This troubleshooting guide can help you resolve wireless network (Wi-Fi) issues for laptops and desktops with the Ubuntu Linux Operating System.
If your laptop or desktop has a Windows operating system installed, see the following article:
Can your laptop or desktop detect local Wi-Fi networks, but it cannot connect to them?
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.
If it can see networks but cannot connect to any, and your Wi-Fi strength is low, proceed with Step 2.
If it cannot see any networks even when physically held over the router, proceed with Step 2.
If it can intermittently see and connect to available wireless networks, go to hardware troubleshooting.
If it does not detect your installed Wi-Fi card, go to Step 3.
Can other devices connect to the Wi-Fi?
If they can, carry on with the guide.
If not, contact your ISP about a general network issue.
If you boot the laptop or desktop to the Basic Input Output Setup (BIOS), can you see the installed Wi-Fi card?
If it is detected, then proceed with the guide.
If it is not detected, go to hardware troubleshooting.
In the BIOS check that the wireless is enabled and disable the Wi-Fi switch if your laptop or desktop has one installed. Boot back to the operating system and confirm if the issue continues?
It does, carry on with your troubleshooting.
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.
It does not have a switch, go to the next step.
Boot from the Ubuntu Linux Media, either a CD or a USB and advise if the issue occurs while in that operating system?
If it works, you are looking at a clean install and driver reinstall.
If it is the same, proceed with the next step.
The best way to rule out a hardware issue is to two-way swap the Wi-Fi card with another compatible laptop or desktop.
You could swap out the Wi-Fi card and:
The fault followed the original card to the working laptop or desktop, and the card from the working product works in your laptop or desktop. Contact your technical support to have the hardware issue resolved.
The fault stays with the working card in your laptop or desktop and your card is working fine in the working machine. Go to this guide.
The fault goes away on both devices. It was a loose connection, and your issue should be resolved.
If that is not possible, then reseat the Wi-Fi card and antenna cables:
If the situation changes and the Wi-Fi begins to work, it is a loose connection, and your issue should be resolved.
If your issue continues, proceed with the next step.
Run the following troubleshooting steps on the wireless adapter to confirm that the adapter is recognized:
Open Terminal CTRL+ALT+T
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 connected.
If not, you can get more details from the adapter using the following commands:
sudo lshw -businfo
sudo lshw -c network
You should get a result that looks something like this:
product: Intel8720A Wireless Network Adapter
Is the wireless device listed?
If the wireless device is listed correctly, reinstall the device drivers.
The wireless device is not listed correctly, go to the next step.
Follow the steps for your device connection type:
If your wireless device is an internal Peripheral Component Interconnect (PCI) device, type the following command:
lspci
If your wireless device is a USB dongle device, type the following command:
lsusb
Can you identify your device from the lists generated?
If the wireless device is now listed correctly under PCI or USB, reinstall the device drivers.
The wireless device is not listed correctly, you should contact your Technical Support.
Scan for networks using NetworkManager. Click the NetworkManager on your menu bar.
The dropdown menu shows a list of wireless networks in range. Select from the list to connect.
It shows the available networks but does not connect to any. Proceed with the next step.
It does not see any networks. Contact your Technical support to resolve this issue.
Scanning from the command line is another option. Click Dash Home > Search > Terminal. The Terminal program launches and opens a window with a prompt.
Enter the following command in the terminal:
sudo iwconfig
The laptop or desktop displays a list of network adapters:
No wireless extensions
No wireless extensions
IEEE 802.11bgn ESSID: off/any mode: Managed Access Point: Not-Associated Tx-Power: 16 dBm Sensitivity=0/3 Retry long limit: Seven RTS thr: off Fragment thr: off Power Management: off
Is the wireless adapter entry
Enter the following command in the terminal: (Where <ethX> is the name of the wireless adapter as found in the last command.)
sudo iwlist <ethX> scan
The laptop or desktop scans for access points and returns a list of the ones that it has found. The output from the scan contains some useful information. Look for these pieces of information that might help your troubleshooting.
This is the wireless network name, SSID
This is the wireless network access mode, Managed=Access Point Mode
This number indicates the signal quality, from 1 - 5
This indicates if this network requires an encryption key.
Enter the following command in the terminal: (Where -c 4 means four 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.
Do the results point to a hardware or software issue?
If the Hardware is faulty contact your Technical Support with the troubleshooting, you have done to get the issue resolved.
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 integrated drivers. They can take you through in-depth software and driver troubleshooting to resolve your issue. You can find all their information about the Ubuntu Community Support page. There is a community support group that attempts to resolve any software issues that remain.
If at any point what you see differs from what is described, contact your technical support for further aid to resolve the problem.