gwendes Posted January 10, 2007 Posted January 10, 2007 This is an ongoing problem that is about to drive me to insanity. I work in a training centre where we have 30 wireless laptops. Since I started working here in July there has always been the problem that some laptops just drop the connection and cannot find a domain controller. The only solution, albeit temporary, is to reconnect the laptop to the domain with a patch and reattach to the domain. I have recently upgraded every wireless card from Ralink 2500 chipset to the Intel 2200BG which has improved things slightly. This week, back feeling positive after xmas, I find we have eight laptops not connecting. I had started reattaching them this afternoon but if I have to keep doing this every couple of weeks I think early retirement might be the only option We connect to the main school site over a 1.2Gbps fibre - thinking that 30 laptops logging on together was too much for the DC at the other end I installed a DC into the switch here. We have an Aruba wireless switch and above 5 access points in the building.
alan-d Posted January 10, 2007 Posted January 10, 2007 Maybe adding 1 or 2 more access points may help. You don't say whether the laptops are used throughout the building or lumped together in one room.
plexer Posted January 10, 2007 Posted January 10, 2007 What security settings are you using one the laptop to connect to the access points? Ben
gwendes Posted January 10, 2007 Author Posted January 10, 2007 Maybe adding 1 or 2 more access points may help. You don't say whether the laptops are used throughout the building or lumped together in one room. In just one room. That room has an AP and there are another 3 or 4 that computers in that room can connect to. Before changing the cards I kept a log of which computers failed and it seemed to reoccur on the same laptops. What security settings are you using one the laptop to connect to the access points? Ben. The laptops all use WZC and WPA/TKIP PEAP The settings are fine as I can login (with cached creds) and the connection is established wirelessly with no issues. Only a user that has not been 'seen' by the DC will have a issue - until connection with a patch cable.
plexer Posted January 10, 2007 Posted January 10, 2007 Why not use machine authentication only rather than user that way the wireless connection is set up when the machine is preparing network connections and most of the time by the time the user is presented with a login screen the wireless is connected. Ben
alan-d Posted January 10, 2007 Posted January 10, 2007 Beat me to it plexer another option is to bridge the APs. Each AP will usually struggle with 10 connections - depending on the logon script. The laptop will then search for another AP and so on, eventually it gives up and says bugger it I can't find a DC. By bridging you increase the chance of the laptop finding a DC at the first attempt.
gwendes Posted January 12, 2007 Author Posted January 12, 2007 As I haven't got access to the PoE switch until Monday I'd like to try the machine authentication option. Is that done on the DC? I've never set that up before, can you point me in the right direction?
plexer Posted January 12, 2007 Posted January 12, 2007 Start Up group policy management console right click gpo containing your wireles policy and select edit. go to: Computer Configration Windows settings security settings wireless network policy right click on your policy and select properties preferred networks select the one you want click on edit go to ieee 802.1x tab make sure authenticate as a computer is the only one checked. change computer authentication dropdown to "computer only" Ben
gwendes Posted January 12, 2007 Author Posted January 12, 2007 I've done that - there wasn't an existing wireless policy in place. I noticed that there weren't any settings for WPA/TKIP PEAP so I've just removed the tick from WEP. Is this right?
plexer Posted January 12, 2007 Posted January 12, 2007 Depends on what security is being used by your access points etc... All though I've just re-read your original question and you say you have an aruba wireless switch am I right in thinking this is the device that actually controls the access to your wireless network? You must have to set things up via the aruba program but I don't know as I don't have one. Some on here does have an aruba setup though. Ben
gwendes Posted January 12, 2007 Author Posted January 12, 2007 mmm, that's what I'm not 100% on. It's not a system that I've setup or used - just inherited and the tech that knows the most about this is out today. He has said that the blame must lie with these laptops (Uniwill) - PDAs and other laptops in the school (Toshiba and Dell mainly) don't seem to have this problem. As I cannot pin it down to hardware or software in any way then I am inclined to borrow some power tools from technology and... well... massacre is a word that springs to mind! Wish that this wasn't one of those intermittant, unrepeatable problems. I'd love to blame the switch or access point over here and get Aruba in to sort it out but once a machine has dropped it fails to establish a connection with any of the other switches in the main building. All the way through this I've been convinced it's a Windows bug that prevents the laptop from even looking for a connection if it fails a certain number of times or the load is too high on the AP...
