Folder redirected folders sometimes not appearing on WiFi

[OllyM]

Hi

 

We have several class sets of laptops which the kids use for various functions. Mostly they log on as the function (ie username: spellingtest etc) and get shown the right icons on the desktop for that thing via folder redirection.

 

All the laptops are solely used on WiFi as the ICT suite here also serves several other functions and it's easy to put the laptops to one side.

 

Every now and again several laptops (not always the same ones) will fail to show any of the folder redirected icons on the desktop after a child logs on and complain that they cant map certain network drives. Normally we log out and back on again and that tends to fix it. Each time this happens the event log shows entries relating to no domain controller being found.

 

My guess is that the kids are able to log on before the WiFi has finished connecting, but we've set a GPO for the computers to wait for the network before logging on, we've turned off fast logon (that is we've enabled synchronous policies). I've also forced folder redirection to be used on slow links in case the AP was flooded at the time, but looking at the logs the link speed is never less than about 80Mbps

 

Anyone got anything else we can try? Any ideas how we can prevent this happening without using a cable?

 

Olly

[DavetheITguy]

Are you using Radius ?

[OllyM]

Nope. Nothing so fancy, just AD for the laptop logins and a pre-shared key for the wifi.

[Patrick]

With login issues with wifi and speed, i've some success with this GPO. Admittedly it was for software installation over wifi that was working fine over wired. Worth a try maybe?

 

Computer Configuration > Policies > Administrative Templates > System >Group Policy > Startup Policy Processing Wait Time

 

The default time is 60 sec i think but i often use 10. It may or may not help, but worth a try to narrow it down.

[mistersparky]

Some questions on the WiFi front:

• Does the problem happen more often when using the laptops in the same location, or when using larger numbers of laptops?
  
• Do you have good WiFi coverage around the building?
  
• What have you done to avoid overlapping 2.4GHz channels (have you had some kind of WiFi survey done, manual settings, or is it managed by the WLC?)
  
• How much is connecting via 802.11b/g? I've seen some strange situations where 802.11b/g/2.4Ghz n devices with faults/poor signal can drop the bandwidth across the SSID (I think a common workaround for this is to data rates than 11Mb/s for the 2.4 GHz 802.11b/g/n networks).
  

 

I had a lot of problems a few years ago with a situation not to dissimilar to this that, much to my frustration, I was unable to resolve. Some of the details of this eppisode can be found here: http://www.edugeek.net/forums/windows-server-2008-r2/108941-roaming-profie-oddities.html. The biggest takeaway I took from all of this is a lot of functionality one would associated with a managed Windows desktop environment (roaming profiles, folder redirection, network drives, other general GPO policies, etc.) simply don't work well over low bandwidth, poor signal WiFi networks. It might be somewhat stating the obvious, but I think it would be good to start from checking the WiFi network. Is coverage as good as it can be, are there any settings or tweaks you can put in place to improve the network? Is it possible to get any users to connect over wired connections?

Edited November 11, 2016 by mistersparky

[OllyM]

Thanks all

 

The wifi coverage in general isn't bad. Certainly in the ICT suite the coverage is fine, and it's only in that room that the computers are being used. Typically when the computers are used, they are all used together so that about 10 or more kids will log on at once. The slow link state at this time appears fine in that the event logs show that the link speed is around 100mbps or so each time.

 

I've moved the AP to 5Ghz N only, as the laptops are fine with this, and the channel it's on is free. I'll see whether this might solve the problem.

 

I agree with you mistersparky in that I think a lot of the features required don't "play nice" with wifi in general. I'd love to get a wired connection to each one but the room has multiple uses and the desks are floating "pods" so it's hard to run a wire to each one without making it all look a bit s***y.

[OllyM]

With login issues with wifi and speed, i've some success with this GPO. Admittedly it was for software installation over wifi that was working fine over wired. Worth a try maybe?

 

Computer Configuration > Policies > Administrative Templates > System >Group Policy > Startup Policy Processing Wait Time

 

The default time is 60 sec i think but i often use 10. It may or may not help, but worth a try to narrow it down.

Thanks Patrick.

 

Shouldn't this value *increase* not decrease as it's the time that the system waits before processing GPOs, and I want the system to wait for longer so that it has a chance to connect?

 

As per this KB I've increased it to 100, though it was already on 60.

 

https://support.microsoft.com/en-gb/kb/2421599

[Duke5A]

I had similar issues with wireless on student notebooks and I never was able to nail it down. I tried all those GPO settings. The original issue was our VB login script wasn't running anymore on wireless devices. In the end I gave up and transitioned everything over to GPP and used item level targeting to filter who gets what. Never looked back.