The Weirdest Wireless Issue Ever

[PaulRenda]

Setting: We use ZyXel equipment's throughout the school, specifically in the Training area we have two of these equipment's setup with PSA-WSK2 key and both with different channels settings, 6 and 9. I have swapped out these equipment's for new ones, I have changed them around, I have changed all the network cabling, I have changed the patching on the switches and wall. I have also changed from getting their IP from DHCP to manual.

Curiosity: This issue only seems to occur in the Training area, located on the far end of the building. Rest of the school great!

 

 

Weird Problem: After all the changes and trails I have done, I cannot get laptops to connect to the wireless. Actually they do connect, but they get the ! mark and a 169.* IP address. Turning them off and on about 50 times and with the Force on your side you eventually get them connect to the wireless. I mentioned laptops, because this only seems to happen to laptops with Windows on them, don't have any Linux laptops to try with. The curious thing, is that iPhones, iPads and MacBook Pro's easily connect to the wireless without an issue. Seems like I have a 'racist' wireless here (not that computers are races...). I have ran out of ideas. Any help would be appreciated.

 

Thank you.

 

Edited October 30, 2013 by PaulRenda

[Duke5A]

Are they all the same model laptop? Or more specifically the same model wireless chipset? You may have a driver issue.

[PaulRenda]

Hi Duke5A.

 

No, I have tried several different laptops, from Toshiba, HP to Lenovo's. The only thing they have in common is a Microsoft OS (Windows 7 and Windows 8).

Edited October 30, 2013 by PaulRenda

[neilmac]

DHCP is given through Data frames, and you can only send data frames once you associate to ann access point.

 

So, first of all check the logs and see if the client is being shown as associated.

 

Next, run wireshark on the wired portion of the network to trace the DHCP D-O-R-A process.

 

If you don't see the DHCP discover packet coming from the station on the wired, then you need to do a frame capture of the wifi.

 

This is not a particularly wild problem in the world of wifi, with the right tools and knowledge you can easily and quickly see where it's failing.

 

NM

[PaulRenda]

Thank Neil.

 

Well, this is a very wild problem for me, as in all my years of ICT, I have never seen it occur. I don't consider myself a specialist in wi-fi, hence asking for help.

 

I have installed Wireshark on the laptops with issues, but I can't make heads or tails of the data it is showing me. Is there something I should be looking for in particular?

[Netwacky87]

I noticed from the screenshots the QoS says VoIP...sounds logical (but sometimes IT isnt...) that your phones will connect (cuz its a phone) and your laptops wont....just a hunch?...

[psydii]

What does inssider tell you?

 

Are anyof your other AP's visable in the training area?

 

Can you connect to them?

 

Are the ipads and laptops connected to the same ssid?

 

 

How far away from the training area do you have to move the 'traing area ap' before you can get reliable connections for your laptops?

 

Are you running with the latest wireless drivers on your laptops?

 

Have your installed the hotfixed from here: http://support.microsoft.com/kb/2775511on both servers and client machines?

Edited November 7, 2013 by psydii

[White_Fi]

Just on a quick note, if those APs "close" i would move the AP on CH9 to CH11... 6 and 9 have some overlap and could cause adjacent channel interference

[PaulRenda]

Hi psydii,

 

All the AP's are visible. Laptops and iPads can connect to the AP's, but while the iPads(pods, phones) will get an IP address, the laptops will only get a 169.*.*.* IP address and fail to connect.

 

Yes, they are all connected to the same SSID, otherwise it would be easier to spot the problem.

 

Our laptops yes, but as you are well aware this is a Training Centre where lots of people bring their own devices and I cannot account for their driver updates.

 

 

Hi StuartWhite,

 

They are all on different channels, as I explained on my initial post.

[White_Fi]

Yes but channel 6 and 9 overlap by about 5MHz. There are 3 non-overlapping channels in the 2.4GHz band. They are 1, 6 and 11.

 

If the APs are on adjacent channels i.e 6 and 9 then there is a possibility there will be collisions in the air and re-transmission rates will be higher than usual with the end results being reduced data rates.

 

It is unlikely to be the cause of the issue here however only channels 1, 6 and 11 should be used (Unless you have Ruckus with channel fly on and clients support 802.11h - that's a different story) - Just noticed this and thought I'd advise

 

IEEE 802.11 - Wikipedia, the free encyclopedia