I have a Dell XPS L702x Laptop and the wireless is dodgy in Ubuntu 11.04. By Dodgy I mean it drops out and doesn’t automatically connect very often especially when a Ethernet cable is unplugged. It seems the problem is that Ubuntu doesn’t get on well with wireless-N (perhaps the driver is buggy?). I fixed it by disabling wireless N (but leaving G working):
First check to see that b, g and n is enabled:
wlan0 IEEE 802.11bgn ESSID:"WKIXNTOM"
wlan0 IEEE 802.11bg ESSID:"WKIXNTOM"
To disable Wireless N, create a file called
/etc/modprobe.d/iwlagn.conf and put the disable incarnation in it:
> sudo vi /etc/modprobe.d/iwlagn.conf
options iwlagn 11n_disable50=1 11n_disable=1
Restart the computer to finish.
I agree this isn’t a ideal solution (to say the least!), but it’ll do for now.
Update after 2 months: Wireless has been reliable and steady since making the above change.
Update (15/Oct/11): This “hack” is a disaster for Ubuntu 11.10 Oneiric Ocelot, it causes Wireless to fail to load. Be sure to remove the
/etc/modprobe.d/iwlagn.conf file when upgrading to Ubuntu 11.10. I found this issue the hard way: askubuntu question.