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I have two RasPi3, both on the newest Jessie and updated && upgraded. The problem is that both Pis can see networks but are not connecting to them. 

sudo iwlist wlan0 scan

Gives me multiple networks including the one I want to connect to. Typing in the credentials and authentication into the wpa_supplicant.conf file doesn't work. Then I installed xrdp on the Pis to see if a connection over that is possible. Again I see available networks including the one I want to connect to. I click it, type in the requested key and nothing happens. Afterwards a mouseover on the networks button in the upper right corner shows "wlan0 not associated". 

sudo ifup wlan0

tells me that the wlan0 interface is already configured. Makes sense. The newest firmware for the WiFi chip on the board is installed.

When I set the Pis up, they connected without any problems. Even to the same network as they should now. Nothing changed in the meantime.

What can I try?

EDIT: Just tested to connect to my phone using the mobile hotspot. No problem at all...It gets confusing.

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  • Have you tried (shock! horror!) the Foundation Guidelines raspberrypi.org/documentation/configuration/wireless/README.md Commented Jul 8, 2016 at 10:17
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    They are useless as they tell me what I just described and I can't use wpa_gui anymore in the new raspbian jessie releases. Commented Jul 8, 2016 at 10:42
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    Then there is always the dark side. Presuming you have a correct wpa_supplicant.conf, it actually only takes two or three commands to manually connect, -- ip link set wlan0 up (maybe superfluous), wpa_supplicant ..., and dhclient.... This may make it easier to figure out what's wrong, but first you have to disable autoconfiguration, dhcpcd, etc.. Commented Jul 8, 2016 at 12:25
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    Yes by using a WiFi dongle instead of the onboard WiFi. Disabled the onboard WiFi using a blacklist. Works perfectly fine. But couldn't find the reason why it was not working normally. Commented Dec 16, 2016 at 10:55
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    @goldilocks answer works like a charm on my Pi3. ip link set wlan0 up. Commented Dec 18, 2016 at 23:55

1 Answer 1

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To work withwpa_supplicant on some routers and networks can be pretty tricky and hard to diagnose. Using the following method I have a 100% success rate.
First to confirm your network is available and visible try (just the SSID is enough):

 iwlist wlan0 scan | grep SSID

Then create a network credential entry for supplicant with:

wpa_passphrase "<ssid>" "<password>" >> /etc/wpa_supplicant/wpa_supplicant.conf

Note ssid (and password) are case sensitive.

This will create a 64 char PSK as follows: 

network={ ssid="ssid" #psk="password" psk=44116ea881531996d8a23af58b376d70f196057429c258f529577a26e727ec1b }

You may edit your .conf to remove (or '#' comment) the replaced network.

This network definition will be enough to associate/register. You don't need the usual parameters like: 

proto=WPA WPA2 pairwise=CCMP TKIP group=CCMP TKIP key_mgmt=WPA-PSK WPA-EAP

If this is not working, you can debug it running supplicant in debug mode, be a fast reader or use ^S/^Q on your console to pause it:

wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf -B -D

If wpa_supplicant is running on wlan0 you will receive the message:

Successfully initialized wpa_supplicant ctrl_iface exists and seems to be in use - cannot override it Delete '/var/run/wpa_supplicant/wlan0' manually if it is not used anymore Failed to initialize control interface 'DIR=/var/run/wpa_supplicant GROUP=netdev'. You may have another wpa_supplicant process already running or the file was left by an unclean termination of wpa_supplicant in which case you will need to manually remove this file before starting wpa_supplicant again.

Just kill the running version, in this example is process '651' (second column, after 'root'):

> ps aux | grep supplicant root 651 0.0 0.7 7244 3516 ? Ss 15:20 0:00 /sbin/wpa_supplicant -s -B -P /run/wpa_supplicant.wlan0.pid -i wlan0 -D nl80211,wext -c /etc/wpa_supplicant/wpa_supplicant.conf root 1651 0.0 0.4 4272 1844 pts/0 S+ 16:35 0:00 /bin/grep --color supplicant > kill 651

and try again.

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  • Hello, first I tried with WEP network, so in my /etc/wpa_supplicant/wpa_supplicant.conf file there was old WEP setting (even I rebooted RP3). I deleted old one, and it worked. Commented Mar 11, 2017 at 11:15
  • you saved my life trying to fix this from few days, thank you! Commented Mar 22, 2019 at 16:17

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