Ubuntu – Network Manager troubleshooting

If you're having a problem with Network Manager it's likely a problem with the driver. Since it's been a few years then you're probably better off with sticking with the default unless you have a problem.

There are two ways to fix wireless problems in Linux. Fixing the driver or working around it.

As Dan Williams (who is one of the main developer's for network-manager) has chronicled in his blog, sometimes it takes a long time; there are many moving parts, the kernel, the applet, and talking to the manufacturer of the hardware (if they even care) and then getting all that shipped to users. This takes longer than working around the issue, but in the end is a more sustainable model and gets everyone better drivers in the end. Network Manager and WICD don't exactly have the same feature set yet. WICD tends to deal well with wireless and basic ethernet connectivity, but doesn't yet support VPNs, DSL, 3G/CDMA and many other features which are becoming more and more popular.

This isn't meant as a slight towards the WICD folks, it does help people get online and that's great, but fixing it all the way down the stack is a better overall for Linux. Bottom line is, you can choose whichever application you happen to prefer, but if NetworkManager works for you, sticking to the default is probably what will get you the best results in the long run, since you will be able to benefit from the other features if you end up needing them. Network Manager, as the default network tool in Ubuntu is also supported by the Ubuntu team.

The linux wireless project maintains a page of wireless cards and chipsets and what features they support, and is a good guide to supporting manufacturers that maintain good drivers.

To fix this, you are going to remove and reinstall your kernel WiFi Device driver

1. First you need to find your WiFi device driver module name using lshw

   lshw -C network

   you will get a lot more output that this, but the key lines are:

   *-network                 
     description: Wireless interface
    . . . 
    configuration: broadcast=yes driver=iwlwifi driverversion=5.3.0-40-generic firmware=17.3216344376.0 ip=10.127.128.165 latency=0 link=yes multicast=yes wireless=IEEE 802.11
   

   or

    configuration: autonegotiation=on broadcast=yes driver=r8169 firmware=rtl8168g-2_0.0.1 02/06/13 latency=0 
   

   you are looking for the driver name in this case driver=iwlwifi or driver=r8169

2. Now, using the driver name, do the restart:

   sudo modprobe -r iwlwifi && sudo modprobe iwlwifi
   

3. Make a shell script to do this for you, because, if you are like me, you will forget these steps, and when you need them it will be when your wireless adapter is not working.

   A. edit a file somewhere in you search path, like ${HOME}/bin/resetWireless adding contents that do this:

   #!/bin/bash
   sudo lshw -C network | grep capabilities | grep driver
   echo if that last command did not say that the driver is iwlwifi then change the next line
   sudo modprobe -r iwlwifi && sudo modprobe iwlwifi
   ## This is from https://askubuntu.com/questions/1169349/keep-needing-to-restart-network-manager-for-wifi-to-work
   

   B. make the file executable with:

   % chmod +x ${HOME}/bin/resetWireless
   

if this works for you, please head over to the place I got it and +up the answer there, because this is a repeat of woulter's answer from How to restart WiFi interface without rebooting (it drops connection)? edited Dec 16 '16 at 8:21 answered Feb 9 '16 at 16:51 Wouter