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Professional Discussions => Wireless => Topic started by: fsck on December 26, 2016, 01:15:09 PM

Title: Device WiFi Issue
Post by: fsck on December 26, 2016, 01:15:09 PM
For the last week or so, I've had an issue with my wireless.  For whatever reason my IOS devices (ipads and iphones) keep dropping connection.  Once I disable and enable the wireless on the device, I'm able to connect again.  But then it's really slow, yet my laptops are connecting and have no issues.  I have no idea how to go about troubleshooting this issue.

So far I've tried rebooting the devices, making sure they're updated and kept them within close range.  How would you go about troubleshooting an issue like this?  I want to download a wifi scanner, but that will tell me the channels they are connected too so not sure if that will help.  No changes have been made to the wifi, so it was working before.
Title: Re: Device WiFi Issue
Post by: SimonV on December 27, 2016, 03:20:59 AM
What sort of wireless setup do you have? Standalone or Controller-based? What are the security settings, preshared key or dot1x? 

Title: Re: Device WiFi Issue
Post by: fsck on December 27, 2016, 12:43:01 PM
This particular setup is a standalone setup.  I'm using preshared key.  I'm using a Cisco Aironet 1041 AP.
Title: Re: Device WiFi Issue
Post by: SimonV on December 28, 2016, 02:31:39 AM
Anything in the syslogs about deauthentication or other reason why the devices leave the bssid?

It's usually some iOS update on the Apple devices imho :)
Title: Re: Device WiFi Issue
Post by: deanwebb on December 28, 2016, 09:27:23 AM
Quote from: SimonV on December 28, 2016, 02:31:39 AM
Anything in the syslogs about deauthentication or other reason why the devices leave the bssid?

It's usually some iOS update on the Apple devices imho :)

We had a similar issue at work, iOS update was what broke things and then, 2 weeks later, what suddenly fixed them.

If you want just a fix, call Apple and see if they can push an update faster, maybe.

If you want to use this as a learning opportunity, get your wireshark fired up and see what the captures show. Look for packets sent by the AP that are unanswered by the iOS device, resulting in a device not responding sort of error. Also check what authentication method you're using (PEAP, EAP-FAST, etc.)
Title: Re: Device WiFi Issue
Post by: fsck on January 06, 2017, 06:49:08 PM
Quote from: SimonV on December 28, 2016, 02:31:39 AM
Anything in the syslogs about deauthentication or other reason why the devices leave the bssid?

It's usually some iOS update on the Apple devices imho :)
Wow! The syslogs on the AP are horrific!  First of all all the logs are from a long time ago.  I don't understand why they aren't the latest logs, and how I don't have options to view the latest logs.  Unless I'm completely blind.

I've noticed to fix the issue on the iPads, I simply just turn off WiFi, and turn it back on.  Then I'm good for about 15 to 20min.
Title: Re: Device WiFi Issue
Post by: deanwebb on January 07, 2017, 10:18:49 AM
This is perfect with your avatar:

:itcrowd:
Title: Re: Device WiFi Issue
Post by: SimonV on January 07, 2017, 10:30:55 AM
Quote from: fsck on January 06, 2017, 06:49:08 PM
First of all all the logs are from a long time ago.  I don't understand why they aren't the latest logs, and how I don't have options to view the latest logs.  Unless I'm completely blind.

Are you sure the clock is set correctly? :)
Title: Re: Device WiFi Issue
Post by: fsck on January 08, 2017, 05:15:04 PM
Oh geez.  I just feel stupid now.  I didn't see an option in the GUI to set the time, so I never did it.  But I consoled into the AP and configured the correct time.  This might even cause some of the issues I am having.  The date was set for April 8 2003. :(

Now I can see what the logs say with the correct time, or maybe this might of fixed my issue.  I am sure an incorrect time/date sync could cause issues.
Title: Re: Device WiFi Issue
Post by: deanwebb on January 09, 2017, 10:33:34 AM
Quote from: fsck on January 08, 2017, 05:15:04 PM
Oh geez.  I just feel stupid now.  I didn't see an option in the GUI to set the time, so I never did it.  But I consoled into the AP and configured the correct time.  This might even cause some of the issues I am having.  The date was set for April 8 2003. :(

Now I can see what the logs say with the correct time, or maybe this might of fixed my issue.  I am sure an incorrect time/date sync could cause issues.

Don't feel like too much of a turnip. Setting time is something we forget to do quite often and, as you say, it can cause issues quite often, especially with certificates and security.
Title: Re: Device WiFi Issue
Post by: LynK on January 10, 2017, 08:44:06 AM
Time is essential in A LOT of wireless functionality. ALWAYS check the time on a controller
Title: Re: Device WiFi Issue
Post by: fsck on January 15, 2017, 04:31:10 AM
I finally got some log messages with the correct time/date.

WARNING: Packet to client a4b8.d844.6a21 reached max retries, removing the client.
INFORMATION: Interface Dot11Radio1, Deauthenticating Station a4b8.d844.6a21 Reason: Previous authentication no longer valid


I see these error messages for two of my Apple devices, both of which disconnect from the network.  I know they have the correct credentials and password for the network, so not sure why it's saying previous authentication no longer valid. I read online that a possible fix would be to disable the Aironet extensions, which I believe is used when you have multiple AP's and it decides which AP is best to connect too.
Title: Re: Device WiFi Issue
Post by: icecream-guy on January 16, 2017, 06:29:54 AM
Quote from: fsck on January 15, 2017, 04:31:10 AM
I finally got some log messages with the correct time/date.

