Ubuntu Documentation > Ubuntu 9.04 > Internet and Networks > Troubleshooting > Wireless troubleshooting

Wireless troubleshooting

While not exhaustive, this section covers some common problems faced with wireless support.

There is much more information available from the Community Documentation.

[Note]

This troubleshooting guide is designed to be carried out in order. If you reach the end of a section and are not directed to another - then try the section called “Wireless” and should it fail begin at the start again.

Check that the device is on

  1. Many wireless network devices can be turned on or off. Check to see if there is a hardware switch, some devices can be switched off from Windows and may need to be turned back on from Windows.

  2. If it is turned on then see the section called “Check for device recognition”.

Check for device recognition

  1. Open a Terminal (Applications → Accessories → Terminal) and type the command: sudo lshw -C network

You should see an output, along with the words "CLAIMED, UNCLAIMED, ENABLED or DISABLED"

  1. Claimed - this indicates a driver is loaded but not functioning, see the section called “Using Windows Wireless Drivers”

  2. Unclaimed - there is no driver loaded, see the section called “Using Windows Wireless Drivers”.

  3. Enabled - there is a driver loaded, see the section called “Check for a connection to the router”.

  4. Disabled - see the section called “Check that the device is on”.

Using Windows Wireless Drivers

Ubuntu supports a system known as NDISWrapper. This allows you to use a Windows wireless device driver under Ubuntu.

  1. Obtain the Windows Driver for your system and locate the file that ends with .inf.

  2. Install the ndisgtk package.

  3. Open ndisgtk (System → Administration → Windows Wireless Drivers).

  4. Select Install new driver.

  5. Choose the location of your Windows .inf file and click Install.

  6. Click OK.

Check for a connection to the router

  1. Open a Terminal (Applications → Accessories → Terminal) and type the command: iwconfig.

  2. If the ESSID for our router is shown there may be a problem with ACPI support. Boot the kernel with the pci=noacpi option.

Check IP assignment

  1. Open a Terminal (Applications → Accessories → Terminal) and type the command: ifconfig.

  2. If there is an IP address shown see the section called “Check DNS”.

  3. From the Terminal enter the command: sudo dhclient if_name where if_name is the connection listed earlier.

  4. If you receive a message that says bound to xxx.xxx.xxx.xxx then see the section called “Check DNS”

  5. If not then reboot the system.

Check DNS

  1. Open a Terminal (Applications → Accessories → Terminal) and type the command: ping -c3 85.190.27.2.

  2. Now type the command: ping www.ubuntu.com. If you get a response from the both then see the section called “IPv6 Not Supported”.

  3. Type the command: cat /etc/resolv.conf. If there is no nameserver listed then contact your ISP and find out your primary and secondary domain name servers. Once you have this information see the section called “Wireless”.

IPv6 Not Supported

  1. IPv6 is supported by default in Ubuntu and can sometimes cause problems.

  2. To disable it, open a Terminal (Applications → Accessories → Terminal) and type the command: gksudo gedit /etc/modprobe.d/aliases.

  3. Find the line alias net-pf-10 ipv6 and change it to read alias net-pf-10 off.

  4. Reboot Ubuntu.

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Wired troubleshooting  Home  Chapter 6. Modems