Wireless + CC4 = Help!!

[JustComm]

Hello edugeek, my names rob im a network engineer in need of advice from a higher power!

 

i'm currently in a primary school in kent that is running a CC4 network, the school has a 24-port belden wireless switch with 12 aerials, its a very nice bit of kit...

 

however they are also trying to run 150 laptops on an 802.11G network,

 

the laptops will not pickup an ip address from the DHCP when they are switched on (1 in 10 will, sometimes) yes before i switch them on i have checked the wireless cards are on and that im within close proximity to a wireless aerial.

 

i feel that the problem could be with the schools dhcp but my knoledge ends there, i only have enough brain power to configure the wireless switch and expect it to work, can anyone suggest a solution as to why the laptops are not picking up an ip address and a connection,

 

ps. hardwired i can log in as any user and manual connect to the wireless.

 

any information or guesswork will be greatly appreciated

[Michael]

It doesn't sound like DHCP Server is the problem as it works fine with wired workstations. If it was DHCP Server, then wired workstations wouldn't get an IP either.

 

I can't say I've ever heard of Belden, but I know of Belkin which sounds familiar. Anyway, back on topic, I would login to the Access Point (presumably using a browser) and make sure the IP configuration (IP of the AP, Subnet, Gateway and Primary DNS) are setup correctly. You also need to turn DHCP off on the AP.

 

If all this is correct, I would then temporarily turn off any security and with a laptop test whether it connects. If it does then great, proceed to turn on security. I'd recommend you use WPA/WPA2. Then proceed to test again and all should be fine, but please remember that all APs have a limit to how many workstations they can handle at once. Typically this is upto 15 devices.

 

It's also good practice to trim down profiles as much as possible and optimise machines to the max so logon times are kept to a minimum.

[nicholab]

Vlan might be require to break up the broadcast domain.

[mjs_mjs]

we have the same issue here. to make sure wireless is working - get a un cc4'd laptop with wifi and go walkies around the place, do a few reboots... this will tell you if your issue is cc4 or wireless... it's unlikely DHCP is the issue.

[JustComm]

thank you for your quick reply, but i think i should explain the hardware a little more

 

the Belden wireless switch is essentially the only smart piece of technology, its a 24-port switch that works as the access point, it then has multiple aerials wired to it using Cat5e which run off to different areas of the school using PoE

 

so far i have updated the wireless card drivers on the laptops, which has improved the latops slightly, however its very..... luck based on wether the laptops will connect, the wireless is encrypted with a WEP128 i think (i have no knoledge on encryptions this was setup by the school)

[Michael]

WEP is OK, but it's certainly weaker than WPA. It sounds interesting what you describe, but I'm curious how you configure the wireless channels. Essentially there are 3 channels you should use - 1, 6 and 11. Hypothetically, if you had two APs broadcasting the same SSID and on the same channel close by, this would create a lot of problems.

[JustComm]

WEP is OK, but it's certainly weaker than WPA. It sounds interesting what you describe, but I'm curious how you configure the wireless channels. Essentially there are 3 channels you should use - 1, 6 and 11. Hypothetically, if you had two APs broadcasting the same SSID and on the same channel close by, this would create a lot of problems.

 

the wireless network is broadcasting one ESSID on channel 1 at 802.11g, the technology used by belden switches was "cloned" from a company called Extricom, they call it a "blanket coverage" because the basics of there wireless systems are tottaly different to how standard wireless APs work, for your own interest if you have 2 minute watch this video and it will show u how there system works

 

[ame=http://www.youtube.com/watch?v=1qw7FuAOo_g]YouTube - Extricom WLAN In Action[/ame]

[JustComm]

just a quick note ive just been told that the school is running CC3!!

i don't know what difference this makes to the wireless side of things =o

[SteveT]

Is it getting stuck on the "Acquiring Network Address" stage? Can they log-on if you give them a fixed IP address?

[JustComm]

Is it getting stuck on the "Acquiring Network Address" stage? Can they log-on if you give them a fixed IP address?

 

i have created a new ESSID to use as a test with no encryption and the laptops and i have tested 8 laptops which have all happily connected, they all have internet access and can see the shared network drives,

 

my colleague has tried to use fixed ip addresses and has had no success.

[Michael]

i have created a new ESSID to use as a test with no encryption and the laptops and i have tested 8 laptops which have all happily connected, they all have internet access and can see the shared network drives,

 

Thanks for the video. It looks/works how I would expect it to apart from the channel configuration. Usually you'd have seperate channels for each AP so they don't overlap.

 

It's good they work with no security, so at least you know the AP works. I suspect they're not getting an IP due to an incorrect security configuration. I would try and re-create the original SSID so all laptops should then connect instantly or create a new secure SSID, but you'll have to update each laptop manually.

[JustComm]

Thanks for the video. It looks/works how I would expect it to apart from the channel configuration. Usually you'd have seperate channels for each AP so they don't overlap.

 

It's good they work with no security, so at least you know the AP works. I suspect they're not getting an IP due to an incorrect security configuration. I would try and re-create the original SSID so all laptops should then connect instantly or create a new secure SSID, but you'll have to update each laptop manually.

 

yes i agree, im currently adding an encription to the TEST essid i created, ive used a simple WPA-personal encryption (following advice from a 3rd party)

[gjdb]

If you WLAN NIC`s are from Intel, you could try to enable Connect before registration/login, this is not enabled by default.

This can be found in Configuration - Software - Intel PROSet/Wireless - Modify/Remove

 

An other option could be: DisableDHCPMediaSense.

Description: How to disable the Media Sensing feature for TCP/IP in Windows

 

To check your wireless coverage and channel overlap you could use: Ekahau HeatMapper - The Free Wi-Fi Coverage Mapping Site Survey Tool

[JustComm]

If you WLAN NIC`s are from Intel, you could try to enable Connect before registration/login, this is not enabled by default.

This can be found in Configuration - Software - Intel PROSet/Wireless - Modify/Remove

 

An other option could be: DisableDHCPMediaSense.

Description: How to disable the Media Sensing feature for TCP/IP in Windows

 

To check your wireless coverage and channel overlap you could use: Ekahau HeatMapper - The Free Wi-Fi Coverage Mapping Site Survey Tool

 

 

ahhh, now the expert on the phone mentioned connect before login, but he said that was found on the server, are you talking about a setting on the individual laptops or the server, its a windows03 RM server, running cc3 as i corrected myself earlier NOT cc4

[mjs_mjs]

we had this issue with cc3 before going cc4

 

they would connect without any encription; but not with it.

 

 

a solution;

plug in (to net)

log on as administrator,

add the wireless,

set it to infrustructure only,

and not to use any other networks than thoes added,

log off unplug and test.

 

this worked for us on cc3 with d-link accesspoints (5 or 6) over 50 laptops, using WPA-PSK, TKIP encription.

 

hope this helps.

 

(they took 3 or 4 mins after booting up to get their IP's over wireless tho)

[mjs_mjs]

the wireless network is broadcasting one ESSID on channel 1 at 802.11g, the technology used by belden switches was "cloned" from a company called Extricom, they call it a "blanket coverage" because the basics of there wireless systems are tottaly different to how standard wireless APs work, for your own interest if you have 2 minute watch this video and it will show u how there system works

 

 

nice bit of kit.... wish i had one of thoes - how much did it cost if you dont mind me asking?

[JustComm]

send an email to [email protected] just asking about wireless and the firm will send you everything relevant

 

just communications only sell one wireless system because we know that this is the gear that works