WARNING: Packet to client a4b8.d844.6a21 reached max retries, removing the client.
INFORMATION: Interface Dot11Radio1, Deauthenticating Station a4b8.d844.6a21 Reason: Previous authentication no longer valid


I see these error messages for two of my Apple devices, both of which disconnect from the network.  I know they have the correct credentials and password for the network, so not sure why it's saying previous authentication no longer valid. I read online that a possible fix would be to disable the Aironet extensions, which I believe is used when you have multiple AP's and it decides which AP is best to connect too.

https://supportforums.cisco.com/discussion/10626961/packet-client-x-reached-max-retries-removing-client

says:


Hello!

I have found this problem too. The MAC-address is from Macbook.

Packet to client xxxx.xxxx.xxxx reached max retries, removing the client

I solved it via:

interface Dot11Radio0

rts threshold 512

rts retries 128


that was just the first hit.. google "Packet to client reached max retries, removing the client"
Title: Re: Device WiFi Issue
Post by: fsck on January 17, 2017, 02:16:33 AM
Yes, I found that too and tried it but still same result.  Client is still dropping and error continues to reappear.

I did Google the issue before posting.
Title: Re: Device WiFi Issue
Post by: SimonV on January 17, 2017, 02:40:05 AM
I vaguely remember similar problems on our standalone APs but they have all been migrated since. Don't even know if we fixed it. But if it's only with Apple devices, it sounds like they have driver issues.

Is this WPA2/AES?
Title: Re: Device WiFi Issue
Post by: wintermute000 on January 17, 2017, 06:40:15 AM
anything to do with IOS (see what I did there) MAC address randomisation? wild guess
Title: Re: Device WiFi Issue
Post by: deanwebb on January 17, 2017, 11:19:27 AM
Quote from: wintermute000 on January 17, 2017, 06:40:15 AM
anything to do with IOS (see what I did there) MAC address randomisation? wild guess

I HATE APPLE DEVICES RANDOMIZING THEIR STOOPID MAC ADDRESSES

:frustration:

So, yes, check that.
Title: Re: Device WiFi Issue
Post by: fsck on January 20, 2017, 11:19:00 PM
So looks like the configuration change might of fixed the issue.  I haven't had any wireless issues all week.
Title: Re: Device WiFi Issue
Post by: deanwebb on January 21, 2017, 08:55:40 AM
Quote from: fsck on January 20, 2017, 11:19:00 PM
So looks like the configuration change might of fixed the issue.  I haven't had any wireless issues all week.

That's always a good thing to say. But, since we always get intermittent issues, we always hesitate to close out that ticket 100%... or, we're not at all surprised when that ticket gets reopened.
Title: Re: Device WiFi Issue
Post by: Dieselboy on January 28, 2017, 12:19:47 PM
Okay a few points:

1. what channel are you using?


2. Open a wifi inspector on a device where you need wifi and take a screenshot of the wifi networks listed, their channels and their signal strength and post it here.


3. your AP is a 1041? I've never heard of that model but sounds like it pre-dates the 1131. So my guess is small CPU and 2.4GHz only. So, you will need to use WPA1 (not wpa2) and make sure you're on the least used channel, and only pick channels 1, 3 or 11. Those a

Your log message: WARNING: Packet to client a4b8.d844.6a21 reached max retries, removing the client.
this will be shown if:
a) your device is connected, and then goes out of range permanently. OR
b) your device is powered down (like a laptop being closed)
Basically means what the log says, the AP has a packet and tried endlessly to send that packet to the wifi client and never got any ACK back.  So, can be a bit misleading. I was chasing this log for a little while and was advised by TAC of the above. In the end, we had a number of issues:

1. extremely poor wifi AP placement (someone placed it on one corner of the office, behind the printer)
2. Extreme interference (the printer was broadcasting an access point SSID for wifi printing, grrrrrr!)
3. interference from other AP's
4. Interference from metal walls, structures and metal file cabinet!

When I got to site for the first time I mounted the AP's on the ceiling, central to the office floor, mounted a 2nd AP which shared the load, and turned off the printer's AP. Then someone turned it on again so I thought may be I never turned it off so I turned it off again. Then reports came in of poor wifi, so I found the printer AP was on again. So I turned it off a third time, and changed the password for the printer and locked it down. No more wifi problems for ages but did have a complaint that a few people couldnt print wirelessly. So just educted them how to print.

No more issues since then.
Title: Re: Device WiFi Issue
Post by: Dieselboy on January 28, 2017, 12:20:43 PM
Quote from: fsck on January 20, 2017, 11:19:00 PM
So looks like the configuration change might of fixed the issue.  I haven't had any wireless issues all week.

That's great!  :rock:

If issues come back, see my last post ;)

The funny thing about wifi is that it's completely environmental :)
Title: Re: Device WiFi Issue
Post by: SimonV on January 30, 2017, 02:35:01 AM
Quote from: Dieselboy on January 28, 2017, 12:19:47 PM
and only pick channels 1, 3 or 11.

Is that how you roll down under or have you made a typo? :)