wifi in ubuntu

What's your wifi chipset ?

And what do you see in /var/log/syslog?

I've seen similar behaviour before when the Broadcom drivers go crappy, and usually I'll see a recurring series of related messages in syslog that shows at least what's going on...

Look in syslog as well as letting us know what wifi chipset you have.

Crap... clicked the wrong button... that's not necessarily an answer...

However, I'll add this much too:

When I saw this behaviour (on my netbook using a Broadcom BCM4312 chipset) the only fix would be to reboot. Even unloading and reloading the drivers (I was using the wl driver, IIRC) failed to reset the hardware.

Usually this would happen after the system suspended and awoke for me, however, I DID notice it occasionally when just working.

Hi,

Please first connect your wired network adapter to the wireless router using an ethernet cable (also known as a LAN cable).

In order to gather essential troubleshooting information about your wireless card, please follow this procedure:

Step 1: Open Terminal from "Applications->Accessories->Terminal"

Step 2: Please copy-paste the following command from the https://answers.launchpad.net/ubuntu website in Firefox into the Linux Terminal. Do NOT copy-paste from the Email message into the Terminal, as that will only copy PART of the command. The command STARTS with the word sudo and ENDS with the word lsmod. So please copy-paste the ENTIRE command below from Firefox into a Terminal, press <enter>, then enter password when sudo asks for password, then press enter again.

Tip: If you have a wheel mouse or 3 button mouse you do not need to type commands into the Terminal. Highlight the command written on the page. Move your cursor anywhere in the Terminal and press the wheel or middle button. Automatic Copy and paste! No spelling mistakes! No Typos! No other errors!

sudo apt-get update; sudo apt-get install hwinfo grep; sudo lshw -C network; rfkill list; sudo iwlist scanning; cat /etc/network/interfaces; cat /etc/lsb-release; lspci -nn; lsusb; sudo lshw -short; uname -a; dmesg | egrep 'acx|at76|ath|b43|bcm|CX|eth|ipw|irmware|isl|lbtf|orinoco|ndiswrapper|NPE|ound|p54|prism|rtl|rt2|rt3|rt6|rt7|usb|witch|wl'; iwconfig; cat /etc/modprobe.d/* | egrep 'acx|at76|ath|b43|bcm|CX|eth|ipw|irmware|isl|lbtf|orinoco|ndiswrapper|NPE|p54|prism|rtl|rt2|rt3|rt6|rt7|witch|wl'; sudo hwinfo --netcard ; cat /var/lib/NetworkManager/NetworkManager.state; sudo lsmod

Step 3: Please post results (copy/paste terminal output) on this thread. The troubleshooters here need to see the full Terminal output from running the above command.

Step 4: Please also specify the exact model and make of your PC (if known) on this thread

Regards,

Mark