How to troubleshoot Wireless network issues in Ubuntu Linux on your Dell PC

Table of Contents:

1. Troubleshooting a Wireless Network Issue
2. Identifying any issues outside the system
3. Troubleshooting the Hardware
4. Troubleshooting the Software
5. Resolution

Troubleshooting a Wireless Network Issue

This troubleshooting guide can help you resolve wireless network (Wi-Fi) issues for systems with the Ubuntu Linux Operating System (OS).

If your system has a Windows OS installed, refer to the article:

• How to resolve Wireless Networking issues on my Dell computer.

Identifying any issues outside the system

1. Can your system detect local Wi-Fi networks, but it cannot connect to them?

   1. If it can see networks and connect to any other network but yours, contact your Internet Service Provider ISP. The network itself or your connection settings may be at fault.

   2. If it can see networks but cannot connect to any, and your Wi-Fi strength is low, proceed with Step 2.

   3. If it cannot see any networks even when physically held over the router, proceed with Step 2.

   4. If it can intermittently see and connect to available wireless networks, proceed to hardware troubleshooting.

   5. If it does not detect your installed Wi-Fi card, proceed to Step 3.

2. Can other devices connect to the Wi-Fi?

   1. If they can, carry on with the guide.

   2. If not, contact your ISP about a general network issue.

3. If you boot the system to the Basic Input Output Setup (BIOS), can you see the installed Wi-Fi card?

   1. If it is detected, then proceed with the guide.

   2. If it is not detected, proceed to hardware troubleshooting.

4. In the BIOS check that the wireless is enabled and disable the Wi-Fi switch if your system has one installed. Boot back to the OS and confirm if the issue continues?

   1. It does, proceed with the guide.

   2. It does not, go back into the bios and reenable the Wi-Fi switch. If the fault comes back contact your Technical Support to resolve this issue. If the fault does not come back, your issue should be resolved.

   3. It does not have a switch, proceed to the next step.

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Troubleshooting the Hardware

1. Boot from the Ubuntu Linux Media, either a CD or a USB and advise if the issue occurs while in that OS?

   1. If it works fine, you are looking at a clean install and driver reinstall.

   2. If it is the same, please proceed with this guide.

2. The best way to rule out a hardware issue is to two-way swap the Wi-Fi card with another compatible system.

   1. You could swap out the Wi-Fi card and:

      1. The fault followed the original card to the working system, and the card from the working system works in your machine. Contact your technical support to have the hardware issue resolved.

      2. The fault stays with the working card in your system and your card is working fine in the working machine. Continue with this guide.

      3. The fault goes away on both machines. It was a loose connection and your issue should be resolved.

   2. If that is not possible, then reseat the Wi-Fi card and antenna cables:

      1. If the situation changes and the Wi-Fi starts to work, it was a loose connection and your issue should be resolved.

      2. If your issue continues, please proceed with the next step.

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Troubleshooting the Software

1. Run the following troubleshooting steps on the wireless adapter to confirm the adapter is recognized:

   1. Open Terminal (CTRL+Alt+T)

   2. Get the details from the adapter and connection status using the following command:

      sudo nmcli device

      Check if the output state contains connected. If it does, the card is connecting.

   3. If not, you can get more details from the adapter using the following commands:

      sudo lshw -businfo
sudo lshw -c network

   4. You should get a result that looks something like this:

      product: Intel8720A Wireless Network Adapter

   5. Is the wireless device listed?

      1. If the wireless device is listed correctly, you should reinstall the device drivers.

      2. The wireless device is not listed correctly, proceed to the next step.

2. Follow the steps for your device connection type:

   1. If your wireless device is an internal PCI device, type the following command:

      lspci

   2. If your wireless delice is a USB dongle device, type the following command:

      lsusb

3. Can you identify your device from the lists generated?

   1. If the wireless device is now listed correctly under PCI or USB, you should reinstall the device drivers.

   2. The wireless device is not listed correctly, you should contact your Technical Support.

4. Scan for networks using NetworkManager. Click the NetworkManager on your menu bar.

5. The dropdown menu will show a list of wireless networks in range. Select from the list to connect.

   1. It shows the available networks but will not connect to any. Proceed with the next step.

   2. It does not see any networks. Contact your Technical support to resolve this issue.

6. Scanning from the command line is another option. Click Dash Home > Search > Terminal. The Terminal program will launch.

7. Enter the following command in terminal:

   sudo iwconfig

8. The system will display a list of network adapters:

   eth0

   No wireless extensions

   lo

   No wireless extensions

   wlan0

   IEEE 802.11bgn ESSID:off/any mode: Managed Access Point: Not-Associated Tx-Power: 16dBm Sensitivity=0/3 Retry long limit: 7 RTS thr: off Fragment thr: off Power Management: off

   wlan0

   Is the wireless adapter entry

9. Enter the following command in terminal: (Where <ethX> is the name of the wireless adapter as found in the last command.)

   sudo iwlist <ethX> scan

10. The system will scan for access points and return a list of the ones it has found. The output from the scan will contain some useful information. Look for these pieces of information that might help your troubleshooting.

    ESSID

    This is the wireless network name, SSID

    Mode

    This is the wireless network access mode, Managed=Access Point Mode

    Quality

    This number indicates the signal quality, from 1 - 5

    Encryption key

    This indicates if this network requires an encryption key.

11. Enter the following command in terminal: (Where -c 4 means 4 echo requests and 127.0.01 is the loopback address.)

    sudo ping -c 4 127.0.0.1

    If the loopback does not work, then it could be an issue with the TCP/IP stack.

    You can also ping your router's IP address, an external site using either its IP address, or common name. If it connects to an address, but not a common name then it could be a DNS issue

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Resolution

1. Do the results point to a hardware or software issue?

   1. If the Hardware is faulty contact your Technical Support with the troubleshooting you have done, to get the issue resolved.

   2. If the hardware is verified to be working, but your issue persists? The next step would be to get in touch with Canonical the suppliers of Ubuntu Linux and the built-in drivers. They can take you through in-depth software and driver troubleshooting to resolve your issue. You can find all of their information about the Ubuntu Community Support  page. As well as a community support group that will also attempt to resolve any issues that remain.

If at any point what you see differs from what is described, please contact your technical support for further aid to resolve the problem.

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Additional Information:

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