I too ran into problems with USB Wi-Fi dongle on RPi. After being on for roughly a day RPi loses Wi-Fi link. If I run ping to the gateway command fails with "Destination host not reachable" message. People seem to solve problem by issuing ifdown wlan0 followed by ifup wlan0. Unfortunately it doesn't work for me. Only way I can get connection back is to physically unplug USB dongle and plug it again. How can I imitate physical reset with console commands as close as possible?

  • 4
    Possible duplicate of How can I reset a USB device using command line utilities?
    – goobering
    Commented Feb 17, 2016 at 11:27
  • You can remove the modules that manage the device from the kernel, reinsert them, and restart the relevant services (wpa_supplicant, NetworkManager etc.).
    – kba
    Commented Feb 17, 2016 at 11:28
  • This turned out to help only temporarily. Even physically reseating USB dongle helps only for 3-4 minutes and then Wi Fi signal disappears again. I figured out best solution is to add a cron job to periodically ping gateway and reset Pi if no response is received.
    – Farid83
    Commented Feb 25, 2016 at 7:56

2 Answers 2


Sounds like a power management setting for your wireless needs to be updated. Run iwconfig and look for a line like this:

Power Management:off

If you see "on" instead of "off" you will need to update doing the following:

Type at the command line: sudo nano /etc/network/interfaces

Insert this text anywhere: wireless-power off

Save the doc, close, and then at the command line type: /etc/init.d/networking restart

Check iwconfig output again to make sure the power management setting took.


What type of dongle is it? there's a tweak to turn off power management on Realtek 8192CU Based Wifi Modules


  • I'm using ASUS N10 which is based on RTL8192SU. But I figured out resetting Pi would be the best option.
    – Farid83
    Commented Feb 25, 2016 at 7:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.