My Nexus 4 device stopped connecting to the Cisco router at work for some reason. I thought it was because the upgrade to lollipop 5.0 (had Kit-Kat before) but I'm not so sure anymore.

I tried:

  • Restart the device
  • Restart the device with safe mode
  • Restart the router
  • Change the device WiFi frequency settings
  • Use static IP at the advance WiFi connection configuration
  • Forget the router AP and reconnect
  • Factory reset trough the device settings, recovery mode and complete flashing the Android Lollipop 5.1 factory image.

After factory reset I had the connection possible until restarting the device. I checked with/without signing in, nothing new installed, didn't visit the store, just super clean phone - I could connect the network. after restarting the phone I can no longer connect which means it's not an application issue.

Some facts:

  • I can connect other Cisco routers at work
  • Another Nexus 4 after factory reset connects with no trouble

About the device:

  • Nexus 4
  • Lollipop 5.1
  • build number LMY470
  • kernel version 3.4.0-perf-gf75bb4f

Any suggestion will be welcome, please let me know if I can provide more details.

  • 1
    It sounds like one of your apps is causing the problem. You may have to reload them one-by-one until you find the culprit.
    – Joe Sewell
    Commented Apr 27, 2015 at 20:37
  • sounds so. do you know an easy way to do it? should I restart after each app uninstallation?
    – Tamir
    Commented Apr 27, 2015 at 20:38
  • That might be easier than a factory reset followed by installing one at a time until it stops working. The problem, though, is that the culprit app might have modified a setting that won't get cleared without a factory reset.
    – Joe Sewell
    Commented Apr 27, 2015 at 20:40
  • @JoeSewell It doesn't seems like app issue. I updated the question.
    – Tamir
    Commented Apr 28, 2015 at 7:19

1 Answer 1


Some sites recommend to restart the router device, and sometime it works. Instead of every time restart the router to solve this Android 5.1 Wi-Fi problem, it worked for me:

Inside the router configuration (e.g., accessing the IP, change the "Group key update" value from 0 to 30 seconds, under the "Wireless > Security" configuration, right below the WPA-PSK/WPA2-PSK item.

My router model is: TP-LINK TL-WR740N / TL-WR740ND.

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