[Ubuntu] Wireless stop working after upgrade

If wireless fail to work after upgrade, be sure to use lspci | grep network to look for your wireless device and include this info when you post online for help.

If you're using Broadcom BCM4312 (full name: "Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)") same as mine, then you probably could easily fix by installing the following:

sudo apt-get install firmware-b43-installer b43-fwcutter

or try another one if the above doesn't work:

sudo apt-get install broadcom-sta-common

You're adviced to reboot your system, but before that you may try:

1. off & on your wireless device, it may work straight away without system reboot.
2. run command modprobe b43

If you choose to reboot and the wireless device doesn't start, try modprobe b43. To autoload the device at startup, edit /etc/modules, add "b43" to the list. That should load it during startup.

Good luck!

[Ubuntu] Wireless not working when on battery

If you have read my previous post How to release/renew IP when dhclient doesn't work, but you still unable to use your wireless when running your laptop on battery mode, then it could have something to do with the power management in Ubuntu.

The symptom you might get is:

1. the wireless IP cannot be renew/release
2. the wireless connection is up, but you can ping local or internet
3. the wireless takes forever to get an IP from your router

The reason behind is when you're on battery, Ubuntu will activate power saving on your wireless device. This made the device cannot function properly. In this case my wireless device is:

"Broadcom Corporation" "BCM4312 802.11b/g LP-PHY" -r01 "Foxconn International, Inc." "T77H030.00 Wireless Mini PCIe Card"

If you are asking for help, you can identify your network controller by enter this command in terminal (special thanks to Serendah Linux from Ubuntu Malaysia LoCo Team to provide this command):

lspci -mm | grep Network | sed 's/.*"Network controller" //'

There are some solution that propose to deal with the 'wireless' file in the following location

• /etc/pm/power.d
• /usr/lib/pm-utils/power.d

but those doesn't work for me, and it might happen to you as well. If that is the case, you can still solve it by manual enter the following command into terminal:

• iwconfig eth1 power off

Please note that the "eth1" has to be your wireless interface. Some might name after "wlan1". You have to enter the command every time you reboot a new session. I have not found any working method to execute this command during start up, if you do found it, please share with me.

[Ubuntu] How to release/renew IP when dhclient doesn't work.

I have encountered a very weird issue with Ubuntu 12.10 wireless networking where dhclient -r and dhclient cannot work as expected. The wireless device lock to the same IP, and unable to connect to internet or any other shared resources in the network.

Any other methods such as:

1. Delete the profile in network manager
2. restart networking service
3. ifdown and ifup the interface
4. Manually set IP address & DNS server
5. Restart the router

Do not work as well. So what's the real fix for this problem? If you ever encounter the same problem as I did, you might try delete all the DHCP lease file located in /var/lib/dhcp/. New one will be generated automatically. Here's how my DHCP folder look alike:

If delete doesn't work for you, give me five because we are having the same issue. When I open the folder, there are multiple files inside, I deleted all (make sure you have turn off you wireless device before doing so) and let the system generates a new one.

After that, open up the new files with root privilege leafpad (or any other text editor), you will see the following:

 lease {  
  interface "eth1";  
  fixed-address 192.168.1.122;  
  option subnet-mask 255.255.255.0;  
  option routers 192.168.1.1;  
  option dhcp-lease-time 50400;  
  option dhcp-message-type 5;  
  option domain-name-servers 202.188.0.133,202.188.1.5;  
  option dhcp-server-identifier 192.168.1.1;  
  option dhcp-renewal-time 25200;  
  option dhcp-rebinding-time 44100;  
  renew 5 2013/02/01 22:24:39;  
  rebind 6 2013/02/02 04:55:53;  
  expire 6 2013/02/02 06:40:53;  
 }  

It's very simple here, modify the 10.0.0.122 192.168.1.122 (Updated: 25 Nov 2014) to some other available IP address, save it and turn on your wireless device. Wait for a few seconds and voila!

Most probably you are now able to online and start surfing. And if this does help, please leave me a comment so at least I know my blog help others. Cheers~!