connect wifi via terminal bactrack

root@bt:~# iwconfig
root@bt:~# ifconfig wlan1 up
root@bt:~# iwlist wlan1 scan
root@bt:~# iwconfig wlan1 essid   "......."
root@bt:~# dhclient
===================================
root@bt:~# iwconfig
lo        no wireless extensions.

wlan1     IEEE 802.11bgn  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=off 
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

wlan0     IEEE 802.11bgn  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=off 
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
        
eth0      no wireless extensions.


root@bt:~# ifconfig wlan1 up
root@bt:~# iwlist wlan1 scan
wlan1     Scan completed :
          Cell 01 - Address: 00:65:EC:8E:83:A8
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=44/70  Signal level=-66 dBm 
                    Encryption key:off
                    ESSID:"INET 007"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=0000009da905e1bc
                    Extra: Last beacon: 1088ms ago
                    IE: Unknown: 0000
                    IE: Unknown: 010882848B960C121824
                    IE: Unknown: 030101
                    IE: Unknown: 050400010000
                    IE: Unknown: 2A0104
                    IE: Unknown: 32043048606C
          Cell 02 - Address: 06:77:7F:D9:AE:A8
                    Channel:4
                    Frequency:2.427 GHz (Channel 4)
                    Quality=22/70  Signal level=-88 dBm 
                    Encryption key:off
                    ESSID:"FREE WIFI"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000737d4ec181
                    Extra: Last beacon: 768ms ago
                    IE: Unknown: 000A4A4159415F4C41524153
                    IE: Unknown: 010882848B960C121824
                    IE: Unknown: 030104
                    IE: Unknown: 05050001000008
                    IE: Unknown: 2A0100
                    IE: Unknown: 32043048606C
                    IE: Unknown: DD0900037F01010020FF7F

root@bt:~# iwconfig wlan1 essid "FREE WIFI"
root@bt:~# dhclient
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

SIOCSIFFLAGS: Unknown error 132
Listening on LPF/wlan1/45:56:a8:7a:96:a5
Sending on   LPF/wlan1/45:56:a8:7a:96:a5
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 5
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
send_packet: Network is down
DHCPDISCOVER on wlan1 to 255.255.255.255 port 67 interval 7
receive_packet failed on wlan0: Network is down
DHCPOFFER of 192.168.30.67 from 192.168.1.1
DHCPREQUEST of 192.168.30.67 on wlan1 to 255.255.255.255 port 67
DHCPACK of 192.168.30.67 from 192.168.1.1
bound to 192.168.1.67 -- renewal in 129 seconds.
root@bt:~#