plexer Posted January 12, 2007 Posted January 12, 2007 What make and model laptops are they? Windows will only retry a dropped connection 3 times I think it is then you have to log off and possibly reboot the machine. There are some M$ guides on troubleshooting wireless with some debugging info too. Ben
gwendes Posted January 12, 2007 Author Posted January 12, 2007 They are Uniwill 259 chassis from Novatech. Other laptops around the site don't seem to have the same problem - much as I would like to blame ms. Rebooting doesn't help, you need to connect the laptop with a patch cable or admin with cached credentials needs to log in wirelessly and reattach the laptop to the domain. Then it's ok for a random amount of time.
plexer Posted January 12, 2007 Posted January 12, 2007 What wireless cards are in them and what access points are you using? Ben
gwendes Posted January 12, 2007 Author Posted January 12, 2007 Aruba AP 61 access points - 5 in this building. Usually 4 are visible from each room. The wireless cards have all just been upgraded from generic Ralink cards to Intel 2200BG in an attempt to solve this issue.
plexer Posted January 12, 2007 Posted January 12, 2007 Ah yes I see you said the cards in the first post sorry. I had an issue with a set of laptops that I had upgraded to G wireless using the 2200BG card and was nothing but problems if you google for 2200BG connection problems you should find loads of hits. In the end I changed all the cards for something else. I'm not saying it's what you've got just that I feel your pain. I believe the aruba software allows you to do a lot on the configuration of the clients do they run any aruba client app on them? Ben
gwendes Posted January 15, 2007 Author Posted January 15, 2007 I would be looking at changing the cards if they had originally been fitted with these Intel 2200BG but they were fitted with cards I was having issues with and the problems remain so I am trying to find the next step. This morning we have been looking through the switch setup and found two things that we're trying. The first is Pre-authentication and we've recalibrated the access points. My fingers are hurting from crossing them...
rob101 Posted January 16, 2007 Posted January 16, 2007 Gwendes i feel you pain and worse i feel we have 30 laptops in maths 30 in english and 30 in science and i have the same problems as you above i have tested all most every type of wireless card and found proxim cards to be the best so far but there very costly. We are running the 30 from 1 room in science the ap's are spread around the block in english and maths we have 2 aps in 1 room 1 is g and 1 is a this seems to work better but we still have many problems and tbh its driving me mad. It does not help when teachers go to other schools and see wireless working come back and say it should work here because it does in other scools. there are a few things i will try from this thred and tell you ho it goes. one qestion some one talked about machine authentication can you explaine this a little to me please? Cheers Rob
Quackers Posted January 16, 2007 Posted January 16, 2007 If you use Intel Wireless cards you should be able to enable "Pre logon connect" in the Intel Wireles Profile. This makes sure the wireless is connected and working before the logon screen appears. Only time we have the problem in this thread is when a pupil has turned the wireless off with the button on the laptop.
Ric_ Posted January 16, 2007 Posted January 16, 2007 I must admit that I am with Quackers here... the 2200BG chipset works great. i use Pre-Logon Connect with WPA2 and all is fine.
gwendes Posted January 16, 2007 Author Posted January 16, 2007 Pre-logon is definately on and wireless power is set to the highest. Hopefully today we will get round to reimaging all the laptops and this will lay the blame firmly on software but I'm at the point now where sending them to the 'Will it blend?' guy on YouTube would be by far the best option!
DMcCoy Posted January 16, 2007 Posted January 16, 2007 You need to download the latest drivers, which contain a fix for some domain issues. I spent weeks trying to fix a laptop at home so it would start the network before the domain, a driver update from intels site fixed it (some months later though). Pre logon connect doen't actually work either, it will still login without the domain. The biggest issue is that you end up missing the policies at boot.
gwendes Posted January 16, 2007 Author Posted January 16, 2007 I'm just making an image which will have the very latest drivers installed. Hopefully. *prays to the great spaghetti monster in the sky*
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