Troubleshooting

Since the introduction of NetworkManager, connections can be enabled and disabled from the NetworkManager icon in the System Notification Area.

[Important]

Before attempting any troubleshooting, ensure that the connection is enabled:

  1. Right click the NetworkManager icon in the notification area.

  2. Check Enable Networking.

  3. Check Enable Wireless.

Wired troubleshooting

If you have a network connection that is not working properly, you can use a few tools to help diagnose what the problem is.

Most of the tools in this section require use of the Terminal, which you can open by pressing ApplicationsAccessoriesTerminal.

Get Information About the Current Connection

ifconfig is intended to allow you to change the settings of your network connections, but it can also be used to list information about the current connection.

  1. Press ApplicationsAccessoriesTerminal to open a Terminal

  2. Type the following in the Terminal and press Enter:

                      
                        ifconfig
                      
                    

    The following information is a portion of the computer output of the command:

    • logical or connection name(s) of the various wired or wireless network devices your computer may have is located in the left column (i.e. eth1)

    • in the right column, inet addr gives the current IP address (i.e. 192.168.0.100) of the corresponding network device

    • HWaddr gives the MAC address of your network device

Check If a Connection Is Working Properly

A good way of checking if a connection is working properly is to ping another computer on the network or the Internet.

To check if you are connected to the Internet:

  1. Open a Terminal (ApplicationsAccessoriesTerminal) and type the command:

                      
                        ping -c 3 www.xubuntu.org
                      
                    
  2. The terminal will display three instances of your computer attempting to ping www.xubuntu.org. Look at the ping statistics section that displays how many packets were transmitted, how many were receieved, the percentage of packet loss and the total time that transpired to send the 3 packets to www.xubuntu.org.

    • 0% packet loss - Your computer should have a good connection to the Internet

    • Greater than 0% but less than 100% packet loss - Your computer probably has a poor connection to the Internet or a poor wireless signal

    • 100% packet loss - Your computer has a very bad connection, or is connected to an access point or router that is not connected to the Internet

If you get an error message that says www.xubuntu.org can not be found or unknown host, then your computer is probably not connected to the Internet or can not reach a Domain Name System (DNS) server.

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 Connection” and should that fail, start at the beginning 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

Open a Terminal (ApplicationsAccessoriesTerminal) 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 - move on to see if there is a driver listed then 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

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

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

  2. Install the ndisgtk package.

  3. Open ndisgtk (ApplicationsSystemWindows 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 (ApplicationsAccessoriesTerminal) and type the command:

                      
                        iwconfig
                      
                    

  2. If the ESSID for your 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 (ApplicationsAccessoriesTerminal) 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 eth1
                      
                    

    replace eth1 with the name of the connection outputted from the ifconfig command.

  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 (ApplicationsAccessoriesTerminal) and type the command:

                      
                        ping -c 3 91.189.94.141
                      
                    

  2. Now type the command:

                      
                        ping -c 3 www.xubuntu.org
                      
                    

    If you get a response from both commands, then see the section called “Issues With IPv6.

  3. Type the command:

                      
                        cat /etc/resolv.conf
                      
                    

    If there is no nameserver listed, then contact your Internet Service Provider (ISP), and find out your primary and secondary domain name servers. Once you have this information see the section called “Wireless Connection”.

Issues With IPv6

Internet Protocol version 6 (IPv6) is supported by default in Xubuntu. If you believe you are experiencing issues using IPv6, then you can disable it by following these steps:

  1. Open a Terminal (ApplicationsAccessoriesTerminal) and type the following commands:

                      
                        sudo nano /etc/default/grub
                      
                    

    and press Enter.

  2. Locate the line that contains GRUB_CMDLINE_LINUX=

  3. Input ipv6.disable=1 in between the quotes, i.e. GRUB_CMDLINE_LINUX="ipv6.disable=1"

  4. Press Ctrl+X to exit the nano program.

  5. Press Y and then Enter to save the changes to /etc/default/grub.

  6. Type in the Terminal:

                      
                        sudo update-grub
                      
                    

    and press Enter.

  7. Reboot Xubuntu.

  8. To verify that IPv6 has been disabled, open a Terminal (ApplicationsAccessoriesTerminal) and type the command:

                      
                        cat /proc/sys/net/ipv6/conf/all/disable_ipv6
                      
                    

  9. The output or response from the computer will either be 0 which means that IPv6 is not disabled or 1 which means IPv6 is disabled. After following these steps, the output should be 1.