wpa2 无线命令怎么弄？

[linuxier]

无线网卡：
03:00.0 Network controller: Intel Corporation PRO/Wireless 5100 AGN [Shiloh] Network Connection
所用驱动：
aptitude show firmware-iwlwifi
Package: firmware-iwlwifi
New: yes
State: installed
Automatically installed: no
Version: 0.27
Priority: optional
Section: non-free/kernel
Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>
Uncompressed Size: 3,043 k
Suggests: initramfs-tools, linux-image
Description: Binary firmware for Intel Wireless 3945, 4965 and 5000-series cards
This package contains the binary firmware for Intel Wireless 1000, 3945, 4965, 5100, 5300, 6000 and 6250 cards supported by the iwl3945 and iwlagn drivers.

Contents:
* Intel Wireless 1000 firmware, version 128.50.3.1 (iwlwifi-1000-3.ucode)
* Intel Wireless 3945 firmware, version 15.28.1.6 (iwlwifi-3945-1.ucode)
* Intel Wireless 3945 firmware, version 15.32.2.9 (iwlwifi-3945-2.ucode)
* Intel Wireless 4965 firmware, version 228.57.1.21 (iwlwifi-4965-1.ucode)
* Intel Wireless 4965 firmware, version 228.61.2.24 (iwlwifi-4965-2.ucode)
* Intel Wireless 5100, 5300 and 5350 firmware, version 5.4.A.11 (iwlwifi-5000-1.ucode)
* Intel Wireless 5100, 5300 and 5350 firmware, version 8.24.2.12 (iwlwifi-5000-2.ucode)
* Intel Wireless 5150 firmware, version 8.24.2.2 (iwlwifi-5150-2.ucode)
* Intel Wireless 6000 firmware, version 9.193.4.1 (iwlwifi-6000-4.ucode)
* Intel Wireless 6250 firmware, version 9.201.4.1 (iwlwifi-6050-4.ucode)
Homepage: http://intellinuxwireless.org/?p=iwlwifi&n=downloads

装上上面这个驱动后在 kde 界面我可以用 network manager 连上无线，但有时我不想用 kde，请问命令怎么配置 wpa 无线？

我在网上看了下，主要有下面几步，
wpa_passphrase YOUR-SSID PASSWORD
wpa_supplicant -B -i IFACE -Dwext -c /etc/wpa_supplicant.conf # driver 我这里还用 wext 么？
iwconfig IFACE
dhclient IFACE

我就在第三步检查网卡时出现的还是 not associate, 当然也就连不上了。