and or the notes may seem like it is your or not because not all versions may show as affected.  Bugs is why having a spare controller or in your case a spare EWC can be very helpful and you can test code versions before going to production and test versions for features and stability.  Upgrading/downgrading takes a few minutes and can help reduce the time of issues that can be resolved fast.