[Ubuntu Chicago] Riddle me this

Chad Sutton chadarius at gmail.com
Sun Nov 11 20:42:20 GMT 2007

Freddy Martinez wrote:
> Are their wireless drivers enables?
The two things that I do all the time to screw up my wireless setup is...

1. Forget that I've turned off the wireless on the laptop with the switch.
How to resolve? Turn on the wireless networking switch! On Dells this is 
usually FN+F2.

2. Tried to set some network card setting manually which makes 
knetworkmanager ignore that network card and stop working.
For this I run the following commands to make sure everything is working 
properly. This assumes that your wireless card is eth1 (with eth0 being 
the wired network card).

If your /etc/network/interfaces file has anything in it besides the lo 
interface then you should remark it out. This will allow your graphical 
network card manager. If your drivers are all installed and working than 
this will fix it pretty quickly.

sudo nano -w /etc/network/interfaces

This is my file. You can see where I've remarked out all the network 
card lines with a #.
---Begin File---
auto lo
iface lo inet loopback

#iface eth0 inet dhcp
#auto eth0

#iface eth1 inet dhcp
#auto eth1
---End File---

If that doesn't work than there may be a problem with your driver.  In 
Gutsy I finally was able to ditch ndiswrapper with my Broadcom 43xx 
wireless card. To check whether my driver is loaded I run the following 

lsmod |grep bcm43xx

Which returns:
bcm43xx               127336  0
ieee80211softmac       31360  1 bcm43xx
ieee80211              35656  2 bcm43xx,ieee80211softmac

I know its loaded when I see some lines returned. Your network card 
driver may be different. For instance if your laptop is using the Intel 
Centrio chip set it would be ipw2200 instead of bcm43xx. If you are 
using NDISWrapper than ndiswrapper is the driver you need to load.

If the driver isn't loaded (no lines are returned from the last 
command), try loading it manually by running the following command:

sudo modprobe bcm43xx

Again, replace the network card driver with your specific driver.

Once you know your driver is loaded, you can check to see if your 
wireless card can see networks. Do do this, run the following command:

iwlist eth1 scan |grep ESSID

This will return a list of all the wireless networks it can see. If its 
not working the list will be blank. You can also get rid of the "|grep 
ESSID" part of the command to see all the other detailed information.

If you can see networks with the scan than your driver is loaded and 

Chad Sutton
csutton at chadarius.com

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