ibm t41 wireless problem with WPA-PSK

I work at a helpdesk and constantly prepare new computers for employees to use. We have a protected wireless network, which is set up with WPA-PSK authentication and TKIP data encryption. When I set up computers to use the wireless network, there are usually no problems at all. We mostly use Dell products, but were given several IBM ThinkPad T40 and T41 laptops. When I set those up to use our wireless network, they behaved very strangely. The wireless would work on some laptops but not on others. Then a half hour later, the ones that were working stopped working and the ones that weren't working started working. Later on, none of them would work. A little later on, all of them would work. It was very, very odd. I experimented with a couple of the laptops. I updated the BIOS and the embedded control, but that didn't help. The laptops were set up using an image, so I thought maybe there was a problem with our image. However, after a fresh install of Windows XP SP3, the problem remained. Then I thought that the wireless cards might not be compatible with SP3, so I did a fresh install of Windows XP SP2, but the problem remained. I've installed the latest drivers and played around in the BIOS, but nothing helps. It's such an odd problem, and I'm not sure what to do next. Some of the laptops have "Cisco Systems PCI Wireless LAN Adapter" cards and others have "Gigabyte GN-WI01GS mini PCI WLAN Card(Turbo)" cards, so I'm guessing the problem is with the laptops themselves. Any thoughts?

 

You seem to have ruled out the imaging issue by installing a fresh copy of Windows and getting the same problem, but you might want to make sure they don't all have the same computer name. It would cause conflicts if they did.

Also, how large is your DHCP pool? If it's restricted, to say 30 IPs, and you've got 50 computers at your location, you'd end up with 20 systems that couldn't get online because they wouldn't be allowed an IP. If you took a couple offline and their IP leases expired, then the next couple of laptops you turned on would get them. Just a thought.

You might also want to make sure the laptops weren't imaged with a static IP address. If they were all assigned something like 192.168.1.100, and they all came on the network at once, you'd likely see them throw fits about it.

Maybe try isolating one system and watch it. Turn all the others off, setup just one with a fresh install of Windows and a driver you know has worked. Connect it to the network and see how long it takes for it to drop the connection. Check its IP address, ping the router, ping an outside site, check its signal strength, let Windows manage the connection, disconnect and reconnect manually, etc. Try to diagnose just one, then work from there.

 

i have a T41 that exhibits this same problem so you are not alone. I don't have a solution for windows specifically but interestingly the wifi works flawlessly in ubuntu. same system, same hardware but perfect wifi in linux and flaky at best in windows.

i myself have tried the following to no avail: no encryption, wep, wpa, wpa 2, pre-shared key, non-pre-shared key, all channels from 1 to 11, aes, tkip, static ip, dynamic ip and countless other things. i swear these notebooks just refuse to work. >: |

 

Okay, so perfect Linux performance. That doesn't leave much to fault with the problem, except just Windows in general. Which wireless card is in yours, Smelly Cat?

 

The exact labeling in device manager is: Intel PRO/Wireless 2100 3b Mini PCI adapter.

other than this one fault i must say these thinkpads are stellar notebooks. my t41 is 7 years old and still going strong!

 

So that's three totally different wireless cards all exhibiting the same problem. The only uniting factor is that it happens in Windows XP. Maybe there's a problem with the chipset driver? Not sure why it would effect wireless performance, but it's the first thing that comes to mind that should be the same on all these laptops.