27.6 - PSK Issues?

[NolanHerring]

Recently upgraded two warehouses from 25.13 and 26.8.1, to 27.6  (MR33 for one, MR42 for the other). The 25.13 has been running there for a looooong time, no issues.  26.8.1 is a newer site so 25.13 was never an option during installation.

Ever since the upgrade at both sites, Zebra scanners have been having connection issues on their wireless SSID (WPA2/PSK). 

Been trying to troubleshoot the issue but of course its difficult to do this remote. Scanner just 'loses' connection and won't connect back for anywhere from 1 to 4 minutes. Very odd, because wireless is available, plenty of coverage for the AP right above it and clients are on that same AP.

Curious if anyone else has ran into issues with 27.6 like this. Starting to contemplate rolling back the update.

[GIdenJoe]

Hmm, there's no easy way you can troubleshoot this remotely.

Since AP's only capture incoming frames you can't see what the AP is sending out.

You can only hope that another AP is close enough to match the channel and try an OTA using the other AP.

You'll have to see what's going on.
Is the client probing and on the correct channels?
Are the AP's responding to the probe?
Does the client in fact connect but get kicked off or refused association?

etc...

[NolanHerring]

Yeah its a tough situation to tshoot.

I shipped a Macbook to the site to use that as a capture tool.

AP is right above the client and it will be connected but then just 'disconnect' and can't connect for X minutes. There are other AP's also nearby that provide good secondary coverage as well. So there are plenty of chances to reconnect, but also no reason to lose connection to begin with.

One thing I see in Wireless Health is authentication failures, but this has pretty much always been an issue and i know 27.6 was supposed to have fixed the false positives for that reporting, not sure if thats true or not. 

[jmoake]

when you look at the "Network Wide" then "clients" then click on the particular client and finally on event log, are you seeing disconnects and reconnects corresponding to the times of loss of connectivity to the device?   

[NolanHerring]

Unfortunately, trying to troubleshoot this issue is very difficult when I'm not physically at the location.

I've actually upgraded several warehouse sites to 27.6, they all use Zebra scanners, and every single one of them has been having non-stop issues with connectivity on the scanners every since upgrading, so I'm rolling back to 25.13 (been running for over a year on this code no issues)

I don't care what the firmware version is, I only care that it's stable.

[NolanHerring]

My scanner random disconnect issues started at several warehouses the moment 27.6 was pushed.

So after not being able to be onsite at the several warehouse locations, and trying to work with onsite to get a packet capture (unsuccessful), I ended up rolling back from 27.6 to 25.13 at one site and 26.8.1 at the other. 

Several days have passed, and magically no more issues.   >.<

This is a real bummer, as I was really hoping to make 27.6 the new stable code.  And not being able to get a valid packet capture means Meraki support won't be able to do anything about it, so I have to basically avoid 27.X train for as long as I can at this point. 

Hopefully someone else will run into the issue and also be physically onsite to be able to capture the issue first-hand so they can get a fix.

[GIdenJoe]

I'm really curious where it goes wrong then.

Clients who refuse to connect at some time, or AP's failing to give them an AID.  Or some failure in the 4way handshake.

It's difficult to troubleshoot since the AP's can only capture traffic from clients or other clients that it receives.
It would be handy if there would be a way to have the AP's do intelligent capture like in the catalyst world so you can have each assoc and roam on record and have the state machine in a sort of debug log.

[LukeTownsend]

Good afternoon all, just checking if anyone moved on to the 28... release? Currently switching from Cisco vWLC's to Meraki and this was my first experience of Meraki AP's ... Zebra connectivity chaos.

[cmr]

@LukeTownsend we have run over a hundred APs on the 28 release train for months and it has been stable.

[MatthewDevis]

Thanks @cmr , What 28 release have you been using? We were on 28.6 on which the dropouts were experienced, rolling back to 26.8.1, as suggested in this thread, restored the zebra devices wireless stability.

[NolanHerring]

Upgraded finally to 28.6 and once again, running into stability issues with the scanners. Having to roll back.

[cmr]

Currently we are on 28.6, but used all versions without issues.  We did briefly see the dropouts you mention, but those stopped about 4 weeks ago, we then got one more a couple of weeks ago and all good since then.