I'm trying to connect to my school network from Ubuntu 12. The network is WPA encrypted and I can connect just fine if the network manager establishes a connection automatically. However, when I get disconnected and try to reconnect a username and password prompt pops up. The credentials are already stored and are autofilled in correctly, but the Connect button is disabled so I can't actually connect to the network.

What can I do? The only guess I've found so far is the password is too short and Ubuntu is expecting a full WPA key. I don't administer the school network though so I certainly can't change that.

  • 2
    If you're connecting with username and password, then it's radius-based WPA-eap, so there is no wpa key.
    – week
    Dec 5, 2012 at 14:55
  • Just want to confirm that you can connect to other wifi network. Also please add output if "iwconfig".
    – John Siu
    Dec 17, 2012 at 21:04

2 Answers 2


This is indeed a minimum password length issue as you stated. The funny thing is that when the connection is made automatically, Ubuntu doesn't seem to complain. It's only when a connection is attempted through the GUI that the problem occurs.

You could try to restart networking...


sudo /etc/init.d/networking restart


sudo service networking restart

Or... you could try using a script to get a connection...

#! /bin/bash
ifconfig wlan0
iwconfig wlan0 essid [NETWORK_ID] [key WIRELESS_KEY]
dhclient wlan0

This assumes your interface is called wlan0.


Try the following to restart the Ubuntu network manager applet:

killall nm-applet; nm-applet

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