Successful connect to WPA2 with Linux Mint 17

I found myself having odd problems connecting to WPA2 encrypted wireless networks with a new laptop. There must be more elegant solutions to this problem, but this worked for me. The problem was that I couldn’t connect to a nearby hotspot secured with WPA2 whether I used the default config tool for mint, Wicd Network Manager, or the command line. Errors were either “bad password” or the more detailed errors below.

As with any system variation mileage may vary, my errors look like:

wlan0: CTRL-EVENT-SCAN-STARTED 
wlan0: SME: Trying to authenticate with 68:72:51:00:26:26 (SSID='WA-bullet' freq=2462 MHz)
wlan0: Trying to associate with 68:72:51:00:26:26 (SSID='WA-bullet' freq=2462 MHz)
wlan0: Associated with 68:72:51:00:26:26
wlan0: CTRL-EVENT-DISCONNECTED bssid=68:72:51:00:26:26 reason=3 locally_generated=1

and my system config is reported as:

# lspci -vv |grep -i wireless
3e:00.0 Network controller: Intel Corporation Wireless 7260 (rev 6b)
 Subsystem: Intel Corporation Dual Band Wireless-AC 7260
# uname -a
Linux dgzb 3.16.0-38-generic #52~14.04.1-Ubuntu SMP Fri May 8 09:43:57 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

I found useful commands for manually setting up a wpa_supplicant.conf file here, and for disabling 802.11n here. The combination was needed to get things working.

The following successfully connects to a WPA2-secured network:

$ sudo su
$ iw dev
 ... Interface [interfacename] (typically wlan0, assumed below)
$ iw wlan0 scan
 ... SSID: [ssid]
 ... RSN: (if present means the network is secured with WPA2)
$ wpa_passphrase [ssid] >> /etc/wpa_supplicant.conf 
...type in the passphrase for network [ssid] and hit enter...
$ sh -c 'modprobe -r iwlwifi && modprobe iwlwifi 11n_disable=1'
$ wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf

(should show CTRL-EVENT-CONNECTED)
(open a new terminal leaving the connection open, ending the command disconnects)

$ sudo su
$ dhclient wlan0

(should be connected now)